Coverity and build fixes from Nelson

[sxemacs] / src / fileio.c

/* File IO for SXEmacs.
   Copyright (C) 1985-1988, 1992-1995 Free Software Foundation, Inc.
   Copyright (C) 1996 Ben Wing.

This file is part of SXEmacs

SXEmacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

SXEmacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>. */


/* Synched up with: Mule 2.0, FSF 19.30. */
/* More syncing: FSF Emacs 19.34.6 by Marc Paquette <marcpa@cam.org> */

#include <config.h>
#include "lisp.h"

#include "buffer.h"
#include "events/events.h"
#include "ui/frame.h"
#include "ui/insdel.h"
#include "lstream.h"
#include "ui/redisplay.h"
#include "sysdep.h"
#include "ui/window.h"          /* minibuf_level */
#ifdef FILE_CODING
#include "mule/file-coding.h"
#endif

#ifdef HAVE_LIBGEN_H            /* Must come before sysfile.h */
#include <libgen.h>
#endif
#include "sysfile.h"
#include "sysproc.h"
#include "syspwd.h"
#include "systime.h"
#include "sysdir.h"

#ifdef HPUX
#include <netio.h>
#ifdef HPUX_PRE_8_0
#include <errnet.h>
#endif                          /* HPUX_PRE_8_0 */
#endif                          /* HPUX */

int lisp_to_time(Lisp_Object, time_t *);
Lisp_Object time_to_lisp(time_t);

/* Nonzero during writing of auto-save files */
static int auto_saving;

/* Set by auto_save_1 to mode of original file so Fwrite_region_internal
   will create a new file with the same mode as the original */
static int auto_save_mode_bits;

/* Alist of elements (REGEXP . HANDLER) for file names
   whose I/O is done with a special handler.  */
Lisp_Object Vfile_name_handler_alist;

/* Format for auto-save files */
Lisp_Object Vauto_save_file_format;

/* Lisp functions for translating file formats */
Lisp_Object Qformat_decode, Qformat_annotate_function;

/* Functions to be called to process text properties in inserted file.  */
Lisp_Object Vafter_insert_file_functions;

/* Functions to be called to create text property annotations for file.  */
Lisp_Object Vwrite_region_annotate_functions;

/* During build_annotations, each time an annotation function is called,
   this holds the annotations made by the previous functions.  */
Lisp_Object Vwrite_region_annotations_so_far;

/* File name in which we write a list of all our auto save files.  */
Lisp_Object Vauto_save_list_file_name;

/* Prefix used to construct Vauto_save_list_file_name. */
Lisp_Object Vauto_save_list_file_prefix;

/* When non-nil, it prevents auto-save list file creation. */
int inhibit_auto_save_session;

int disable_auto_save_when_buffer_shrinks;

Lisp_Object Vdirectory_sep_char;

/* These variables describe handlers that have "already" had a chance
   to handle the current operation.

   Vinhibit_file_name_handlers is a list of file name handlers.
   Vinhibit_file_name_operation is the operation being handled.
   If we try to handle that operation, we ignore those handlers.  */

static Lisp_Object Vinhibit_file_name_handlers;
static Lisp_Object Vinhibit_file_name_operation;

Lisp_Object Qfile_error, Qfile_already_exists;

Lisp_Object Qauto_save_hook;
Lisp_Object Qauto_save_error;
Lisp_Object Qauto_saving;

Lisp_Object Qcar_less_than_car;

Lisp_Object Qcompute_buffer_file_truename;

EXFUN(Frunning_temacs_p, 0);

/* signal a file error when errno contains a meaningful value. */

DOESNT_RETURN report_file_error(const char *string, Lisp_Object data)
{
        /* #### dmoore - This uses current_buffer, better make sure no one
           has GC'd the current buffer.  File handlers are giving me a headache
           maybe I'll just always protect current_buffer around all of those
           calls. */

        signal_error(Qfile_error,
                     Fcons(build_translated_string(string),
                           Fcons(lisp_strerror(errno), data)));
}

void
maybe_report_file_error(const char *string, Lisp_Object data,
                        Lisp_Object class, Error_behavior errb)
{
        /* Optimization: */
        if (ERRB_EQ(errb, ERROR_ME_NOT))
                return;

        maybe_signal_error(Qfile_error,
                           Fcons(build_translated_string(string),
                                 Fcons(lisp_strerror(errno), data)),
                           class, errb);
}

/* signal a file error when errno does not contain a meaningful value. */

DOESNT_RETURN signal_file_error(const char *string, Lisp_Object data)
{
        signal_error(Qfile_error, list2(build_translated_string(string), data));
}

void
maybe_signal_file_error(const char *string, Lisp_Object data,
                        Lisp_Object class, Error_behavior errb)
{
        /* Optimization: */
        if (ERRB_EQ(errb, ERROR_ME_NOT))
                return;
        maybe_signal_error(Qfile_error,
                           list2(build_translated_string(string), data),
                           class, errb);
}

DOESNT_RETURN
signal_double_file_error(const char *string1, const char *string2,
                         Lisp_Object data)
{
        signal_error(Qfile_error,
                     list3(build_translated_string(string1),
                           build_translated_string(string2), data));
}

void
maybe_signal_double_file_error(const char *string1, const char *string2,
                               Lisp_Object data, Lisp_Object class,
                               Error_behavior errb)
{
        /* Optimization: */
        if (ERRB_EQ(errb, ERROR_ME_NOT))
                return;
        maybe_signal_error(Qfile_error,
                           list3(build_translated_string(string1),
                                 build_translated_string(string2),
                                 data), class, errb);
}

DOESNT_RETURN
signal_double_file_error_2(const char *string1, const char *string2,
                           Lisp_Object data1, Lisp_Object data2)
{
        signal_error(Qfile_error,
                     list4(build_translated_string(string1),
                           build_translated_string(string2), data1, data2));
}

void
maybe_signal_double_file_error_2(const char *string1, const char *string2,
                                 Lisp_Object data1, Lisp_Object data2,
                                 Lisp_Object class, Error_behavior errb)
{
        /* Optimization: */
        if (ERRB_EQ(errb, ERROR_ME_NOT))
                return;
        maybe_signal_error(Qfile_error,
                           list4(build_translated_string(string1),
                                 build_translated_string(string2),
                                 data1, data2), class, errb);
}
\f
/* Just like strerror(3), except return a lisp string instead of char *.
   The string needs to be converted since it may be localized.
   Perhaps this should use strerror-coding-system instead? */
Lisp_Object lisp_strerror(int errnum)
{
        return build_ext_string(strerror(errnum), Qnative);
}

static Lisp_Object close_file_unwind(Lisp_Object fd)
{
        if (CONSP(fd)) {
                if (INTP(XCAR(fd)))
                        close(XINT(XCAR(fd)));

                free_cons(XCONS(fd));
        } else
                close(XINT(fd));

        return Qnil;
}

static Lisp_Object delete_stream_unwind(Lisp_Object stream)
{
        Lstream_delete(XLSTREAM(stream));
        return Qnil;
}

/* Restore point, having saved it as a marker.  */

static Lisp_Object restore_point_unwind(Lisp_Object point_marker)
{
        BUF_SET_PT(current_buffer, marker_position(point_marker));
        return Fset_marker(point_marker, Qnil, Qnil);
}

/* Versions of read() and write() that allow quitting out of the actual
   I/O.  We don't use immediate_quit (i.e. direct longjmp() out of the
   signal handler) because that's way too losing.

   (#### Actually, longjmp()ing out of the signal handler may not be
   as losing as I thought.  See sys_do_signal() in sysdep.c.) */

ssize_t read_allowing_quit(int fildes, void *buf, size_t size)
{
        QUIT;
        return sys_read_1(fildes, buf, size, 1);
}

ssize_t write_allowing_quit(int fildes, const void *buf, size_t size)
{
        QUIT;
        return sys_write_1(fildes, buf, size, 1);
}
\f
Lisp_Object Qexpand_file_name;
Lisp_Object Qfile_truename;
Lisp_Object Qsubstitute_in_file_name;
Lisp_Object Qdirectory_file_name;
Lisp_Object Qfile_dirname;
Lisp_Object Qfile_basename;
Lisp_Object Qfile_name_directory;
Lisp_Object Qfile_name_nondirectory;
Lisp_Object Qunhandled_file_name_directory;
Lisp_Object Qfile_name_as_directory;
Lisp_Object Qcopy_file;
Lisp_Object Qmake_directory_internal;
Lisp_Object Qdelete_directory;
Lisp_Object Qdelete_file;
Lisp_Object Qrename_file;
Lisp_Object Qadd_name_to_file;
Lisp_Object Qmake_symbolic_link;
Lisp_Object Qfile_exists_p;
Lisp_Object Qfile_executable_p;
Lisp_Object Qfile_readable_p;
Lisp_Object Qfile_symlink_p;
Lisp_Object Qfile_writable_p;
Lisp_Object Qfile_directory_p;
Lisp_Object Qfile_regular_p;
Lisp_Object Qfile_accessible_directory_p;
Lisp_Object Qfile_modes;
Lisp_Object Qset_file_modes;
Lisp_Object Qfile_newer_than_file_p;
Lisp_Object Qinsert_file_contents;
Lisp_Object Qwrite_region;
Lisp_Object Qverify_visited_file_modtime;
Lisp_Object Qset_visited_file_modtime;

/* If FILENAME is handled specially on account of its syntax,
   return its handler function.  Otherwise, return nil.  */

DEFUN("find-file-name-handler", Ffind_file_name_handler, 1, 2, 0,       /*
Return FILENAME's handler function for OPERATION, if it has one.
Otherwise, return nil.
A file name is handled if one of the regular expressions in
`file-name-handler-alist' matches it.

If OPERATION equals `inhibit-file-name-operation', then we ignore
any handlers that are members of `inhibit-file-name-handlers',
but we still do run any other handlers.  This lets handlers
use the standard functions without calling themselves recursively.

Otherwise, OPERATION is the name of a funcall'able function.
*/
      (filename, operation))
{
        /* This function does not GC */
        /* This function can be called during GC */
        /* This function must not munge the match data.  */
        Lisp_Object chain, inhibited_handlers;

        CHECK_STRING(filename);

        if (EQ(operation, Vinhibit_file_name_operation))
                inhibited_handlers = Vinhibit_file_name_handlers;
        else
                inhibited_handlers = Qnil;

        EXTERNAL_LIST_LOOP(chain, Vfile_name_handler_alist) {
                Lisp_Object elt = XCAR(chain);
                if (CONSP(elt)) {
                        Lisp_Object string = XCAR(elt);
                        if (STRINGP(string)
                            && (fast_lisp_string_match(string, filename) >= 0)) {
                                Lisp_Object handler = XCDR(elt);
                                if (NILP(Fmemq(handler, inhibited_handlers)))
                                        return handler;
                        }
                }
                QUIT;
        }
        return Qnil;
}

static Lisp_Object
call2_check_string(Lisp_Object fn, Lisp_Object arg0, Lisp_Object arg1)
{
        /* This function can call lisp */
        Lisp_Object result = call2(fn, arg0, arg1);
        CHECK_STRING(result);
        return result;
}

static Lisp_Object
call2_check_string_or_nil(Lisp_Object fn, Lisp_Object arg0, Lisp_Object arg1)
{
        /* This function can call lisp */
        Lisp_Object result = call2(fn, arg0, arg1);
        if (!NILP(result))
                CHECK_STRING(result);
        return result;
}

static Lisp_Object
call3_check_string(Lisp_Object fn, Lisp_Object arg0,
                   Lisp_Object arg1, Lisp_Object arg2)
{
        /* This function can call lisp */
        Lisp_Object result = call3(fn, arg0, arg1, arg2);
        CHECK_STRING(result);
        return result;
}
\f
DEFUN("file-name-directory", Ffile_name_directory, 1, 1, 0,     /*
Return the directory component in file name FILENAME.
Return nil if FILENAME does not include a directory.
Otherwise return a directory spec.
Given a Unix syntax file name, returns a string ending in slash.
*/
      (filename))
{
        /* This function can GC.  GC checked 2000-07-28 ben */
        Bufbyte *beg;
        Bufbyte *p;
        Lisp_Object handler;

        CHECK_STRING(filename);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(filename, Qfile_name_directory);
        if (!NILP(handler))
                return call2_check_string_or_nil(handler, Qfile_name_directory,
                                                 filename);

#ifdef FILE_SYSTEM_CASE
        filename = FILE_SYSTEM_CASE(filename);
#endif
        beg = XSTRING_DATA(filename);
        p = beg + XSTRING_LENGTH(filename);

        while (p != beg && !IS_ANY_SEP(p[-1])
            )
                p--;

        if (p == beg)
                return Qnil;
        return make_string(beg, p - beg);
}

DEFUN("file-name-nondirectory", Ffile_name_nondirectory, 1, 1, 0,       /*
Return file name FILENAME sans its directory.
For example, in a Unix-syntax file name,
this is everything after the last slash,
or the entire name if it contains no slash.
*/
      (filename))
{
        /* This function can GC.  GC checked 2000-07-28 ben */
        Bufbyte *beg, *p, *end;
        Lisp_Object handler;

        CHECK_STRING(filename);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(filename, Qfile_name_nondirectory);
        if (!NILP(handler))
                return call2_check_string(handler, Qfile_name_nondirectory,
                                          filename);

        beg = XSTRING_DATA(filename);
        end = p = beg + XSTRING_LENGTH(filename);

        while (p != beg && !IS_ANY_SEP(p[-1])
            )
                p--;

        return make_string(p, end - p);
}


static
Bytecount file_basename_match_extension(Lisp_Object filename,
                                        Lisp_Object extension)
{
        Bytecount match = -1;
        Bytecount len = XSTRING_LENGTH( extension );
        if ( len > 0 ) {
                char     re[len+6],
                        *rep = re;
                Bufbyte *ext = XSTRING_DATA(extension);
                Lisp_Object regexp;

                memset(re,0,len+6);
                if ( strncmp( (char*)ext, "\\.", 2 ) != 0 ) {
                        strncpy(rep, "\\.", 3);
                        rep += 2;
                }
                memcpy(rep,ext,len);
                /* Note that we advance by len-1 to be positioned at
                   the last char of extension so that we can check it
                   for '$' on the if statement and advance to the
                   terminator if need to append...
                */
                rep += len-1;
                if ( *rep++ != '$' )
                        *rep++ = '$';
                *rep = '\0';
                regexp = make_string( (Bufbyte*)re, strlen(re));
                match = fast_lisp_string_match( regexp, filename );
        }
        return match;
}

DEFUN("file-basename", Ffile_basename, 1, 2, 0, /*
Return the basename of FILENAME sans its base directory.
If EXTENSION is non-nil the extension is also removed if it matches the regexp.
EXTENSION can be a list of regexps.
For example, in a Unix-syntax file name,
this is everything after the last slash,
or the entire name if it contains no slash.
It ignores trailing slash.
*/
      (filename, extension))
{
        /* This function can GC.  GC checked 2000-07-28 ben */
        Bufbyte *beg, *p, *end;
        Lisp_Object handler;
        Lisp_Object rest;
        Lisp_Object ext;
        Lisp_Object res;
        struct gcpro gcpro1, gcpro2, gcpro3, gcpro4;

        CHECK_STRING(filename);
        if ( ! NILP(extension) && ! STRINGP(extension) &&
             ! LISTP(extension) )
                dead_wrong_type_argument(Qstringp, extension);

        GCPRO4(handler,res,rest,ext);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(filename, Qfile_basename);
        if (!NILP(handler))
                return call2_check_string(handler, Qfile_basename,
                                          filename);

        beg = XSTRING_DATA(filename);
        end = p = beg + XSTRING_LENGTH(filename);
        if ( IS_ANY_SEP(p[-1]) ) {
          p--;
          end--;
        }
        while (p != beg && !IS_ANY_SEP(p[-1]))
                p--;

        res = make_string(p, end - p);
        if ( STRINGP( extension ) ) {
                Bytecount match;
                match = file_basename_match_extension(res,
                                                      extension);
                if ( match >= 0 )
                        RETURN_UNGCPRO(make_string(p, match));
        } else if ( ! NILP(extension) && LISTP( extension ) ) {
                rest = extension;
                do {
                        ext = XCAR(rest);
                        Bytecount match;
                        match = file_basename_match_extension(res,
                                                              ext);
                        if ( match >= 0 )
                                RETURN_UNGCPRO(make_string(p, match));
                        rest = XCDR(rest);
                } while( ! NILP(rest) );
        }
        RETURN_UNGCPRO(res);
}


DEFUN("file-dirname", Ffile_dirname, 1, 1, 0,   /*
Return the directory component in file name FILENAME.
Return nil if FILENAME does not include a directory.
Otherwise return a directory spec.
Given a Unix syntax file name, returns a string ending in slash.
It ignores the trailing slash in FILENAME.
*/
      (filename))
{
        /* This function can GC.  GC checked 2000-07-28 ben */
        Bufbyte *beg, *p, *end;
        Lisp_Object handler;

        CHECK_STRING(filename);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(filename, Qfile_dirname);
        if (!NILP(handler))
                return call2_check_string_or_nil(handler, Qfile_dirname,
                                                 filename);

        beg = XSTRING_DATA(filename);
        end = p = beg + XSTRING_LENGTH(filename);
        if ( IS_ANY_SEP(p[-1]) ) {
          p--;
          end--;
        }
        while (p != beg && !IS_ANY_SEP(p[-1])
               )
                p--;

        if ( beg == p )
          return Qnil;
        return make_string(beg, p-beg);
}


DEFUN("unhandled-file-name-directory", Funhandled_file_name_directory, 1, 1, 0, /*
Return a directly usable directory name somehow associated with FILENAME.
A `directly usable' directory name is one that may be used without the
intervention of any file handler.
If FILENAME is a directly usable file itself, return
\(file-name-directory FILENAME).
The `call-process' and `start-process' functions use this function to
get a current directory to run processes in.
*/
      (filename))
{
        /* This function can GC.  GC checked 2000-07-28 ben */
        Lisp_Object handler;

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler =
            Ffind_file_name_handler(filename, Qunhandled_file_name_directory);
        if (!NILP(handler))
                return call2(handler, Qunhandled_file_name_directory, filename);

        return Ffile_name_directory(filename);
}
\f
static char *file_name_as_directory(char *out, const char *in, size_t len)
{
        /* This function cannot GC */
        int size = strlen(in);

        if (size == 0) {
                assert(len >= 3);
                out[0] = '.';
                out[1] = DIRECTORY_SEP;
                out[2] = '\0';
        } else {
                xstrncpy(out, in, len);
                /* Append a slash if necessary */
                if (!IS_ANY_SEP(out[size - 1])) {
                        out[size] = DIRECTORY_SEP;
                        out[size + 1] = '\0';
                }
        }
        return out;
}

DEFUN("file-name-as-directory", Ffile_name_as_directory, 1, 1, 0,       /*
Return a string representing file FILENAME interpreted as a directory.
This operation exists because a directory is also a file, but its name as
a directory is different from its name as a file.
The result can be used as the value of `default-directory'
or passed as second argument to `expand-file-name'.
For a Unix-syntax file name, just appends a slash,
except for (file-name-as-directory \"\") => \"./\".
*/
      (filename))
{
        /* This function can GC.  GC checked 2000-07-28 ben */
        size_t len = 0;
        char *buf = NULL;
        Lisp_Object handler = Qnil;

        CHECK_STRING(filename);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(filename, Qfile_name_as_directory);
        if (!NILP(handler))
                return call2_check_string(handler, Qfile_name_as_directory,
                                          filename);

        len = XSTRING_LENGTH(filename) + 10;
        buf = (char *)alloca(len);
        return build_string(file_name_as_directory
                            (buf, (char*)XSTRING_DATA(filename), len));
}
\f
/*
 * Convert from directory name to filename.
 * On UNIX, it's simple: just make sure there isn't a terminating /
 *
 * Value is nonzero if the string output is different from the input.
 */

static int directory_file_name(const char *src, char *dst, size_t len)
{
        /* This function cannot GC */
        long slen = strlen(src);
        /* Process as Unix format: just remove any final slash.
           But leave "/" unchanged; do not change it to "".  */
        xstrncpy(dst, src, len);
        if (slen > 1 && IS_DIRECTORY_SEP(dst[slen - 1])
            )
                dst[slen - 1] = 0;
        return 1;
}

DEFUN("directory-file-name", Fdirectory_file_name, 1, 1, 0,     /*
Return the file name of the directory named DIRECTORY.
This is the name of the file that holds the data for the directory.
This operation exists because a directory is also a file, but its name as
a directory is different from its name as a file.
In Unix-syntax, this function just removes the final slash.
*/
      (directory))
{
        /* This function can GC.  GC checked 2000-07-28 ben */
        size_t len = 0;
        char *buf = NULL;
        Lisp_Object handler;

        CHECK_STRING(directory);

#if 0                           /* #### WTF? */
        if (NILP(directory))
                return Qnil;
#endif

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(directory, Qdirectory_file_name);
        if (!NILP(handler))
                return call2_check_string(handler, Qdirectory_file_name,
                                          directory);
        len = XSTRING_LENGTH(directory) + 20;
        buf = (char *)alloca(len);
        directory_file_name((char *)XSTRING_DATA(directory), buf, len);
        return build_string(buf);
}
\f
/* Fmake_temp_name used to be a simple wrapper around mktemp(), but it
   proved too broken for our purposes (it supported only 26 or 62
   unique names under some implementations).  For example, this
   arbitrary limit broke generation of Gnus Incoming* files.

   This implementation is better than what one usually finds in libc.
   --hniksic */

static unsigned int temp_name_rand;

DEFUN("make-temp-name", Fmake_temp_name, 1, 1, 0,       /*
Generate a temporary file name starting with PREFIX.
The Emacs process number forms part of the result, so there is no
danger of generating a name being used by another process.

In addition, this function makes an attempt to choose a name that
does not specify an existing file.  To make this work, PREFIX should
be an absolute file name.
*/
      (prefix))
{
        static const char tbl[64] = {
                'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
                'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
                'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
                'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
                'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
                'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
                'w', 'x', 'y', 'z', '0', '1', '2', '3',
                '4', '5', '6', '7', '8', '9', '-', '_'
        };

        Lisp_Object val;
        Bytecount len;
        Bufbyte *p, *data;

        CHECK_STRING(prefix);

        /* I was tempted to apply Fexpand_file_name on PREFIX here, but it's
           a bad idea because:

           1) It might change the prefix, so the resulting string might not
           begin with PREFIX.  This violates the principle of least
           surprise.

           2) It breaks under many unforeseeable circumstances, such as with
           the code that uses (make-temp-name "") instead of
           (make-temp-name "./").

           3) It might yield unexpected (to stat(2)) results in the presence
           of EFS and file name handlers.  */

        len = XSTRING_LENGTH(prefix);
        val = make_uninit_string(len + 6);
        data = XSTRING_DATA(val);
        memcpy(data, XSTRING_DATA(prefix), len);
        p = data + len;

        /* VAL is created by adding 6 characters to PREFIX.  The first three
           are the PID of this process, in base 64, and the second three are
           a pseudo-random number seeded from process startup time.  This
           ensures 262144 unique file names per PID per PREFIX per machine.  */

        {
                unsigned int pid = (unsigned int)getpid();
                *p++ = tbl[(pid >> 0) & 63];
                *p++ = tbl[(pid >> 6) & 63];
                *p++ = tbl[(pid >> 12) & 63];
        }

        /* Here we try to minimize useless stat'ing when this function is
           invoked many times successively with the same PREFIX.  We achieve
           this by using a very pseudo-random number generator to generate
           file names unique to this process, with a very long cycle. */

        while (1) {
                struct stat ignored;

                p[0] = tbl[(temp_name_rand >> 0) & 63];
                p[1] = tbl[(temp_name_rand >> 6) & 63];
                p[2] = tbl[(temp_name_rand >> 12) & 63];

                /* Poor man's congruential RN generator.  Replace with ++count
                   for debugging.  */
                temp_name_rand += 25229;
                temp_name_rand %= 225307;

                QUIT;

                if (sxemacs_stat((const char *)data, &ignored) < 0) {
                        /* We want to return only if errno is ENOENT.  */
                        if (errno == ENOENT)
                                return val;

                        /* The error here is dubious, but there is little else we
                           can do.  The alternatives are to return nil, which is
                           as bad as (and in many cases worse than) throwing the
                           error, or to ignore the error, which will likely result
                           in inflooping.  */
                        report_file_error
                            ("Cannot create temporary name for prefix",
                             list1(prefix));
                        return Qnil;    /* not reached */
                }
        }
}
\f
DEFUN("expand-file-name", Fexpand_file_name, 1, 2, 0,   /*
Convert filename NAME to absolute, and canonicalize it.
Second arg DEFAULT-DIRECTORY is directory to start with if NAME is relative
(does not start with slash); if DEFAULT-DIRECTORY is nil or missing,
the current buffer's value of `default-directory' is used.
File name components that are `.' are removed, and
so are file name components followed by `..', along with the `..' itself;
note that these simplifications are done without checking the resulting
file names in the file system.
An initial `~/' expands to your home directory.
An initial `~USER/' expands to USER's home directory.
See also the function `substitute-in-file-name'.
*/
      (name, default_directory))
{
        /* This function can GC.  GC-checked 2000-11-18 */
        Bufbyte *nm;

        Bufbyte *newdir, *p, *o;
        int tlen;
        Bufbyte *target;
        struct passwd *pw;
        int length;
        Lisp_Object handler = Qnil;
        struct gcpro gcpro1, gcpro2, gcpro3;

        /* both of these get set below */
        GCPRO3(name, default_directory, handler);

        CHECK_STRING(name);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(name, Qexpand_file_name);
        if (!NILP(handler))
                RETURN_UNGCPRO(call3_check_string(handler, Qexpand_file_name,
                                                  name, default_directory));

        /* Use the buffer's default-directory if DEFAULT_DIRECTORY is omitted.  */
        if (NILP(default_directory))
                default_directory = current_buffer->directory;
        if (!STRINGP(default_directory))
                default_directory = build_string("/");

        if (!NILP(default_directory)) {
                handler =
                    Ffind_file_name_handler(default_directory,
                                            Qexpand_file_name);
                if (!NILP(handler))
                        RETURN_UNGCPRO(call3(handler, Qexpand_file_name,
                                             name, default_directory));
        }

        o = XSTRING_DATA(default_directory);

        /* Make sure DEFAULT_DIRECTORY is properly expanded.
           It would be better to do this down below where we actually use
           default_directory.  Unfortunately, calling Fexpand_file_name recursively
           could invoke GC, and the strings might be relocated.  This would
           be annoying because we have pointers into strings lying around
           that would need adjusting, and people would add new pointers to
           the code and forget to adjust them, resulting in intermittent bugs.
           Putting this call here avoids all that crud.

           The EQ test avoids infinite recursion.  */
        if (!NILP(default_directory) && !EQ(default_directory, name)
            /* Save time in some common cases - as long as default_directory
               is not relative, it can be canonicalized with name below (if it
               is needed at all) without requiring it to be expanded now.  */
            /* Detect Unix absolute file names (/... alone is not absolute on
               Windows).  */
            && !(IS_DIRECTORY_SEP(o[0]))
            )

                default_directory = Fexpand_file_name(default_directory, Qnil);

#ifdef FILE_SYSTEM_CASE
        name = FILE_SYSTEM_CASE(name);
#endif

        /* #### dmoore - this is ugly, clean this up.  Looks like nm pointing
           into name should be safe during all of this, though. */
        nm = XSTRING_DATA(name);

        /* If nm is absolute, look for /./ or /../ sequences; if none are
           found, we can probably return right away.  We will avoid allocating
           a new string if name is already fully expanded.  */
        if (IS_DIRECTORY_SEP(nm[0])) {
                /* If it turns out that the filename we want to return is just a
                   suffix of FILENAME, we don't need to go through and edit
                   things; we just need to construct a new string using data
                   starting at the middle of FILENAME.  If we set lose to a
                   non-zero value, that means we've discovered that we can't do
                   that cool trick.  */
                int lose = 0;

                p = nm;
                while (*p) {
                        /* Since we know the name is absolute, we can assume
                           that each element starts with a "/".  */

                        /* "." and ".." are hairy.  */
                        if (IS_DIRECTORY_SEP(p[0])
                            && p[1] == '.' && (IS_DIRECTORY_SEP(p[2])
                                               || p[2] == 0
                                               || (p[2] == '.'
                                                   && (IS_DIRECTORY_SEP(p[3])
                                                       || p[3] == 0)))) {
                                lose = 1;
                        }
                        p++;
                }
                if (!lose) {
                        if (nm == XSTRING_DATA(name)) {
                                RETURN_UNGCPRO(name);
                        }
                        RETURN_UNGCPRO(build_string((char*)nm));
                }
        }

        /* At this point, nm might or might not be an absolute file name.  We
           need to expand ~ or ~user if present, otherwise prefix nm with
           default_directory if nm is not absolute, and finally collapse /./
           and /foo/../ sequences.

           We set newdir to be the appropriate prefix if one is needed:
           - the relevant user directory if nm starts with ~ or ~user
           - the specified drive's working dir (DOS/NT only) if nm does not
           start with /
           - the value of default_directory.

           Note that these prefixes are not guaranteed to be absolute (except
           for the working dir of a drive).  Therefore, to ensure we always
           return an absolute name, if the final prefix is not absolute we
           append it to the current working directory.  */

        newdir = 0;

        if (nm[0] == '~') {     /* prefix ~ */
                if (IS_DIRECTORY_SEP(nm[1]) || nm[1] == 0) {
                        /* ~ by itself */
                        Extbyte *newdir_external = get_home_directory();

                        if (newdir_external == NULL) {
                                newdir = (Bufbyte *) "";
                        } else {
                                /* aint that a bit weird just to get the
                                 * signedness correct? */
                                Extbyte *newdir_cpy = (Extbyte*)newdir;
                                TO_INTERNAL_FORMAT(
                                        C_STRING, newdir_external,
                                        C_STRING_ALLOCA,
                                        newdir_cpy,
                                        Qfile_name);
                                newdir = (Bufbyte*)newdir_cpy;
                        }
                        nm++;
                } else {        /* ~user/filename */

                        for (p = nm; *p && (!IS_DIRECTORY_SEP(*p)); p++)
                                DO_NOTHING;
                        o = (Bufbyte *) alloca(p - nm + 1);
                        memcpy(o, (char *)nm, p - nm);
                        o[p - nm] = 0;

                        /* #### While NT is single-user (for the moment) you still
                           can have multiple user profiles users defined, each with
                           its HOME.  So maybe possibly we should think about handling
                           ~user. --ben */
                                /* Jamie reports that getpwnam() can get wedged
                                   by SIGIO/SIGALARM occurring in it. (It can call
                                   select()). */
                                slow_down_interrupts();
                                pw = (struct passwd *)getpwnam((char *)o + 1);
                                speed_up_interrupts();
                                if (pw) {
                                        newdir = (Bufbyte *) pw->pw_dir;
                                        nm = p;
                                }

                        /* If we don't find a user of that name, leave the name
                           unchanged; don't move nm forward to p.  */
                }
        }

        /* Finally, if no prefix has been specified and nm is not absolute,
           then it must be expanded relative to default_directory. */

        if (1
            /* /... alone is not absolute on DOS and Windows. */
            && !IS_DIRECTORY_SEP(nm[0])
            && !newdir) {
                newdir = XSTRING_DATA(default_directory);
        }

        if (newdir) {
                /* Get rid of any slash at the end of newdir, unless newdir is
                   just // (an incomplete UNC name).  */
                length = strlen((char *)newdir);
                if (length > 1 && IS_DIRECTORY_SEP(newdir[length - 1])) {
                        Bufbyte *temp = (Bufbyte *) alloca(length);
                        memcpy(temp, newdir, length - 1);
                        temp[length - 1] = 0;
                        newdir = temp;
                }
                tlen = length + 1;
        } else
                tlen = 0;

        /* Now concatenate the directory and name to new space in the stack frame */
        tlen += strlen((char *)nm) + 1;
        target = (Bufbyte *) alloca(tlen);
        *target = 0;

        if (newdir) {
                if (nm[0] == 0 || IS_DIRECTORY_SEP(nm[0]))
                        xstrncpy((char *)target, (char *)newdir, tlen);
                else
                        file_name_as_directory((char *)target, (char *)newdir, tlen);
        }

        xstrncat((char *)target, (char *)nm, tlen-1);

        /* ASSERT (IS_DIRECTORY_SEP (target[0])) if not VMS */

        /* Now canonicalize by removing /. and /foo/.. if they appear.  */

        p = target;
        o = target;

        while (*p) {
                if (!IS_DIRECTORY_SEP(*p)) {
                        *o++ = *p++;
                } else if (IS_DIRECTORY_SEP(p[0])
                           && p[1] == '.' && (IS_DIRECTORY_SEP(p[2])
                                              || p[2] == 0)) {
                        /* If "/." is the entire filename, keep the "/".  Otherwise,
                           just delete the whole "/.".  */
                        if (o == target && p[2] == '\0')
                                *o++ = *p;
                        p += 2;
                } else if (IS_DIRECTORY_SEP(p[0]) && p[1] == '.' && p[2] == '.'
                           /* `/../' is the "superroot" on certain file systems.  */
                           && o != target
                           && (IS_DIRECTORY_SEP(p[3]) || p[3] == 0)) {
                        while (o != target && (--o) && !IS_DIRECTORY_SEP(*o)) ;
                        /* Keep initial / only if this is the whole name.  */
                        if (o == target && IS_ANY_SEP(*o) && p[3] == 0)
                                ++o;
                        p += 3;
                }
                else {
                        *o++ = *p++;
                }
        }

        RETURN_UNGCPRO(make_string(target, o - target));
}

DEFUN("file-truename", Ffile_truename, 1, 2, 0, /*
Return the canonical name of FILENAME.
Second arg DEFAULT is directory to start with if FILENAME is relative
(does not start with slash); if DEFAULT is nil or missing,
the current buffer's value of `default-directory' is used.
No component of the resulting pathname will be a symbolic link, as
in the realpath() function.
*/
      (filename, default_))
{
        /* This function can GC.  GC checked 2000-07-28 ben. */
        Lisp_Object expanded_name;
        struct gcpro gcpro1;

        CHECK_STRING(filename);

        expanded_name = Fexpand_file_name(filename, default_);

        if (!STRINGP(expanded_name))
                return Qnil;

        GCPRO1(expanded_name);

        {
                Lisp_Object handler =
                        Ffind_file_name_handler(expanded_name, Qfile_truename);

                if (!NILP(handler))
                        RETURN_UNGCPRO
                                (call2_check_string
                                 (handler, Qfile_truename, expanded_name));
        }

        {
                char resolved_path[MAXPATHLEN];
                Extbyte *path = NULL;
                Extbyte *p = NULL;
                Extcount elen;

                TO_EXTERNAL_FORMAT(LISP_STRING, expanded_name,
                                   ALLOCA, (path, elen), Qfile_name);
                p = path;

                if (elen > MAXPATHLEN)
                        goto toolong;

                /* Try doing it all at once. */
                /* !! Does realpath() Mule-encapsulate?  Answer: Nope!
                   So we do it above */
                if (path != NULL && !xrealpath((char *)path, resolved_path)) {
                        /* Didn't resolve it -- have to do it one
                           component at a time.

                           "realpath" is a typically useless, stupid
                           un*x piece of crap.  It claims to return a
                           useful value in the "error" case, but since
                           there is no indication provided of how far
                           along the pathname the function went before
                           erring, there is no way to use the partial
                           result returned.  What a piece of junk.

                           The above comment refers to historical
                           versions of realpath().  The Unix98 specs
                           state:

                           "On successful completion, realpath()
                           returns a pointer to the resolved
                           name. Otherwise, realpath() returns a null
                           pointer and sets errno to indicate the
                           error, and the contents of the buffer
                           pointed to by resolved_name are undefined."

                           Since we depend on undocumented semantics
                           of various system realpath()s, we just use
                           our own version in realpath.c.
                        */
                        for (;;) {
                                Extbyte *pos = NULL;

                                for (pos = p + 1; pos < path + elen; pos++) {
                                        if (IS_DIRECTORY_SEP(*pos)) {
                                                *(p = pos) = 0;
                                                break;
                                        }
                                }
                                if (p != pos)
                                        p = 0;

                                if (xrealpath((char *)path, resolved_path)) {
                                        if (p)
                                                *p = DIRECTORY_SEP;
                                        else
                                                break;

                                } else if (errno == ENOENT || errno == EACCES) {
                                        /* Failed on this component.
                                           Just tack on the rest of
                                           the string and we are
                                           done. */
                                        int rlen = strlen(resolved_path);

                                        /* "On failure, it returns
                                           NULL, sets errno to
                                           indicate the error, and
                                           places in resolved_path the
                                           absolute pathname of the
                                           path component which could
                                           not be resolved."
                                        */
                                        if (p == NULL ) {
                                                break;
                                        }
                                        int plen = elen - (p - path);

                                        if (rlen > 1 &&
                                            IS_DIRECTORY_SEP
                                            (resolved_path[rlen - 1]))
                                                rlen = rlen - 1;

                                        if ((plen + rlen + 1) >
                                            countof(resolved_path))
                                                goto toolong;

                                        resolved_path[rlen] = DIRECTORY_SEP;
                                        memcpy(resolved_path + rlen + 1,
                                               p + 1, plen + 1 - 1);
                                        break;
                                } else
                                        goto lose;
                        }
                }

                {
                        Lisp_Object resolved_name;
                        int rlen = strlen(resolved_path);

                        if (elen > 0
                            && IS_DIRECTORY_SEP(
                                    XSTRING_BYTE(expanded_name, elen-1))
                            && !(rlen > 0 &&
                                 IS_DIRECTORY_SEP(resolved_path[rlen-1]))) {
                                if (rlen + 1 > countof(resolved_path))
                                        goto toolong;
                                resolved_path[rlen++] = DIRECTORY_SEP;
                                resolved_path[rlen] = '\0';
                        }
                        TO_INTERNAL_FORMAT(DATA, (resolved_path, rlen),
                                           LISP_STRING, resolved_name,
                                           Qfile_name);
                        RETURN_UNGCPRO(resolved_name);
                }

        toolong:
                errno = ENAMETOOLONG;
                goto lose;
        lose:
                report_file_error("Finding truename", list1(expanded_name));
        }
        RETURN_UNGCPRO(Qnil);
}
\f
DEFUN("substitute-in-file-name", Fsubstitute_in_file_name, 1, 1, 0,     /*
Substitute environment variables referred to in FILENAME.
`$FOO' where FOO is an environment variable name means to substitute
the value of that variable.  The variable name should be terminated
with a character, not a letter, digit or underscore; otherwise, enclose
the entire variable name in braces.
If `/~' appears, all of FILENAME through that `/' is discarded.
*/
      (filename))
{
        /* This function can GC.  GC checked 2000-07-28 ben. */
        Bufbyte *nm;

        Bufbyte *s, *p, *o, *x, *endp;
        Bufbyte *target = 0;
        int total = 0;
        int substituted = 0;
        size_t avail = 0;
        Bufbyte *xnm;
        Lisp_Object handler;

        CHECK_STRING(filename);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(filename, Qsubstitute_in_file_name);
        if (!NILP(handler))
                return call2_check_string_or_nil(handler,
                                                 Qsubstitute_in_file_name,
                                                 filename);

        nm = XSTRING_DATA(filename);
        endp = nm + XSTRING_LENGTH(filename);

        /* If /~ or // appears, discard everything through first slash. */

        for (p = nm; p != endp; p++) {
                if ((p[0] == '~'
                     || IS_DIRECTORY_SEP(p[0])
                    )
                    && p != nm && (IS_DIRECTORY_SEP(p[-1]))) {
                        nm = p;
                        substituted = 1;
                }
        }

        /* See if any variables are substituted into the string
           and find the total length of their values in `total' */

        for (p = nm; p != endp;)
                if (*p != '$')
                        p++;
                else {
                        p++;
                        if (p == endp)
                                goto badsubst;
                        else if (*p == '$') {
                                /* "$$" means a single "$" */
                                p++;
                                total -= 1;
                                substituted = 1;
                                continue;
                        } else if (*p == '{') {
                                o = ++p;
                                while (p != endp && *p != '}')
                                        p++;
                                if (*p != '}')
                                        goto missingclose;
                                s = p;
                        } else {
                                o = p;
                                while (p != endp && (isalnum(*p) || *p == '_'))
                                        p++;
                                s = p;
                        }

                        /* Copy out the variable name */
                        target = (Bufbyte *) alloca(s - o + 1);
                        strncpy((char *)target, (char *)o, s - o);
                        target[s - o] = '\0';

                        /* Get variable value */
                        o = (Bufbyte *) egetenv((char *)target);
                        if (!o)
                                goto badvar;
                        total += strlen((char *)o);
                        substituted = 1;
                }

        if (!substituted)
                return filename;

        /* If substitution required, recopy the filename and do it */
        /* Make space in stack frame for the new copy */
        avail = XSTRING_LENGTH(filename) + total + 1;
        xnm = (Bufbyte *) alloca(avail);
        x = xnm;

        /* Copy the rest of the name through, replacing $ constructs with values */
        for (p = nm; *p;)
                if (*p != '$') {
                        *x++ = *p++;
                        avail--;
                } else {
                        p++;
                        if (p == endp)
                                goto badsubst;
                        else if (*p == '$') {
                                *x++ = *p++;
                                avail--;
                                continue;
                        } else if (*p == '{') {
                                o = ++p;
                                while (p != endp && *p != '}')
                                        p++;
                                if (*p != '}')
                                        goto missingclose;
                                s = p++;
                        } else {
                                o = p;
                                while (p != endp && (isalnum(*p) || *p == '_'))
                                        p++;
                                s = p;
                        }

                        /* Copy out the variable name */
                        target = (Bufbyte *) alloca(s - o + 1);
                        strncpy((char *)target, (char *)o, s - o);
                        target[s - o] = '\0';

                        /* Get variable value */
                        o = (Bufbyte *) egetenv((char *)target);
                        if (!o)
                                goto badvar;

                        xstrncpy((char *)x, (char *)o, avail);
                        x += strlen((char *)o);
                        avail -= strlen((char *)o);
                }

        *x = 0;

        /* If /~ or // appears, discard everything through first slash. */

        for (p = xnm; p != x; p++)
                if ((p[0] == '~'
                     || IS_DIRECTORY_SEP(p[0])
                    )
                    /* don't do p[-1] if that would go off the beginning --jwz */
                    && p != nm && p > xnm && IS_DIRECTORY_SEP(p[-1]))
                        xnm = p;

        return make_string(xnm, x - xnm);

      badsubst:
        syntax_error("Bad format environment-variable substitution", filename);
      missingclose:
        syntax_error("Missing \"}\" in environment-variable substitution",
                     filename);
      badvar:
        syntax_error_2("Substituting nonexistent environment variable",
                       filename, build_string((char *)target));

        /* NOTREACHED */
        return Qnil;            /* suppress compiler warning */
}
\f
/* A slightly faster and more convenient way to get
   (directory-file-name (expand-file-name FOO)).  */

Lisp_Object expand_and_dir_to_file(Lisp_Object filename, Lisp_Object defdir)
{
        /* This function can call Lisp.  GC checked 2000-07-28 ben */
        Lisp_Object abspath;
        struct gcpro gcpro1;

        abspath = Fexpand_file_name(filename, defdir);
        GCPRO1(abspath);
        /* Remove final slash, if any (unless path is root).
           stat behaves differently depending!  */
        if (XSTRING_LENGTH(abspath) > 1
            &&
            IS_DIRECTORY_SEP(XSTRING_BYTE(abspath, XSTRING_LENGTH(abspath) - 1))
            &&
            !IS_DEVICE_SEP(XSTRING_BYTE(abspath, XSTRING_LENGTH(abspath) - 2)))
                /* We cannot take shortcuts; they might be wrong for magic file names.  */
                abspath = Fdirectory_file_name(abspath);
        UNGCPRO;
        return abspath;
}
\f
/* Signal an error if the file ABSNAME already exists.
   If INTERACTIVE is nonzero, ask the user whether to proceed,
   and bypass the error if the user says to go ahead.
   QUERYSTRING is a name for the action that is being considered
   to alter the file.
   *STATPTR is used to store the stat information if the file exists.
   If the file does not exist, STATPTR->st_mode is set to 0.  */

static void
barf_or_query_if_file_exists(Lisp_Object absname, const char *querystring,
                             int interactive, struct stat *statptr)
{
        /* This function can call Lisp.  GC checked 2000-07-28 ben */
        struct stat statbuf;

        /* stat is a good way to tell whether the file exists,
           regardless of what access permissions it has.  */
        if (sxemacs_stat((char *)XSTRING_DATA(absname), &statbuf) >= 0) {
                Lisp_Object tem;

                if (interactive) {
                        Lisp_Object prompt;
                        struct gcpro gcpro1;

                        prompt = emacs_doprnt_string_c
                            ((const Bufbyte *)
                             GETTEXT("File %s already exists; %s anyway? "),
                             Qnil, -1, XSTRING_DATA(absname),
                             GETTEXT(querystring));

                        GCPRO1(prompt);
                        tem = call1(Qyes_or_no_p, prompt);
                        UNGCPRO;
                } else
                        tem = Qnil;

                if (NILP(tem))
                        Fsignal(Qfile_already_exists,
                                list2(build_translated_string
                                      ("File already exists"), absname));
                if (statptr)
                        *statptr = statbuf;
        } else {
                if (statptr)
                        statptr->st_mode = 0;
        }
        return;
}

DEFUN("copy-file", Fcopy_file, 2, 4, "fCopy file: \nFCopy %s to file: \np\nP",  /*
Copy FILENAME to NEWNAME.  Both args must be strings.
Signals a `file-already-exists' error if file NEWNAME already exists,
unless a third argument OK-IF-ALREADY-EXISTS is supplied and non-nil.
A number as third arg means request confirmation if NEWNAME already exists.
This is what happens in interactive use with M-x.
Fourth arg KEEP-TIME non-nil means give the new file the same
last-modified time as the old one.  (This works on only some systems.)
A prefix arg makes KEEP-TIME non-nil.
*/
      (filename, newname, ok_if_already_exists, keep_time))
{
        /* This function can call Lisp.  GC checked 2000-07-28 ben */
        int ifd, ofd, n;
        char buf[16 * 1024];
        struct stat st, out_st;
        Lisp_Object handler;
        int speccount = specpdl_depth();
        struct gcpro gcpro1, gcpro2;
        /* Lisp_Object args[6]; */
        int input_file_statable_p;

        GCPRO2(filename, newname);
        CHECK_STRING(filename);
        CHECK_STRING(newname);
        filename = Fexpand_file_name(filename, Qnil);
        newname = Fexpand_file_name(newname, Qnil);

        /* If the input file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(filename, Qcopy_file);
        /* Likewise for output file name.  */
        if (NILP(handler))
                handler = Ffind_file_name_handler(newname, Qcopy_file);
        if (!NILP(handler)) {
                UNGCPRO;
                return call5(handler, Qcopy_file, filename, newname,
                             ok_if_already_exists, keep_time);
        }

        /* When second argument is a directory, copy the file into it.
           (copy-file "foo" "bar/") == (copy-file "foo" "bar/foo")
         */
        if (!NILP(Ffile_directory_p(newname))) {
                Lisp_Object args[3] = {newname, Qnil, Qnil};
                struct gcpro ngcpro1;
                int i = 1;

                NGCPROn(args, countof(args));
                if (!IS_DIRECTORY_SEP(
                            XSTRING_BYTE(newname,
                                         XSTRING_LENGTH(newname) - 1))) {
                        args[i++] = Fchar_to_string(Vdirectory_sep_char);
                }
                args[i++] = Ffile_name_nondirectory(filename);
                newname = Fconcat(i, args);
                NUNGCPRO;
        }

        if (NILP(ok_if_already_exists)
            || INTP(ok_if_already_exists))
                barf_or_query_if_file_exists(newname, "copy to it",
                                             INTP(ok_if_already_exists),
                                             &out_st);
        else if (sxemacs_stat((const char *)XSTRING_DATA(newname), &out_st) < 0)
                out_st.st_mode = 0;

        ifd = interruptible_open((char *)XSTRING_DATA(filename),
                                 O_RDONLY | OPEN_BINARY, 0);
        if (ifd < 0) {
                report_file_error("Opening input file", list1(filename));
                return;
        }
        record_unwind_protect(close_file_unwind, make_int(ifd));

        /* We can only copy regular files and symbolic links.  Other files are not
           copyable by us. */
        input_file_statable_p = (fstat(ifd, &st) >= 0);

        if (out_st.st_mode != 0
            && st.st_dev == out_st.st_dev && st.st_ino == out_st.st_ino) {
                errno = 0;
                report_file_error("Input and output files are the same",
                                  list2(filename, newname));
        }

#if defined (S_ISREG) && defined (S_ISLNK)
        if (input_file_statable_p) {
                if (!(S_ISREG(st.st_mode))
                    /* XEmacs: have to allow S_ISCHR in order to copy /dev/null */
#ifdef S_ISCHR
                    && !(S_ISCHR(st.st_mode))
#endif
                    && !(S_ISLNK(st.st_mode))) {
#if defined (EISDIR)
                        /* Get a better looking error message. */
                        errno = EISDIR;
#endif                          /* EISDIR */
                        report_file_error("Non-regular file", list1(filename));
                }
        }
#endif                          /* S_ISREG && S_ISLNK */

        ofd = open((char *)XSTRING_DATA(newname),
                   O_WRONLY | O_CREAT | O_TRUNC | OPEN_BINARY, CREAT_MODE);
        if (ofd < 0)
                report_file_error("Opening output file", list1(newname));

        {
                Lisp_Object ofd_locative = noseeum_cons(make_int(ofd), Qnil);

                record_unwind_protect(close_file_unwind, ofd_locative);

                while ((n = read_allowing_quit(ifd, buf, sizeof(buf))) > 0) {
                        if (write_allowing_quit(ofd, buf, n) != n)
                                report_file_error("I/O error", list1(newname));
                }

                if(close(ifd) <0)
                        report_file_error("I/O error", list1(filename));
                /* Closing the output clobbers the file times on some systems.  */
                if (close(ofd) < 0)
                        report_file_error("I/O error", list1(newname));

                if (input_file_statable_p) {
                        if (!NILP(keep_time)) {
                                EMACS_TIME atime, mtime;
                                EMACS_SET_SECS_USECS(atime, st.st_atime, 0);
                                EMACS_SET_SECS_USECS(mtime, st.st_mtime, 0);
                                if (set_file_times(newname, atime, mtime))
                                        report_file_error("I/O error",
                                                          list1(newname));
                        }
                        chmod((const char *)XSTRING_DATA(newname),
                              st.st_mode & 07777);
                }

                /* We'll close it by hand */
                XCAR(ofd_locative) = Qnil;

                /* Close ifd */
                unbind_to(speccount, Qnil);
        }

        UNGCPRO;
        return Qnil;
}
\f
DEFUN("make-directory-internal", Fmake_directory_internal, 1, 1, 0,     /*
Create a directory.  One argument, a file name string.
*/
      (dirname_))
{
        /* This function can GC.  GC checked 1997.04.06. */
        char dir[MAXPATHLEN];
        Lisp_Object handler;
        struct gcpro gcpro1;

        CHECK_STRING(dirname_);
        dirname_ = Fexpand_file_name(dirname_, Qnil);

        GCPRO1(dirname_);
        handler = Ffind_file_name_handler(dirname_, Qmake_directory_internal);
        UNGCPRO;
        if (!NILP(handler))
                return (call2(handler, Qmake_directory_internal, dirname_));

        if (XSTRING_LENGTH(dirname_) > (Bytecount) (sizeof(dir) - 1)) {
                return Fsignal(Qfile_error,
                               list3(build_translated_string
                                     ("Creating directory"),
                                     build_translated_string
                                     ("pathname too long"), dirname_));
        }
        strncpy(dir, (char *)XSTRING_DATA(dirname_),
                XSTRING_LENGTH(dirname_) + 1);
        dir[XSTRING_LENGTH(dirname_)]='\0';
        if (dir[XSTRING_LENGTH(dirname_) - 1] == '/')
                dir[XSTRING_LENGTH(dirname_) - 1] = '\0';

        if (mkdir(dir, 0777) != 0)
                report_file_error("Creating directory", list1(dirname_));

        return Qnil;
}

DEFUN("delete-directory", Fdelete_directory, 1, 1, "FDelete directory: ",       /*
Delete a directory.  One argument, a file name or directory name string.
*/
      (dirname_))
{
        /* This function can GC.  GC checked 1997.04.06. */
        Lisp_Object handler;
        struct gcpro gcpro1;

        CHECK_STRING(dirname_);

        GCPRO1(dirname_);
        dirname_ = Fexpand_file_name(dirname_, Qnil);
        dirname_ = Fdirectory_file_name(dirname_);

        handler = Ffind_file_name_handler(dirname_, Qdelete_directory);
        UNGCPRO;
        if (!NILP(handler))
                return (call2(handler, Qdelete_directory, dirname_));

        if (rmdir((char *)XSTRING_DATA(dirname_)) != 0)
                report_file_error("Removing directory", list1(dirname_));

        return Qnil;
}

DEFUN("delete-file", Fdelete_file, 1, 1, "fDelete file: ",      /*
Delete the file named FILENAME (a string).
If FILENAME has multiple names, it continues to exist with the other names.
*/
      (filename))
{
        /* This function can GC.  GC checked 1997.04.06. */
        Lisp_Object handler;
        struct gcpro gcpro1;

        CHECK_STRING(filename);
        filename = Fexpand_file_name(filename, Qnil);

        GCPRO1(filename);
        handler = Ffind_file_name_handler(filename, Qdelete_file);
        UNGCPRO;
        if (!NILP(handler))
                return call2(handler, Qdelete_file, filename);

        if (0 > unlink((char *)XSTRING_DATA(filename)))
                report_file_error("Removing old name", list1(filename));
        return Qnil;
}

static Lisp_Object
internal_delete_file_1(Lisp_Object ignore, Lisp_Object ignore2)
{
        return Qt;
}

/* Delete file FILENAME, returning 1 if successful and 0 if failed.  */

int internal_delete_file(Lisp_Object filename)
{
        /* This function can GC.  GC checked 1997.04.06. */
        return NILP(condition_case_1(Qt, Fdelete_file, filename,
                                     internal_delete_file_1, Qnil));
}
\f
DEFUN("rename-file", Frename_file, 2, 3, "fRename file: \nFRename %s to file: \np",     /*
Rename FILENAME as NEWNAME.  Both args must be strings.
If file has names other than FILENAME, it continues to have those names.
Signals a `file-already-exists' error if a file NEWNAME already exists
unless optional third argument OK-IF-ALREADY-EXISTS is non-nil.
A number as third arg means request confirmation if NEWNAME already exists.
This is what happens in interactive use with M-x.
*/
      (filename, newname, ok_if_already_exists))
{
        /* This function can GC.  GC checked 1997.04.06. */
        Lisp_Object handler;
        struct gcpro gcpro1, gcpro2;

        GCPRO2(filename, newname);
        CHECK_STRING(filename);
        CHECK_STRING(newname);
        filename = Fexpand_file_name(filename, Qnil);
        newname = Fexpand_file_name(newname, Qnil);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(filename, Qrename_file);
        if (NILP(handler))
                handler = Ffind_file_name_handler(newname, Qrename_file);
        if (!NILP(handler)) {
                UNGCPRO;
                return call4(handler, Qrename_file,
                             filename, newname, ok_if_already_exists);
        }

        /* When second argument is a directory, rename the file into it.
           (rename-file "foo" "bar/") == (rename-file "foo" "bar/foo")
         */
        if (!NILP(Ffile_directory_p(newname))) {
                Lisp_Object args[3] = {newname, Qnil, Qnil};
                struct gcpro ngcpro1;
                int i = 1;

                NGCPROn(args, countof(args));
                if (XSTRING_BYTE(newname, XSTRING_LENGTH(newname) - 1) != '/') {
                        args[i++] = build_string("/");
                }
                args[i++] = Ffile_name_nondirectory(filename);
                newname = Fconcat(i, args);
                NUNGCPRO;
        }

        if (NILP(ok_if_already_exists)
            || INTP(ok_if_already_exists))
                barf_or_query_if_file_exists(newname, "rename to it",
                                             INTP(ok_if_already_exists), 0);

/* Syncing with FSF 19.34.6 note: FSF does not have conditional code for
   WIN32_NATIVE here; I've removed it.  --marcpa */

        /* We have configure check for rename() and emulate using
           link()/unlink() if necessary. */
        if (0 > rename((char *)XSTRING_DATA(filename),
                       (char *)XSTRING_DATA(newname))) {
                if (errno == EXDEV) {
                        Fcopy_file(filename, newname,
                                   /* We have already prompted if it was an integer,
                                      so don't have copy-file prompt again.  */
                                   (NILP(ok_if_already_exists) ? Qnil : Qt),
                                   Qt);
                        Fdelete_file(filename);
                } else {
                        report_file_error("Renaming", list2(filename, newname));
                }
        }
        UNGCPRO;
        return Qnil;
}

DEFUN("add-name-to-file", Fadd_name_to_file, 2, 3, "fAdd name to file: \nFName to add to %s: \np",      /*
Give FILENAME additional name NEWNAME.  Both args must be strings.
Signals a `file-already-exists' error if a file NEWNAME already exists
unless optional third argument OK-IF-ALREADY-EXISTS is non-nil.
A number as third arg means request confirmation if NEWNAME already exists.
This is what happens in interactive use with M-x.
*/
      (filename, newname, ok_if_already_exists))
{
        /* This function can GC.  GC checked 1997.04.06. */
        Lisp_Object handler;
        struct gcpro gcpro1, gcpro2;

        GCPRO2(filename, newname);
        CHECK_STRING(filename);
        CHECK_STRING(newname);
        filename = Fexpand_file_name(filename, Qnil);
        newname = Fexpand_file_name(newname, Qnil);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(filename, Qadd_name_to_file);
        if (!NILP(handler))
                RETURN_UNGCPRO(call4(handler, Qadd_name_to_file, filename,
                                     newname, ok_if_already_exists));

        /* If the new name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(newname, Qadd_name_to_file);
        if (!NILP(handler))
                RETURN_UNGCPRO(call4(handler, Qadd_name_to_file, filename,
                                     newname, ok_if_already_exists));

        if (NILP(ok_if_already_exists)
            || INTP(ok_if_already_exists))
                barf_or_query_if_file_exists(newname, "make it a new name",
                                             INTP(ok_if_already_exists), 0);
/* Syncing with FSF 19.34.6 note: FSF does not report a file error
   on NT here. --marcpa */
/* But FSF #defines link as sys_link which is supplied in nt.c. We can't do
   that because sysfile.h defines sys_link depending on ENCAPSULATE_LINK.
   Reverted to previous behavior pending a working fix. (jhar) */

        unlink((char *)XSTRING_DATA(newname));
        if (0 > link((char *)XSTRING_DATA(filename),
                     (char *)XSTRING_DATA(newname))) {
                report_file_error("Adding new name", list2(filename, newname));
        }

        UNGCPRO;
        return Qnil;
}

DEFUN("make-symbolic-link", Fmake_symbolic_link, 2, 3, "FMake symbolic link to file: \nFMake symbolic link to file %s: \np",    /*
Make a symbolic link to FILENAME, named LINKNAME.  Both args strings.
Signals a `file-already-exists' error if a file LINKNAME already exists
unless optional third argument OK-IF-ALREADY-EXISTS is non-nil.
A number as third arg means request confirmation if LINKNAME already exists.
This happens for interactive use with M-x.
*/
      (filename, linkname, ok_if_already_exists))
{
        /* This function can GC.  GC checked 1997.06.04. */
        /* XEmacs change: run handlers even if local machine doesn't have symlinks */
        Lisp_Object handler;
        struct gcpro gcpro1, gcpro2;

        GCPRO2(filename, linkname);
        CHECK_STRING(filename);
        CHECK_STRING(linkname);
        /* If the link target has a ~, we must expand it to get
           a truly valid file name.  Otherwise, do not expand;
           we want to permit links to relative file names.  */
        if (XSTRING_BYTE(filename, 0) == '~')
                filename = Fexpand_file_name(filename, Qnil);
        linkname = Fexpand_file_name(linkname, Qnil);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(filename, Qmake_symbolic_link);
        if (!NILP(handler))
                RETURN_UNGCPRO(call4
                               (handler, Qmake_symbolic_link, filename,
                                linkname, ok_if_already_exists));

        /* If the new link name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(linkname, Qmake_symbolic_link);
        if (!NILP(handler))
                RETURN_UNGCPRO(call4(handler, Qmake_symbolic_link, filename,
                                     linkname, ok_if_already_exists));

#ifdef S_IFLNK
        if (NILP(ok_if_already_exists)
            || INTP(ok_if_already_exists))
                barf_or_query_if_file_exists(linkname, "make it a link",
                                             INTP(ok_if_already_exists), 0);

        unlink((char *)XSTRING_DATA(linkname));
        if (0 > symlink((char *)XSTRING_DATA(filename),
                        (char *)XSTRING_DATA(linkname))) {
                report_file_error("Making symbolic link",
                                  list2(filename, linkname));
        }
#endif                          /* S_IFLNK */

        UNGCPRO;
        return Qnil;
}

#ifdef HPUX_NET

DEFUN("sysnetunam", Fsysnetunam, 2, 2, 0,       /*
Open a network connection to PATH using LOGIN as the login string.
*/
      (path, login))
{
        int netresult;
        const char *path_ext;
        const char *login_ext;

        CHECK_STRING(path);
        CHECK_STRING(login);

        /* netunam, being a strange-o system call only used once, is not
           encapsulated. */

        LISP_STRING_TO_EXTERNAL(path, path_ext, Qfile_name);
        LISP_STRING_TO_EXTERNAL(login, login_ext, Qnative);

        netresult = netunam(path_ext, login_ext);

        return netresult == -1 ? Qnil : Qt;
}
#endif                          /* HPUX_NET */
\f
DEFUN("file-name-absolute-p", Ffile_name_absolute_p, 1, 1, 0,   /*
Return t if file FILENAME specifies an absolute path name.
On Unix, this is a name starting with a `/' or a `~'.
*/
      (filename))
{
        /* This function does not GC */
        Bufbyte *ptr;

        CHECK_STRING(filename);
        ptr = XSTRING_DATA(filename);
        return (IS_DIRECTORY_SEP(*ptr) || *ptr == '~'
            )? Qt : Qnil;
}
\f
/* Return nonzero if file FILENAME exists and can be executed.  */

static int check_executable(char *filename)
{
#ifdef HAVE_EACCESS
        return eaccess(filename, X_OK) >= 0;
#else
        /* Access isn't quite right because it uses the real uid
           and we really want to test with the effective uid.
           But Unix doesn't give us a right way to do it.  */
        return access(filename, X_OK) >= 0;
#endif                          /* HAVE_EACCESS */
}

/* Return nonzero if file FILENAME exists and can be written.  */

static int check_writable(const char *filename)
{
#ifdef HAVE_EACCESS
        return (eaccess(filename, W_OK) >= 0);
#else
        /* Access isn't quite right because it uses the real uid
           and we really want to test with the effective uid.
           But Unix doesn't give us a right way to do it.
           Opening with O_WRONLY could work for an ordinary file,
           but would lose for directories.  */
        return (access(filename, W_OK) >= 0);
#endif
}

DEFUN("file-exists-p", Ffile_exists_p, 1, 1, 0, /*
Return t if file FILENAME exists.  (This does not mean you can read it.)
See also `file-readable-p' and `file-attributes'.
*/
      (filename))
{
        /* This function can call lisp; GC checked 2000-07-11 ben */
        Lisp_Object abspath;
        Lisp_Object handler;
        struct stat statbuf;
        struct gcpro gcpro1;

        CHECK_STRING(filename);
        abspath = Fexpand_file_name(filename, Qnil);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        GCPRO1(abspath);
        handler = Ffind_file_name_handler(abspath, Qfile_exists_p);
        UNGCPRO;
        if (!NILP(handler))
                return call2(handler, Qfile_exists_p, abspath);

        return sxemacs_stat((char *)XSTRING_DATA(abspath),
                           &statbuf) >= 0 ? Qt : Qnil;
}

DEFUN("file-executable-p", Ffile_executable_p, 1, 1, 0, /*
Return t if FILENAME can be executed by you.
For a directory, this means you can access files in that directory.
*/
      (filename))
{
        /* This function can GC.  GC checked 07-11-2000 ben. */
        Lisp_Object abspath;
        Lisp_Object handler;
        struct gcpro gcpro1;

        CHECK_STRING(filename);
        abspath = Fexpand_file_name(filename, Qnil);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        GCPRO1(abspath);
        handler = Ffind_file_name_handler(abspath, Qfile_executable_p);
        UNGCPRO;
        if (!NILP(handler))
                return call2(handler, Qfile_executable_p, abspath);

        return check_executable((char *)XSTRING_DATA(abspath)) ? Qt : Qnil;
}

DEFUN("file-readable-p", Ffile_readable_p, 1, 1, 0,     /*
Return t if file FILENAME exists and you can read it.
See also `file-exists-p' and `file-attributes'.
*/
      (filename))
{
        /* This function can GC */
        Lisp_Object abspath = Qnil;
        Lisp_Object handler;
        struct gcpro gcpro1;
        GCPRO1(abspath);

        CHECK_STRING(filename);
        abspath = Fexpand_file_name(filename, Qnil);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(abspath, Qfile_readable_p);
        if (!NILP(handler))
                RETURN_UNGCPRO(call2(handler, Qfile_readable_p, abspath));

        {
                int desc =
                    interruptible_open((char *)XSTRING_DATA(abspath),
                                       O_RDONLY | OPEN_BINARY, 0);
                UNGCPRO;
                if (desc < 0)
                        return Qnil;
                close(desc);
                return Qt;
        }
}

/* Having this before file-symlink-p mysteriously caused it to be forgotten
   on the RT/PC.  */
DEFUN("file-writable-p", Ffile_writable_p, 1, 1, 0,     /*
Return t if file FILENAME can be written or created by you.
*/
      (filename))
{
        /* This function can GC.  GC checked 1997.04.10. */
        Lisp_Object abspath, dir;
        Lisp_Object handler;
        struct stat statbuf;
        struct gcpro gcpro1;

        CHECK_STRING(filename);
        abspath = Fexpand_file_name(filename, Qnil);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        GCPRO1(abspath);
        handler = Ffind_file_name_handler(abspath, Qfile_writable_p);
        UNGCPRO;
        if (!NILP(handler))
                return call2(handler, Qfile_writable_p, abspath);

        if (sxemacs_stat((char *)XSTRING_DATA(abspath), &statbuf) >= 0)
                return (check_writable((char *)XSTRING_DATA(abspath))
                        ? Qt : Qnil);

        GCPRO1(abspath);
        dir = Ffile_name_directory(abspath);
        UNGCPRO;
        return (check_writable(!NILP(dir) ? (char *)XSTRING_DATA(dir)
                               : "")
                ? Qt : Qnil);
}

DEFUN("file-symlink-p", Ffile_symlink_p, 1, 1, 0,       /*
Return non-nil if file FILENAME is the name of a symbolic link.
The value is the name of the file to which it is linked.
Otherwise returns nil.
*/
      (filename))
{
        /* This function can GC.  GC checked 1997.04.10. */
        /* XEmacs change: run handlers even if local machine doesn't have symlinks */
#ifdef S_IFLNK
        char *buf;
        int bufsize;
        int valsize;
        Lisp_Object val;
#endif
        Lisp_Object handler;
        struct gcpro gcpro1;

        CHECK_STRING(filename);
        filename = Fexpand_file_name(filename, Qnil);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        GCPRO1(filename);
        handler = Ffind_file_name_handler(filename, Qfile_symlink_p);
        UNGCPRO;
        if (!NILP(handler)) {
                return call2(handler, Qfile_symlink_p, filename);
        }
#ifdef S_IFLNK
        bufsize = 100;
        while (1) {
                buf = ynew_array_and_zero(char, bufsize);
                valsize = readlink((char *)XSTRING_DATA(filename),
                                   buf, bufsize);
                if (valsize < bufsize) {
                        break;
                }
                /* Buffer was not long enough */
                yfree(buf);
                bufsize *= 2;
        }
        if (valsize == -1) {
                yfree(buf);
                return Qnil;
        }
        val = make_string((Bufbyte*)buf, valsize);
        yfree(buf);
        return val;
#else                           /* not S_IFLNK */
        return Qnil;
#endif                          /* not S_IFLNK */
}

DEFUN("file-directory-p", Ffile_directory_p, 1, 1, 0,   /*
Return t if file FILENAME is the name of a directory as a file.
A directory name spec may be given instead; then the value is t
if the directory so specified exists and really is a directory.
*/
      (filename))
{
        /* This function can GC.  GC checked 1997.04.10. */
        Lisp_Object abspath;
        struct stat st;
        Lisp_Object handler;
        struct gcpro gcpro1;

        GCPRO1(current_buffer->directory);
        abspath = expand_and_dir_to_file(filename, current_buffer->directory);
        UNGCPRO;

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        GCPRO1(abspath);
        handler = Ffind_file_name_handler(abspath, Qfile_directory_p);
        UNGCPRO;
        if (!NILP(handler))
                return call2(handler, Qfile_directory_p, abspath);

        if (sxemacs_stat((char *)XSTRING_DATA(abspath), &st) < 0)
                return Qnil;
        return (st.st_mode & S_IFMT) == S_IFDIR ? Qt : Qnil;
}

DEFUN("file-accessible-directory-p", Ffile_accessible_directory_p, 1, 1, 0,     /*
Return t if file FILENAME is the name of a directory as a file,
and files in that directory can be opened by you.  In order to use a
directory as a buffer's current directory, this predicate must return true.
A directory name spec may be given instead; then the value is t
if the directory so specified exists and really is a readable and
searchable directory.
*/
      (filename))
{
        /* This function can GC.  GC checked 1997.04.10. */
        Lisp_Object handler;

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler =
            Ffind_file_name_handler(filename, Qfile_accessible_directory_p);
        if (!NILP(handler))
                return call2(handler, Qfile_accessible_directory_p, filename);

        if (NILP(Ffile_directory_p(filename)))
                return (Qnil);
        else
                return Ffile_executable_p(filename);
}

DEFUN("file-regular-p", Ffile_regular_p, 1, 1, 0,       /*
Return t if file FILENAME is the name of a regular file.
This is the sort of file that holds an ordinary stream of data bytes.
*/
      (filename))
{
        /* This function can GC.  GC checked 1997.04.10. */
        Lisp_Object abspath;
        struct stat st;
        Lisp_Object handler;
        struct gcpro gcpro1;

        GCPRO1(current_buffer->directory);
        abspath = expand_and_dir_to_file(filename, current_buffer->directory);
        UNGCPRO;

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        GCPRO1(abspath);
        handler = Ffind_file_name_handler(abspath, Qfile_regular_p);
        UNGCPRO;
        if (!NILP(handler))
                return call2(handler, Qfile_regular_p, abspath);

        if (sxemacs_stat((char *)XSTRING_DATA(abspath), &st) < 0)
                return Qnil;
        return (st.st_mode & S_IFMT) == S_IFREG ? Qt : Qnil;
}
\f
DEFUN("file-modes", Ffile_modes, 1, 1, 0,       /*
Return mode bits of file named FILENAME, as an integer.
*/
      (filename))
{
        /* This function can GC.  GC checked 1997.04.10. */
        Lisp_Object abspath;
        struct stat st;
        Lisp_Object handler;
        struct gcpro gcpro1;

        GCPRO1(current_buffer->directory);
        abspath = expand_and_dir_to_file(filename, current_buffer->directory);
        UNGCPRO;

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        GCPRO1(abspath);
        handler = Ffind_file_name_handler(abspath, Qfile_modes);
        UNGCPRO;
        if (!NILP(handler))
                return call2(handler, Qfile_modes, abspath);

        if (sxemacs_stat((char *)XSTRING_DATA(abspath), &st) < 0)
                return Qnil;
        /* Syncing with FSF 19.34.6 note: not in FSF, #if 0'ed out here. */

        return make_int(st.st_mode & 07777);
}

DEFUN("set-file-modes", Fset_file_modes, 2, 2, 0,       /*
Set mode bits of file named FILENAME to MODE (an integer).
Only the 12 low bits of MODE are used.
*/
      (filename, mode))
{
        /* This function can GC.  GC checked 1997.04.10. */
        Lisp_Object abspath;
        Lisp_Object handler;
        struct gcpro gcpro1;

        GCPRO1(current_buffer->directory);
        abspath = Fexpand_file_name(filename, current_buffer->directory);
        UNGCPRO;

        CHECK_INT(mode);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        GCPRO1(abspath);
        handler = Ffind_file_name_handler(abspath, Qset_file_modes);
        UNGCPRO;
        if (!NILP(handler))
                return call3(handler, Qset_file_modes, abspath, mode);

        if (chmod((char *)XSTRING_DATA(abspath), XINT(mode)) < 0)
                report_file_error("Doing chmod", list1(abspath));

        return Qnil;
}

DEFUN("set-default-file-modes", Fset_default_file_modes, 1, 1, 0,       /*
Set the file permission bits for newly created files.
The argument MODE should be an integer; if a bit in MODE is 1,
subsequently created files will not have the permission corresponding
to that bit enabled.  Only the low 9 bits are used.
This setting is inherited by subprocesses.
*/
      (mode))
{
        CHECK_INT(mode);

        umask((~XINT(mode)) & 0777);

        return Qnil;
}

DEFUN("default-file-modes", Fdefault_file_modes, 0, 0, 0,       /*
Return the default file protection for created files.
The umask value determines which permissions are enabled in newly
created files.  If a permission's bit in the umask is 1, subsequently
created files will not have that permission enabled.
*/
      ())
{
        int mode;

        mode = umask(0);
        umask(mode);

        return make_int((~mode) & 0777);
}
\f
DEFUN("unix-sync", Funix_sync, 0, 0, "",        /*
Tell Unix to finish all pending disk updates.
*/
      ())
{
        sync();
        return Qnil;
}
\f
DEFUN("file-newer-than-file-p", Ffile_newer_than_file_p, 2, 2, 0,       /*
Return t if file FILE1 is newer than file FILE2.
If FILE1 does not exist, the answer is nil;
otherwise, if FILE2 does not exist, the answer is t.
*/
      (file1, file2))
{
        /* This function can GC.  GC checked 1997.04.10. */
        Lisp_Object abspath1, abspath2;
        struct stat st;
        int mtime1;
        Lisp_Object handler;
        struct gcpro gcpro1, gcpro2, gcpro3;

        CHECK_STRING(file1);
        CHECK_STRING(file2);

        abspath1 = Qnil;
        abspath2 = Qnil;

        GCPRO3(abspath1, abspath2, current_buffer->directory);
        abspath1 = expand_and_dir_to_file(file1, current_buffer->directory);
        abspath2 = expand_and_dir_to_file(file2, current_buffer->directory);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(abspath1, Qfile_newer_than_file_p);
        if (NILP(handler))
                handler =
                    Ffind_file_name_handler(abspath2, Qfile_newer_than_file_p);
        UNGCPRO;
        if (!NILP(handler))
                return call3(handler, Qfile_newer_than_file_p, abspath1,
                             abspath2);

        if (sxemacs_stat((char *)XSTRING_DATA(abspath1), &st) < 0)
                return Qnil;

        mtime1 = st.st_mtime;

        if (sxemacs_stat((char *)XSTRING_DATA(abspath2), &st) < 0)
                return Qt;

        return (mtime1 > st.st_mtime) ? Qt : Qnil;
}
\f
/* Stack sizes > 2**16 is a good way to elicit compiler bugs */
/* #define READ_BUF_SIZE (2 << 16) */
#define READ_BUF_SIZE (1 << 15)

DEFUN("insert-file-contents-internal", Finsert_file_contents_internal, 1, 7, 0, /*
Insert contents of file FILENAME after point; no coding-system frobbing.
This function is identical to `insert-file-contents' except for the
handling of the CODESYS and USED-CODESYS arguments under
SXEmacs/Mule. (When Mule support is not present, both functions are
identical and ignore the CODESYS and USED-CODESYS arguments.)

If support for Mule exists in this Emacs, the file is decoded according
to CODESYS; if omitted, no conversion happens.  If USED-CODESYS is non-nil,
it should be a symbol, and the actual coding system that was used for the
decoding is stored into it.  It will in general be different from CODESYS
if CODESYS specifies automatic encoding detection or end-of-line detection.

Currently START and END refer to byte positions (as opposed to character
positions), even in Mule. (Fixing this is very difficult.)
*/
      (filename, visit, start, end, replace, codesys, used_codesys))
{
        /* This function can call lisp */
        struct stat st;
        int fd;
        int saverrno = 0;
        Charcount inserted = 0;
        int speccount;
        struct gcpro gcpro1, gcpro2, gcpro3, gcpro4, gcpro5;
        Lisp_Object handler = Qnil, val = Qnil;
        int total;
        Bufbyte read_buf[READ_BUF_SIZE];
        int mc_count;
        struct buffer *buf = current_buffer;
        Lisp_Object curbuf;
        int not_regular = 0;

        if (UNLIKELY(buf->base_buffer && !NILP(visit))) {
                error("Cannot do file visiting in an indirect buffer");
        }

        /* No need to call Fbarf_if_buffer_read_only() here.
           That's called in begin_multiple_change() or wherever. */
        /* #### dmoore - should probably check in various places to see if
           curbuf was killed and if so signal an error? */
        XSETBUFFER(curbuf, buf);

        GCPRO5(filename, val, visit, handler, curbuf);

        if (LIKELY(NILP(replace))) {
                mc_count = begin_multiple_change(buf, BUF_PT(buf), BUF_PT(buf));
        } else {
                mc_count = begin_multiple_change(buf, BUF_BEG(buf), BUF_Z(buf));
        }

        /* begin_multiple_change also adds an unwind_protect */
        speccount = specpdl_depth();

        filename = Fexpand_file_name(filename, Qnil);

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(filename, Qinsert_file_contents);
        if (!NILP(handler)) {
                val = call6(handler, Qinsert_file_contents, filename,
                            visit, start, end, replace);
                goto handled;
        }
#ifdef FILE_CODING
        if (!NILP(used_codesys))
                CHECK_SYMBOL(used_codesys);
#endif

        if ((!NILP(start) || !NILP(end)) && !NILP(visit))
                error("Attempt to visit less than an entire file");

        fd = -1;

        if (sxemacs_stat((char *)XSTRING_DATA(filename), &st) < 0) {
                if (fd >= 0)
                        close(fd);
              badopen:
                if (NILP(visit))
                        report_file_error("Opening input file",
                                          list1(filename));
                st.st_mtime = -1;
                goto notfound;
        }
#ifdef S_IFREG
        /* Signal an error if we are accessing a non-regular file, with
           REPLACE, START or END being non-nil.  */
        if (!S_ISREG(st.st_mode)) {
                not_regular = 1;

                if (!NILP(visit))
                        goto notfound;

                if (!NILP(replace) || !NILP(start) || !NILP(end)) {
                        end_multiple_change(buf, mc_count);

                        RETURN_UNGCPRO
                            (Fsignal(Qfile_error,
                                     list2(build_translated_string
                                           ("not a regular file"), filename)));
                }
        }
#endif                          /* S_IFREG */

        if (!NILP(start))
                CHECK_INT(start);
        else
                start = Qzero;

        if (!NILP(end))
                CHECK_INT(end);

        if (fd < 0) {
                if ((fd = interruptible_open((char *)XSTRING_DATA(filename),
                                             O_RDONLY | OPEN_BINARY, 0)) < 0)
                        goto badopen;
        }

        /* Replacement should preserve point as it preserves markers.  */
        if (!NILP(replace))
                record_unwind_protect(restore_point_unwind,
                                      Fpoint_marker(Qnil, Qnil));

        record_unwind_protect(close_file_unwind, make_int(fd));

        /* Supposedly happens on VMS.  */
        if (st.st_size < 0)
                error("File size is negative");

        if (NILP(end)) {
                if (!not_regular) {
                        end = make_int(st.st_size);
                        if (XINT(end) != st.st_size)
                                error("Maximum buffer size exceeded");
                }
        }

        /* If requested, replace the accessible part of the buffer
           with the file contents.  Avoid replacing text at the
           beginning or end of the buffer that matches the file contents;
           that preserves markers pointing to the unchanged parts.  */
#if !defined (FILE_CODING)
        /* The replace-mode code currently only works when the assumption
           'one byte == one char' holds true.  This fails Mule because
           files may contain multibyte characters.  It holds under Windows NT
           provided we convert CRLF into LF. */
# define FSFMACS_SPEEDY_INSERT
#endif                          /* !defined (FILE_CODING) */

#ifndef FSFMACS_SPEEDY_INSERT
        if (!NILP(replace)) {
                buffer_delete_range(buf, BUF_BEG(buf), BUF_Z(buf),
                                    !NILP(visit) ? INSDEL_NO_LOCKING : 0);
        }
#else                           /* FSFMACS_SPEEDY_INSERT */
        if (!NILP(replace)) {
                char buffer[1 << 14];
                Bufpos same_at_start = BUF_BEGV(buf);
                Bufpos same_at_end = BUF_ZV(buf);
                int overlap;

                /* Count how many chars at the start of the file
                   match the text at the beginning of the buffer.  */
                while (1) {
                        int nread;
                        Bufpos bufpos;
                        nread = read_allowing_quit(fd, buffer, sizeof buffer);
                        if (nread < 0)
                                error("IO error reading %s: %s",
                                      XSTRING_DATA(filename), strerror(errno));
                        else if (nread == 0)
                                break;
                        bufpos = 0;
                        while (bufpos < nread && same_at_start < BUF_ZV(buf)
                               && BUF_FETCH_CHAR(buf,
                                                 same_at_start) ==
                               buffer[bufpos])
                                same_at_start++, bufpos++;
                        /* If we found a discrepancy, stop the scan.
                           Otherwise loop around and scan the next bufferful.  */
                        if (bufpos != nread)
                                break;
                }
                /* If the file matches the buffer completely,
                   there's no need to replace anything.  */
                if (same_at_start - BUF_BEGV(buf) == st.st_size) {
                        close(fd);
                        unbind_to(speccount, Qnil);
                        /* Truncate the buffer to the size of the file.  */
                        buffer_delete_range(buf, same_at_start, same_at_end,
                                            !NILP(visit) ? INSDEL_NO_LOCKING :
                                            0);
                        goto handled;
                }
                /* Count how many chars at the end of the file
                   match the text at the end of the buffer.  */
                while (1) {
                        int total_read, nread;
                        Bufpos bufpos, curpos, trial;

                        /* At what file position are we now scanning?  */
                        curpos = st.st_size - (BUF_ZV(buf) - same_at_end);
                        /* If the entire file matches the buffer tail, stop the scan.  */
                        if (curpos == 0)
                                break;
                        /* How much can we scan in the next step?  */
                        trial = min(curpos, (Bufpos) sizeof(buffer));
                        if (lseek(fd, curpos - trial, 0) < 0)
                                report_file_error("Setting file position",
                                                  list1(filename));

                        total_read = 0;
                        while (total_read < trial) {
                                nread =
                                    read_allowing_quit(fd, buffer + total_read,
                                                       trial - total_read);
                                if (nread <= 0)
                                        report_file_error
                                            ("IO error reading file",
                                             list1(filename));
                                total_read += nread;
                        }
                        /* Scan this bufferful from the end, comparing with
                           the Emacs buffer.  */
                        bufpos = total_read;
                        /* Compare with same_at_start to avoid counting some buffer text
                           as matching both at the file's beginning and at the end.  */
                        while (bufpos > 0 && same_at_end > same_at_start
                               && BUF_FETCH_CHAR(buf, same_at_end - 1) ==
                               buffer[bufpos - 1])
                                same_at_end--, bufpos--;
                        /* If we found a discrepancy, stop the scan.
                           Otherwise loop around and scan the preceding bufferful.  */
                        if (bufpos != 0)
                                break;
                        /* If display current starts at beginning of line,
                           keep it that way.  */
                        if (XBUFFER(XWINDOW(Fselected_window(Qnil))->buffer) ==
                            buf)
                                XWINDOW(Fselected_window(Qnil))->
                                    start_at_line_beg =
                                    !NILP(Fbolp(make_buffer(buf)));
                }

                /* Don't try to reuse the same piece of text twice.  */
                overlap = same_at_start - BUF_BEGV(buf) -
                    (same_at_end + st.st_size - BUF_ZV(buf));
                if (overlap > 0)
                        same_at_end += overlap;

                /* Arrange to read only the nonmatching middle part of the file.  */
                start = make_int(same_at_start - BUF_BEGV(buf));
                end = make_int(st.st_size - (BUF_ZV(buf) - same_at_end));

                buffer_delete_range(buf, same_at_start, same_at_end,
                                    !NILP(visit) ? INSDEL_NO_LOCKING : 0);
                /* Insert from the file at the proper position.  */
                BUF_SET_PT(buf, same_at_start);
        }
#endif                          /* FSFMACS_SPEEDY_INSERT */

        if (!not_regular) {
                total = XINT(end) - XINT(start);

                /* Make sure point-max won't overflow after this insertion.  */
                if (total != XINT(make_int(total)))
                        error("Maximum buffer size exceeded");
        } else
                /* For a special file, all we can do is guess.  The value of -1
                   will make the stream functions read as much as possible.  */
                total = -1;

        if (XINT(start) != 0
#ifdef FSFMACS_SPEEDY_INSERT
            /* why was this here? asked jwz.  The reason is that the replace-mode
               connivings above will normally put the file pointer other than
               where it should be. */
            || !NILP(replace)
#endif                          /* !FSFMACS_SPEEDY_INSERT */
            ) {
                if (lseek(fd, XINT(start), 0) < 0)
                        report_file_error("Setting file position",
                                          list1(filename));
        }

        {
                Bufpos cur_point = BUF_PT(buf);
                struct gcpro ngcpro1;
                Lisp_Object stream = make_filedesc_input_stream(fd, 0, total,
                                                                LSTR_ALLOW_QUIT);

                NGCPRO1(stream);
                Lstream_set_buffering(XLSTREAM(stream), LSTREAM_BLOCKN_BUFFERED,
                                      65536);
#ifdef FILE_CODING
                stream = make_decoding_input_stream
                    (XLSTREAM(stream), Fget_coding_system(codesys));
                Lstream_set_character_mode(XLSTREAM(stream));
                Lstream_set_buffering(XLSTREAM(stream), LSTREAM_BLOCKN_BUFFERED,
                                      65536);
#endif                          /* FILE_CODING */

                record_unwind_protect(delete_stream_unwind, stream);

                /* No need to limit the amount of stuff we attempt to read. (It would
                   be incorrect, anyway, when Mule is enabled.) Instead, the limiting
                   occurs inside of the filedesc stream. */
                while (1) {
                        Lstream_data_count this_len;
                        Charcount cc_inserted;

                        QUIT;
                        this_len = Lstream_read(XLSTREAM(stream), read_buf,
                                                sizeof(read_buf));

                        if (this_len <= 0) {
                                if (this_len < 0)
                                        saverrno = errno;
                                break;
                        }

                        cc_inserted =
                            buffer_insert_raw_string_1(buf, cur_point, read_buf,
                                                       this_len, !NILP(visit)
                                                       ? INSDEL_NO_LOCKING : 0);
                        inserted += cc_inserted;
                        cur_point += cc_inserted;
                }
#ifdef FILE_CODING
                if (!NILP(used_codesys)) {
                        Lisp_Object tmp =
                                decoding_stream_coding_system(XLSTREAM(stream));
                        Fset(used_codesys, XCODING_SYSTEM_NAME(tmp));
                }
#endif                          /* FILE_CODING */
                NUNGCPRO;
        }

        /* Close the file/stream */
        unbind_to(speccount, Qnil);

        if (saverrno != 0) {
                error("IO error reading %s: %s",
                      XSTRING_DATA(filename), strerror(saverrno));
        }

      notfound:
      handled:

        end_multiple_change(buf, mc_count);

        if (!NILP(visit)) {
                if (!EQ(buf->undo_list, Qt))
                        buf->undo_list = Qnil;
                if (NILP(handler)) {
                        buf->modtime = st.st_mtime;
                        buf->filename = filename;
                        /* XEmacs addition: */
                        /* This function used to be in C, ostensibly so that
                           it could be called here.  But that's just silly.
                           There's no reason C code can't call out to Lisp
                           code, and it's a lot cleaner this way. */
                        /*  Note: compute-buffer-file-truename is called for
                           side-effect!  Its return value is intentionally
                           ignored. */
                        if (!NILP(Ffboundp(Qcompute_buffer_file_truename)))
                                call1(Qcompute_buffer_file_truename,
                                      make_buffer(buf));
                }
                BUF_SAVE_MODIFF(buf) = BUF_MODIFF(buf);
                buf->auto_save_modified = BUF_MODIFF(buf);
                buf->saved_size = make_int(BUF_SIZE(buf));
#ifdef CLASH_DETECTION
                if (NILP(handler)) {
                        if (!NILP(buf->file_truename))
                                unlock_file(buf->file_truename);
                        unlock_file(filename);
                }
#endif                          /* CLASH_DETECTION */
                if (not_regular)
                        RETURN_UNGCPRO(Fsignal(Qfile_error,
                                               list2(build_string
                                                     ("not a regular file"),
                                                     filename)));

                /* If visiting nonexistent file, return nil.  */
                if (buf->modtime == -1)
                        report_file_error("Opening input file",
                                          list1(filename));
        }

        /* Decode file format */
        if (inserted > 0) {
                Lisp_Object insval = call3(Qformat_decode,
                                           Qnil, make_int(inserted), visit);
                CHECK_INT(insval);
                inserted = XINT(insval);
        }

        if (inserted > 0) {
                Lisp_Object p;
                struct gcpro ngcpro1;

                NGCPRO1(p);
                EXTERNAL_LIST_LOOP(p, Vafter_insert_file_functions) {
                        Lisp_Object insval = call1(XCAR(p), make_int(inserted));
                        if (!NILP(insval)) {
                                CHECK_NATNUM(insval);
                                inserted = XINT(insval);
                        }
                        QUIT;
                }
                NUNGCPRO;
        }

        UNGCPRO;

        if (!NILP(val))
                return (val);
        else
                return (list2(filename, make_int(inserted)));
}
\f
static int a_write(Lisp_Object outstream, Lisp_Object instream, int pos,
                   Lisp_Object * annot);
static Lisp_Object build_annotations(Lisp_Object start, Lisp_Object end);

/* If build_annotations switched buffers, switch back to BUF.
   Kill the temporary buffer that was selected in the meantime.  */

static Lisp_Object build_annotations_unwind(Lisp_Object buf)
{
        Lisp_Object tembuf;

        if (XBUFFER(buf) == current_buffer)
                return Qnil;
        tembuf = Fcurrent_buffer();
        Fset_buffer(buf);
        Fkill_buffer(tembuf);
        return Qnil;
}

DEFUN("write-region-internal", Fwrite_region_internal, 3, 7, "r\nFWrite region to file: ",      /*
Write current region into specified file; no coding-system frobbing.
This function is identical to `write-region' except for the handling
of the CODESYS argument under SXEmacs/Mule. (When Mule support is not
present, both functions are identical and ignore the CODESYS argument.)
If support for Mule exists in this Emacs, the file is encoded according
to the value of CODESYS.  If this is nil, no code conversion occurs.

As a special kludge to support auto-saving, when START is nil START and
END are set to the beginning and end, respectively, of the buffer,
regardless of any restrictions.  Don't use this feature.  It is documented
here because write-region handler writers need to be aware of it.
*/
      (start, end, filename, append, visit, lockname, codesys))
{
        /* This function can call lisp.  GC checked 2000-07-28 ben */
        int desc;
        int failure, stat_res;
        int save_errno = 0;
        struct stat st;
        Lisp_Object fn = Qnil;
        int speccount = specpdl_depth();
        int visiting_other = STRINGP(visit);
        int visiting = (EQ(visit, Qt) || visiting_other);
        int quietly = (!visiting && !NILP(visit));
        Lisp_Object visit_file = Qnil;
        Lisp_Object annotations = Qnil;
        struct buffer *given_buffer;
        Bufpos start1, end1;
        struct gcpro gcpro1, gcpro2, gcpro3, gcpro4, gcpro5;
        struct gcpro ngcpro1, ngcpro2;
        Lisp_Object curbuf;

        XSETBUFFER(curbuf, current_buffer);

        /* start, end, visit, and append are never modified in this fun
           so we don't protect them. */
        GCPRO5(visit_file, filename, codesys, lockname, annotations);
        NGCPRO2(curbuf, fn);

        /* [[ dmoore - if Fexpand_file_name or handlers kill the buffer,
           we should signal an error rather than blissfully continuing
           along.  ARGH, this function is going to lose lose lose.  We need
           to protect the current_buffer from being destroyed, but the
           multiple return points make this a pain in the butt. ]] we do
           protect curbuf now. --ben */

#ifdef FILE_CODING
        codesys = Fget_coding_system(codesys);
#endif                          /* FILE_CODING */

        if (current_buffer->base_buffer && !NILP(visit))
                invalid_operation
                    ("Cannot do file visiting in an indirect buffer", curbuf);

        if (!NILP(start) && !STRINGP(start))
                get_buffer_range_char(current_buffer, start, end, &start1,
                                      &end1, 0);

        {
                Lisp_Object handler;

                if (visiting_other)
                        visit_file = Fexpand_file_name(visit, Qnil);
                else
                        visit_file = filename;
                filename = Fexpand_file_name(filename, Qnil);

                if (NILP(lockname))
                        lockname = visit_file;

                /* We used to UNGCPRO here.  BAD!  visit_file is used below after
                   more Lisp calling. */
                /* If the file name has special constructs in it,
                   call the corresponding file handler.  */
                handler = Ffind_file_name_handler(filename, Qwrite_region);
                /* If FILENAME has no handler, see if VISIT has one.  */
                if (NILP(handler) && STRINGP(visit))
                        handler = Ffind_file_name_handler(visit, Qwrite_region);

                if (!NILP(handler)) {
                        Lisp_Object val =
                            call8(handler, Qwrite_region, start, end,
                                  filename, append, visit, lockname, codesys);
                        if (visiting) {
                                BUF_SAVE_MODIFF(current_buffer) =
                                    BUF_MODIFF(current_buffer);
                                current_buffer->saved_size =
                                    make_int(BUF_SIZE(current_buffer));
                                current_buffer->filename = visit_file;
                                MARK_MODELINE_CHANGED;
                        }
                        NUNGCPRO;
                        UNGCPRO;
                        return val;
                }
        }

#ifdef CLASH_DETECTION
        if (!auto_saving)
                lock_file(lockname);
#endif                          /* CLASH_DETECTION */

        /* Special kludge to simplify auto-saving.  */
        if (NILP(start)) {
                start1 = BUF_BEG(current_buffer);
                end1 = BUF_Z(current_buffer);
        }

        record_unwind_protect(build_annotations_unwind, Fcurrent_buffer());

        given_buffer = current_buffer;
        annotations = build_annotations(start, end);
        if (current_buffer != given_buffer) {
                start1 = BUF_BEGV(current_buffer);
                end1 = BUF_ZV(current_buffer);
        }

        fn = filename;
        desc = -1;
        if (!NILP(append)) {
                desc =
                    open((char *)XSTRING_DATA(fn), O_WRONLY | OPEN_BINARY, 0);
        }
        if (desc < 0) {
                desc = open((char *)XSTRING_DATA(fn),
                            O_WRONLY | O_TRUNC | O_CREAT | OPEN_BINARY,
                            auto_saving ? auto_save_mode_bits : CREAT_MODE);
        }

        if (desc < 0) {
#ifdef CLASH_DETECTION
                save_errno = errno;
                if (!auto_saving)
                        unlock_file(lockname);
                errno = save_errno;
#endif                          /* CLASH_DETECTION */
                report_file_error("Opening output file", list1(filename));
        }

        {
                Lisp_Object desc_locative = Fcons(make_int(desc), Qnil);
                Lisp_Object instream = Qnil, outstream = Qnil;
                struct gcpro nngcpro1, nngcpro2;
                /* need to gcpro; QUIT could happen out of call to write() */
                NNGCPRO2(instream, outstream);

                record_unwind_protect(close_file_unwind, desc_locative);

                if (!NILP(append)) {
                        if (lseek(desc, 0, 2) < 0) {
#ifdef CLASH_DETECTION
                                if (!auto_saving)
                                        unlock_file(lockname);
#endif                          /* CLASH_DETECTION */
                                report_file_error("Lseek error",
                                                  list1(filename));
                        }
                }

                failure = 0;

                /* Note: I tried increasing the buffering size, along with
                   various other tricks, but nothing seemed to make much of
                   a difference in the time it took to save a large file.
                   (Actually that's not true.  With a local disk, changing
                   the buffer size doesn't seem to make much difference.
                   With an NFS-mounted disk, it could make a lot of difference
                   because you're affecting the number of network requests
                   that need to be made, and there could be a large latency
                   for each request.  So I've increased the buffer size
                   to 64K.) */
                outstream = make_filedesc_output_stream(desc, 0, -1, 0);
                Lstream_set_buffering(XLSTREAM(outstream),
                                      LSTREAM_BLOCKN_BUFFERED, 65536);
#ifdef FILE_CODING
                outstream =
                    make_encoding_output_stream(XLSTREAM(outstream), codesys);
                Lstream_set_buffering(XLSTREAM(outstream),
                                      LSTREAM_BLOCKN_BUFFERED, 65536);
#endif                          /* FILE_CODING */
                if (STRINGP(start)) {
                        instream = make_lisp_string_input_stream(start, 0, -1);
                        start1 = 0;
                } else
                        instream =
                            make_lisp_buffer_input_stream(current_buffer,
                                                          start1, end1,
                                                          LSTR_SELECTIVE |
                                                          LSTR_IGNORE_ACCESSIBLE);
                failure =
                    (0 > (a_write(outstream, instream, start1, &annotations)));
                save_errno = errno;
                /* Note that this doesn't close the desc since we created the
                   stream without the LSTR_CLOSING flag, but it does
                   flush out any buffered data. */
                if (Lstream_close(XLSTREAM(outstream)) < 0) {
                        failure = 1;
                        save_errno = errno;
                }
                Lstream_close(XLSTREAM(instream));

#ifdef HAVE_FSYNC
                /* Note fsync appears to change the modtime on BSD4.2 (both vax and sun).
                   Disk full in NFS may be reported here.  */
                /* mib says that closing the file will try to write as fast as NFS can do
                   it, and that means the fsync here is not crucial for autosave files.  */
                if (!auto_saving && fsync(desc) < 0
                    /* If fsync fails with EINTR, don't treat that as serious.  */
                    && errno != EINTR) {
                        failure = 1;
                        save_errno = errno;
                }
#endif                          /* HAVE_FSYNC */

                /* Spurious "file has changed on disk" warnings used to be seen on
                   systems where close() can change the modtime.  This is known to
                   happen on various NFS file systems, on Windows, and on Linux.
                   Rather than handling this on a per-system basis, we
                   unconditionally do the sxemacs_stat() after the close(). */

                /* NFS can report a write failure now.  */
                if (close(desc) < 0) {
                        failure = 1;
                        save_errno = errno;
                }

                /* Discard the close unwind-protect.  Execute the one for
                   build_annotations (switches back to the original current buffer
                   as necessary). */
                XCAR(desc_locative) = Qnil;
                unbind_to(speccount, Qnil);

                NNUNGCPRO;
        }

        stat_res = sxemacs_stat((char *)XSTRING_DATA(fn), &st);

#ifdef CLASH_DETECTION
        if (!auto_saving)
                unlock_file(lockname);
#endif                          /* CLASH_DETECTION */

        /* Do this before reporting IO error
           to avoid a "file has changed on disk" warning on
           next attempt to save.  */
        if (visiting)
           if (stat_res == 0)
                current_buffer->modtime = st.st_mtime;
           /* else:
                If sxemacs_stat failed, we have bigger problems, and
                   most likely the file is gone, so the error next time is
                   the right behavior
            */

        if (failure) {
                errno = save_errno;
                report_file_error("Writing file", list1(fn));
        }

        if (visiting) {
                BUF_SAVE_MODIFF(current_buffer) = BUF_MODIFF(current_buffer);
                current_buffer->saved_size = make_int(BUF_SIZE(current_buffer));
                current_buffer->filename = visit_file;
                MARK_MODELINE_CHANGED;
        } else if (quietly) {
                NUNGCPRO;
                UNGCPRO;
                return Qnil;
        }

        if (!auto_saving) {
                if (visiting_other)
                        message("Wrote %s", XSTRING_DATA(visit_file));
                else {
                        Lisp_Object fsp = Qnil;
                        struct gcpro nngcpro1;

                        NNGCPRO1(fsp);
                        fsp = Ffile_symlink_p(fn);
                        if (NILP(fsp))
                                message("Wrote %s", XSTRING_DATA(fn));
                        else
                                message("Wrote %s (symlink to %s)",
                                        XSTRING_DATA(fn), XSTRING_DATA(fsp));
                        NNUNGCPRO;
                }
        }
        NUNGCPRO;
        UNGCPRO;
        return Qnil;
}

/* #### This is such a load of shit!!!!  There is no way we should define
   something so stupid as a subr, just sort the fucking list more
   intelligently. */
DEFUN("car-less-than-car", Fcar_less_than_car, 2, 2, 0, /*
Return t if (car A) is numerically less than (car B).
*/
      (a, b))
{
        if (ent_binrel(ASE_BINARY_REL_LESSP, Fcar(a), Fcar(b)))
                return Qt;
        else
                return Qnil;;
}

/* Heh heh heh, let's define this too, just to aggravate the person who
   wrote the above comment. */
DEFUN("cdr-less-than-cdr", Fcdr_less_than_cdr, 2, 2, 0, /*
Return t if (cdr A) is numerically less than (cdr B).
*/
      (a, b))
{
        if (ent_binrel(ASE_BINARY_REL_LESSP, Fcdr(a), Fcdr(b)))
                return Qt;
        else
                return Qnil;
}

/* Build the complete list of annotations appropriate for writing out
   the text between START and END, by calling all the functions in
   write-region-annotate-functions and merging the lists they return.
   If one of these functions switches to a different buffer, we assume
   that buffer contains altered text.  Therefore, the caller must
   make sure to restore the current buffer in all cases,
   as save-excursion would do.  */

static Lisp_Object build_annotations(Lisp_Object start, Lisp_Object end)
{
        /* This function can GC */
        Lisp_Object annotations;
        Lisp_Object p, res;
        struct gcpro gcpro1, gcpro2;
        Lisp_Object original_buffer;

        XSETBUFFER(original_buffer, current_buffer);

        annotations = Qnil;
        p = Vwrite_region_annotate_functions;
        GCPRO2(annotations, p);
        while (!NILP(p)) {
                struct buffer *given_buffer = current_buffer;
                Vwrite_region_annotations_so_far = annotations;
                res = call2(Fcar(p), start, end);
                /* If the function makes a different buffer current,
                   assume that means this buffer contains altered text to be output.
                   Reset START and END from the buffer bounds
                   and discard all previous annotations because they should have
                   been dealt with by this function.  */
                if (current_buffer != given_buffer) {
                        start = make_int(BUF_BEGV(current_buffer));
                        end = make_int(BUF_ZV(current_buffer));
                        annotations = Qnil;
                }
                Flength(res);   /* Check basic validity of return value */
                annotations = merge(annotations, res, Qcar_less_than_car);
                p = Fcdr(p);
        }

        /* Now do the same for annotation functions implied by the file-format */
        if (auto_saving && (!EQ(Vauto_save_file_format, Qt)))
                p = Vauto_save_file_format;
        else
                p = current_buffer->file_format;
        while (!NILP(p)) {
                struct buffer *given_buffer = current_buffer;
                Vwrite_region_annotations_so_far = annotations;
                res = call4(Qformat_annotate_function, Fcar(p), start, end,
                            original_buffer);
                if (current_buffer != given_buffer) {
                        start = make_int(BUF_BEGV(current_buffer));
                        end = make_int(BUF_ZV(current_buffer));
                        annotations = Qnil;
                }
                Flength(res);
                annotations = merge(annotations, res, Qcar_less_than_car);
                p = Fcdr(p);
        }
        UNGCPRO;
        return annotations;
}

/* Write to stream OUTSTREAM the characters from INSTREAM (it is read until
   EOF is encountered), assuming they start at position POS in the buffer
   of string that STREAM refers to.  Intersperse with them the annotations
   from *ANNOT that fall into the range of positions we are reading from,
   each at its appropriate position.

   Modify *ANNOT by discarding elements as we output them.
   The return value is negative in case of system call failure.  */

/* 4K should probably be fine.  We just need to reduce the number of
   function calls to reasonable level.  The Lstream stuff itself will
   batch to 64K to reduce the number of system calls. */

#define A_WRITE_BATCH_SIZE 4096

static int
a_write(Lisp_Object outstream, Lisp_Object instream, int pos,
        Lisp_Object * annot)
{
        Lisp_Object tem;
        int nextpos;
        unsigned char largebuf[A_WRITE_BATCH_SIZE];
        Lstream *instr = XLSTREAM(instream);
        Lstream *outstr = XLSTREAM(outstream);

        while (LISTP(*annot)) {
                tem = Fcar_safe(Fcar(*annot));
                if (INTP(tem))
                        nextpos = XINT(tem);
                else
                        nextpos = INT_MAX;
#ifdef MULE
                /* If there are annotations left and we have Mule, then we
                   have to do the I/O one emchar at a time so we can
                   determine when to insert the annotation. */
                if (!NILP(*annot)) {
                        Emchar ch;
                        while (pos != nextpos
                               && (ch = Lstream_get_emchar(instr)) != EOF) {
                                if (Lstream_put_emchar(outstr, ch) < 0)
                                        return -1;
                                pos++;
                        }
                } else
#endif                          /* MULE */
                {
                        while (pos != nextpos) {
                                /* Otherwise there is no point to that.  Just go in batches. */
                                int chunk =
                                    min(nextpos - pos, A_WRITE_BATCH_SIZE);

                                chunk = Lstream_read(instr, largebuf, chunk);
                                if (chunk < 0)
                                        return -1;
                                if (chunk == 0) /* EOF */
                                        break;
                                if (Lstream_write(outstr, largebuf, chunk) <
                                    chunk)
                                        return -1;
                                pos += chunk;
                        }
                }
                if (pos == nextpos) {
                        tem = Fcdr(Fcar(*annot));
                        if (STRINGP(tem)) {
                                if (Lstream_write(outstr, XSTRING_DATA(tem),
                                                  XSTRING_LENGTH(tem)) < 0)
                                        return -1;
                        }
                        *annot = Fcdr(*annot);
                } else
                        return 0;
        }
        return -1;
}
\f
DEFUN("verify-visited-file-modtime", Fverify_visited_file_modtime, 1, 1, 0,     /*
Return t if last mod time of BUFFER's visited file matches what BUFFER records.
This means that the file has not been changed since it was visited or saved.
*/
      (buffer))
{
        /* This function can call lisp; GC checked 2000-07-11 ben */
        struct buffer *b;
        struct stat st;
        Lisp_Object handler;

        CHECK_BUFFER(buffer);
        b = XBUFFER(buffer);

        if (!STRINGP(b->filename))
                return Qt;
        if (b->modtime == 0)
                return Qt;

        /* If the file name has special constructs in it,
           call the corresponding file handler.  */
        handler = Ffind_file_name_handler(b->filename,
                                          Qverify_visited_file_modtime);
        if (!NILP(handler))
                return call2(handler, Qverify_visited_file_modtime, buffer);

        if (sxemacs_stat((char *)XSTRING_DATA(b->filename), &st) < 0) {
                /* If the file doesn't exist now and didn't exist before,
                   we say that it isn't modified, provided the error is a tame one.  */
                if (errno == ENOENT || errno == EACCES || errno == ENOTDIR)
                        st.st_mtime = -1;
                else
                        st.st_mtime = 0;
        }
        if (st.st_mtime == b->modtime
            /* If both are positive, accept them if they are off by one second.  */
            || (st.st_mtime > 0 && b->modtime > 0
                && (st.st_mtime == b->modtime + 1
                    || st.st_mtime == b->modtime - 1)))
                return Qt;
        return Qnil;
}

DEFUN("clear-visited-file-modtime", Fclear_visited_file_modtime, 0, 0, 0,       /*
Clear out records of last mod time of visited file.
Next attempt to save will certainly not complain of a discrepancy.
*/
      ())
{
        current_buffer->modtime = 0;
        return Qnil;
}

DEFUN("visited-file-modtime", Fvisited_file_modtime, 0, 0, 0,   /*
Return the current buffer's recorded visited file modification time.
The value is a list of the form (HIGH . LOW), like the time values
that `file-attributes' returns.
*/
      ())
{
        return time_to_lisp((time_t) current_buffer->modtime);
}

DEFUN("set-visited-file-modtime", Fset_visited_file_modtime, 0, 1, 0,   /*
Update buffer's recorded modification time from the visited file's time.
Useful if the buffer was not read from the file normally
or if the file itself has been changed for some known benign reason.
An argument specifies the modification time value to use
\(instead of that of the visited file), in the form of a list
\(HIGH . LOW) or (HIGH LOW).
*/
      (time_list))
{
        /* This function can call lisp */
        if (!NILP(time_list)) {
                time_t the_time;
                lisp_to_time(time_list, &the_time);
                current_buffer->modtime = (int)the_time;
        } else {
                Lisp_Object filename = Qnil;
                struct stat st;
                Lisp_Object handler;
                struct gcpro gcpro1, gcpro2, gcpro3;

                GCPRO3(filename, time_list, current_buffer->filename);
                filename = Fexpand_file_name(current_buffer->filename, Qnil);

                /* If the file name has special constructs in it,
                   call the corresponding file handler.  */
                handler =
                    Ffind_file_name_handler(filename,
                                            Qset_visited_file_modtime);
                UNGCPRO;
                if (!NILP(handler))
                        /* The handler can find the file name the same way we did.  */
                        return call2(handler, Qset_visited_file_modtime, Qnil);
                else if (sxemacs_stat((char *)XSTRING_DATA(filename), &st) >= 0)
                        current_buffer->modtime = st.st_mtime;
        }

        return Qnil;
}
\f
static Lisp_Object
auto_save_error(Lisp_Object condition_object, Lisp_Object ignored)
{
        /* This function can call lisp */
        if (gc_in_progress)
                return Qnil;
        /* Don't try printing an error message after everything is gone! */
        if (preparing_for_armageddon)
                return Qnil;
        clear_echo_area(selected_frame(), Qauto_saving, 1);
        Fding(Qt, Qauto_save_error, Qnil);
        message("Auto-saving...error for %s",
                XSTRING_DATA(current_buffer->name));
        Fsleep_for(make_int(1));
        message("Auto-saving...error!for %s",
                XSTRING_DATA(current_buffer->name));
        Fsleep_for(make_int(1));
        message("Auto-saving...error for %s",
                XSTRING_DATA(current_buffer->name));
        Fsleep_for(make_int(1));
        return Qnil;
}

static Lisp_Object auto_save_1(Lisp_Object ignored)
{
        /* This function can call lisp */
        /* #### I think caller is protecting current_buffer? */
        struct stat st;
        Lisp_Object fn = current_buffer->filename;
        Lisp_Object a = current_buffer->auto_save_file_name;

        if (!STRINGP(a))
                return (Qnil);

        /* Get visited file's mode to become the auto save file's mode.  */
        if (STRINGP(fn) && sxemacs_stat((char *)XSTRING_DATA(fn), &st) >= 0)
                /* But make sure we can overwrite it later!  */
                auto_save_mode_bits = st.st_mode | 0600;
        else
                /* default mode for auto-save files of buffers with no file is
                   readable by owner only.  This may annoy some small number of
                   people, but the alternative removes all privacy from email. */
                auto_save_mode_bits = 0600;

        return
            /* !!#### need to deal with this 'escape-quoted everywhere */
            Fwrite_region_internal(Qnil, Qnil, a, Qnil, Qlambda, Qnil,
#ifdef FILE_CODING
                                   current_buffer->buffer_file_coding_system
#else
                                   Qnil
#endif
            );
}

static Lisp_Object
auto_save_expand_name_error(Lisp_Object condition_object, Lisp_Object ignored)
{
        /* #### this function should spew an error message about not being
           able to open the .saves file. */
        return Qnil;
}

static Lisp_Object auto_save_expand_name(Lisp_Object name)
{
        struct gcpro gcpro1;

        /* note that caller did NOT gc protect name, so we do it. */
        /* #### dmoore - this might not be necessary, if condition_case_1
           protects it.  but I don't think it does. */
        GCPRO1(name);
        RETURN_UNGCPRO(Fexpand_file_name(name, Qnil));
}

static Lisp_Object do_auto_save_unwind(Lisp_Object fd)
{
        close(XINT(fd));
        return (fd);
}

static Lisp_Object do_auto_save_unwind_2(Lisp_Object old_auto_saving)
{
        auto_saving = XINT(old_auto_saving);
        return Qnil;
}

/* Fdo_auto_save() checks whether a GC is in progress when it is called,
   and if so, tries to avoid touching lisp objects.

   The only time that Fdo_auto_save() is called while GC is in progress
   is if we're going down, as a result of an abort() or a kill signal.
   It's fairly important that we generate autosave files in that case!
 */

DEFUN("do-auto-save", Fdo_auto_save, 0, 2, "",  /*
Auto-save all buffers that need it.
This is all buffers that have auto-saving enabled
and are changed since last auto-saved.
Auto-saving writes the buffer into a file
so that your editing is not lost if the system crashes.
This file is not the file you visited; that changes only when you save.
Normally we run the normal hook `auto-save-hook' before saving.

Non-nil first argument means do not print any message if successful.
Non-nil second argument means save only current buffer.
*/
      (no_message, current_only))
{
        /* This function can call lisp */
        struct buffer *b;
        Lisp_Object tail, buf;
        int auto_saved = 0;
        int do_handled_files;
        Lisp_Object oquit = Qnil;
        Lisp_Object listfile = Qnil;
        Lisp_Object old;
        int listdesc = -1;
        int speccount = specpdl_depth();
        struct gcpro gcpro1, gcpro2, gcpro3;

        XSETBUFFER(old, current_buffer);
        GCPRO3(oquit, listfile, old);
        check_quit();           /* make Vquit_flag accurate */
        /* Ordinarily don't quit within this function,
           but don't make it impossible to quit (in case we get hung in I/O).  */
        oquit = Vquit_flag;
        Vquit_flag = Qnil;

        /* No further GCPRO needed, because (when it matters) all Lisp_Object
           variables point to non-strings reached from Vbuffer_alist.  */

        if (minibuf_level != 0 || preparing_for_armageddon)
                no_message = Qt;

        run_hook(Qauto_save_hook);

        if (STRINGP(Vauto_save_list_file_name))
                listfile = condition_case_1(Qt,
                                            auto_save_expand_name,
                                            Vauto_save_list_file_name,
                                            auto_save_expand_name_error, Qnil);

        /* Make sure auto_saving is reset. */
        record_unwind_protect(do_auto_save_unwind_2, make_int(auto_saving));

        auto_saving = 1;

        /* First, save all files which don't have handlers.  If Emacs is
           crashing, the handlers may tweak what is causing Emacs to crash
           in the first place, and it would be a shame if Emacs failed to
           autosave perfectly ordinary files because it couldn't handle some
           ange-ftp'd file.  */
        for (do_handled_files = 0; do_handled_files < 2; do_handled_files++) {
                for (tail = Vbuffer_alist; CONSP(tail); tail = XCDR(tail)) {
                        buf = XCDR(XCAR(tail));
                        b = XBUFFER(buf);

                        if (!NILP(current_only)
                            && b != current_buffer)
                                continue;

                        /* Don't auto-save indirect buffers.
                           The base buffer takes care of it.  */
                        if (b->base_buffer)
                                continue;

                        /* Check for auto save enabled
                           and file changed since last auto save
                           and file changed since last real save.  */
                        if (STRINGP(b->auto_save_file_name)
                            && BUF_SAVE_MODIFF(b) < BUF_MODIFF(b)
                            && b->auto_save_modified < BUF_MODIFF(b)
                            /* -1 means we've turned off autosaving for a while--see below.  */
                            && XINT(b->saved_size) >= 0
                            && (do_handled_files
                                ||
                                NILP(Ffind_file_name_handler
                                     (b->auto_save_file_name,
                                      Qwrite_region)))) {
                                EMACS_TIME before_time, after_time;

                                EMACS_GET_TIME(before_time);
                                /* If we had a failure, don't try again for 20 minutes.  */
                                if (!preparing_for_armageddon
                                    && b->auto_save_failure_time >= 0
                                    && (EMACS_SECS(before_time) -
                                        b->auto_save_failure_time < 1200))
                                        continue;

                                if (!preparing_for_armageddon &&
                                    (XINT(b->saved_size) * 10
                                     > (BUF_Z(b) - BUF_BEG(b)) * 13)
                                    /* A short file is likely to change a large fraction;
                                       spare the user annoying messages.  */
                                    && XINT(b->saved_size) > 5000
                                    /* These messages are frequent and annoying for `*mail*'.  */
                                    && !NILP(b->filename)
                                    && NILP(no_message)
                                    && disable_auto_save_when_buffer_shrinks) {
                                        /* It has shrunk too much; turn off auto-saving here.
                                           Unless we're about to crash, in which case auto-save it
                                           anyway.
                                         */
                                        message
                                            ("Buffer %s has shrunk a lot; auto save turned off there",
                                             XSTRING_DATA(b->name));
                                        /* Turn off auto-saving until there's a real save,
                                           and prevent any more warnings.  */
                                        b->saved_size = make_int(-1);
                                        if (!gc_in_progress)
                                                Fsleep_for(make_int(1));
                                        continue;
                                }
                                set_buffer_internal(b);
                                if (!auto_saved && NILP(no_message)) {
                                        static const unsigned char *msg
                                            =
                                            (const unsigned char *)
                                            "Auto-saving...";
                                        echo_area_message(selected_frame(), msg,
                                                          Qnil, 0,
                                                          strlen((const char *)
                                                                 msg),
                                                          Qauto_saving);
                                }

                                /* Open the auto-save list file, if necessary.
                                   We only do this now so that the file only exists
                                   if we actually auto-saved any files. */
                                if (!auto_saved && !inhibit_auto_save_session
                                    && !NILP(Vauto_save_list_file_prefix)
                                    && STRINGP(listfile) && listdesc < 0) {
                                        listdesc =
                                            open((char *)XSTRING_DATA(listfile),
                                                 O_WRONLY | O_TRUNC | O_CREAT |
                                                 OPEN_BINARY, CREAT_MODE);

                                        /* Arrange to close that file whether or not we get
                                           an error. */
                                        if (listdesc >= 0)
                                                record_unwind_protect
                                                    (do_auto_save_unwind,
                                                     make_int(listdesc));
                                }

                                /* Record all the buffers that we are auto-saving in
                                   the special file that lists them.  For each of
                                   these buffers, record visited name (if any) and
                                   auto save name.  */
                                if (listdesc >= 0) {
                                        const Extbyte *auto_save_file_name_ext;
                                        Extcount auto_save_file_name_ext_len;

                                        TO_EXTERNAL_FORMAT(LISP_STRING,
                                                           b->
                                                           auto_save_file_name,
                                                           ALLOCA,
                                                           (auto_save_file_name_ext,
                                                            auto_save_file_name_ext_len),
                                                           Qfile_name);
                                        if (!NILP(b->filename)) {
                                                const Extbyte *filename_ext;
                                                Extcount filename_ext_len;

                                                TO_EXTERNAL_FORMAT(LISP_STRING,
                                                                   b->filename,
                                                                   ALLOCA,
                                                                   (filename_ext,
                                                                    filename_ext_len),
                                                                   Qfile_name);
                                                write(listdesc, filename_ext,
                                                      filename_ext_len);
                                        }
                                        write(listdesc, "\n", 1);
                                        write(listdesc, auto_save_file_name_ext,
                                              auto_save_file_name_ext_len);
                                        write(listdesc, "\n", 1);
                                }

                                /* dmoore - In a bad scenario we've set b=XBUFFER(buf)
                                   based on values in Vbuffer_alist.  auto_save_1 may
                                   cause lisp handlers to run.  Those handlers may kill
                                   the buffer and then GC.  Since the buffer is killed,
                                   it's no longer in Vbuffer_alist so it might get reaped
                                   by the GC.  We also need to protect tail. */
                                /* #### There is probably a lot of other code which has
                                   pointers into buffers which may get blown away by
                                   handlers. */
                                {
                                        struct gcpro ngcpro1, ngcpro2;
                                        NGCPRO2(buf, tail);
                                        condition_case_1(Qt,
                                                         auto_save_1, Qnil,
                                                         auto_save_error, Qnil);
                                        NUNGCPRO;
                                }
                                /* Handler killed our saved current-buffer!  Pick any. */
                                if (!BUFFER_LIVE_P(XBUFFER(old)))
                                        XSETBUFFER(old, current_buffer);

                                set_buffer_internal(XBUFFER(old));
                                auto_saved++;

                                /* Handler killed their own buffer! */
                                if (!BUFFER_LIVE_P(b))
                                        continue;

                                b->auto_save_modified = BUF_MODIFF(b);
                                b->saved_size = make_int(BUF_SIZE(b));
                                EMACS_GET_TIME(after_time);
                                /* If auto-save took more than 60 seconds,
                                   assume it was an NFS failure that got a timeout.  */
                                if (EMACS_SECS(after_time) -
                                    EMACS_SECS(before_time) > 60)
                                        b->auto_save_failure_time =
                                            EMACS_SECS(after_time);
                        }
                }
        }

        /* Prevent another auto save till enough input events come in.  */
        if (auto_saved)
                record_auto_save();

        /* If we didn't save anything into the listfile, remove the old
           one because nothing needed to be auto-saved.  Do this afterwards
           rather than before in case we get a crash attempting to autosave
           (in that case we'd still want the old one around). */
        if (listdesc < 0 && !auto_saved && STRINGP(listfile))
                unlink((char *)XSTRING_DATA(listfile));

        if (listdesc >= 0)
                close(listdesc);

        /* Show "...done" only if the echo area would otherwise be empty. */
        if (auto_saved && NILP(no_message)
            && NILP(clear_echo_area(selected_frame(), Qauto_saving, 0))) {
                static const unsigned char *msg
                    = (const unsigned char *)"Auto-saving...done";
                echo_area_message(selected_frame(), msg, Qnil, 0,
                                  strlen((const char *)msg), Qauto_saving);
        }

        Vquit_flag = oquit;

        RETURN_UNGCPRO(unbind_to(speccount, Qnil));
}

DEFUN("set-buffer-auto-saved", Fset_buffer_auto_saved, 0, 0, 0, /*
Mark current buffer as auto-saved with its current text.
No auto-save file will be written until the buffer changes again.
*/
      ())
{
        current_buffer->auto_save_modified = BUF_MODIFF(current_buffer);
        current_buffer->saved_size = make_int(BUF_SIZE(current_buffer));
        current_buffer->auto_save_failure_time = -1;
        return Qnil;
}

DEFUN("clear-buffer-auto-save-failure", Fclear_buffer_auto_save_failure, 0, 0, 0,       /*
Clear any record of a recent auto-save failure in the current buffer.
*/
      ())
{
        current_buffer->auto_save_failure_time = -1;
        return Qnil;
}

DEFUN("recent-auto-save-p", Frecent_auto_save_p, 0, 0, 0,       /*
Return t if buffer has been auto-saved since last read in or saved.
*/
      ())
{
        return (BUF_SAVE_MODIFF(current_buffer) <
                current_buffer->auto_save_modified) ? Qt : Qnil;
}
\f
/************************************************************************/
/*                            initialization                            */
/************************************************************************/

void syms_of_fileio(void)
{
        defsymbol(&Qexpand_file_name, "expand-file-name");
        defsymbol(&Qfile_truename, "file-truename");
        defsymbol(&Qsubstitute_in_file_name, "substitute-in-file-name");
        defsymbol(&Qdirectory_file_name, "directory-file-name");
        defsymbol(&Qfile_dirname, "file-dirname");
        defsymbol(&Qfile_basename, "file-basename");
        defsymbol(&Qfile_name_directory, "file-name-directory");
        defsymbol(&Qfile_name_nondirectory, "file-name-nondirectory");
        defsymbol(&Qunhandled_file_name_directory,
                  "unhandled-file-name-directory");
        defsymbol(&Qfile_name_as_directory, "file-name-as-directory");
        defsymbol(&Qcopy_file, "copy-file");
        defsymbol(&Qmake_directory_internal, "make-directory-internal");
        defsymbol(&Qdelete_directory, "delete-directory");
        defsymbol(&Qdelete_file, "delete-file");
        defsymbol(&Qrename_file, "rename-file");
        defsymbol(&Qadd_name_to_file, "add-name-to-file");
        defsymbol(&Qmake_symbolic_link, "make-symbolic-link");
        defsymbol(&Qfile_exists_p, "file-exists-p");
        defsymbol(&Qfile_executable_p, "file-executable-p");
        defsymbol(&Qfile_readable_p, "file-readable-p");
        defsymbol(&Qfile_symlink_p, "file-symlink-p");
        defsymbol(&Qfile_writable_p, "file-writable-p");
        defsymbol(&Qfile_directory_p, "file-directory-p");
        defsymbol(&Qfile_regular_p, "file-regular-p");
        defsymbol(&Qfile_accessible_directory_p, "file-accessible-directory-p");
        defsymbol(&Qfile_modes, "file-modes");
        defsymbol(&Qset_file_modes, "set-file-modes");
        defsymbol(&Qfile_newer_than_file_p, "file-newer-than-file-p");
        defsymbol(&Qinsert_file_contents, "insert-file-contents");
        defsymbol(&Qwrite_region, "write-region");
        defsymbol(&Qverify_visited_file_modtime, "verify-visited-file-modtime");
        defsymbol(&Qset_visited_file_modtime, "set-visited-file-modtime");
        defsymbol(&Qcar_less_than_car, "car-less-than-car");    /* Vomitous! */

        defsymbol(&Qauto_save_hook, "auto-save-hook");
        defsymbol(&Qauto_save_error, "auto-save-error");
        defsymbol(&Qauto_saving, "auto-saving");

        defsymbol(&Qformat_decode, "format-decode");
        defsymbol(&Qformat_annotate_function, "format-annotate-function");

        defsymbol(&Qcompute_buffer_file_truename,
                  "compute-buffer-file-truename");
        DEFERROR_STANDARD(Qfile_error, Qio_error);
        DEFERROR_STANDARD(Qfile_already_exists, Qfile_error);

        DEFSUBR(Ffind_file_name_handler);

        DEFSUBR(Ffile_name_directory);
        DEFSUBR(Ffile_name_nondirectory);
        DEFSUBR(Ffile_basename);
        DEFSUBR(Ffile_dirname);
        DEFSUBR(Funhandled_file_name_directory);
        DEFSUBR(Ffile_name_as_directory);
        DEFSUBR(Fdirectory_file_name);
        DEFSUBR(Fmake_temp_name);
        DEFSUBR(Fexpand_file_name);
        DEFSUBR(Ffile_truename);
        DEFSUBR(Fsubstitute_in_file_name);
        DEFSUBR(Fcopy_file);
        DEFSUBR(Fmake_directory_internal);
        DEFSUBR(Fdelete_directory);
        DEFSUBR(Fdelete_file);
        DEFSUBR(Frename_file);
        DEFSUBR(Fadd_name_to_file);
        DEFSUBR(Fmake_symbolic_link);
#ifdef HPUX_NET
        DEFSUBR(Fsysnetunam);
#endif                          /* HPUX_NET */
        DEFSUBR(Ffile_name_absolute_p);
        DEFSUBR(Ffile_exists_p);
        DEFSUBR(Ffile_executable_p);
        DEFSUBR(Ffile_readable_p);
        DEFSUBR(Ffile_writable_p);
        DEFSUBR(Ffile_symlink_p);
        DEFSUBR(Ffile_directory_p);
        DEFSUBR(Ffile_accessible_directory_p);
        DEFSUBR(Ffile_regular_p);
        DEFSUBR(Ffile_modes);
        DEFSUBR(Fset_file_modes);
        DEFSUBR(Fset_default_file_modes);
        DEFSUBR(Fdefault_file_modes);
        DEFSUBR(Funix_sync);
        DEFSUBR(Ffile_newer_than_file_p);
        DEFSUBR(Finsert_file_contents_internal);
        DEFSUBR(Fwrite_region_internal);
        DEFSUBR(Fcar_less_than_car);    /* Vomitous! */
        DEFSUBR(Fcdr_less_than_cdr);    /* Yeah oh yeah bucko .... */
        DEFSUBR(Fverify_visited_file_modtime);
        DEFSUBR(Fclear_visited_file_modtime);
        DEFSUBR(Fvisited_file_modtime);
        DEFSUBR(Fset_visited_file_modtime);

        DEFSUBR(Fdo_auto_save);
        DEFSUBR(Fset_buffer_auto_saved);
        DEFSUBR(Fclear_buffer_auto_save_failure);
        DEFSUBR(Frecent_auto_save_p);
}

void vars_of_fileio(void)
{
        DEFVAR_LISP("auto-save-file-format", &Vauto_save_file_format    /*
*Format in which to write auto-save files.
Should be a list of symbols naming formats that are defined in `format-alist'.
If it is t, which is the default, auto-save files are written in the
same format as a regular save would use.
                                                                         */ );
        Vauto_save_file_format = Qt;

        DEFVAR_LISP("file-name-handler-alist", &Vfile_name_handler_alist        /*
*Alist of elements (REGEXP . HANDLER) for file names handled specially.
If a file name matches REGEXP, then all I/O on that file is done by calling
HANDLER.

The first argument given to HANDLER is the name of the I/O primitive
to be handled; the remaining arguments are the arguments that were
passed to that primitive.  For example, if you do
(file-exists-p FILENAME)
and FILENAME is handled by HANDLER, then HANDLER is called like this:
(funcall HANDLER 'file-exists-p FILENAME)
The function `find-file-name-handler' checks this list for a handler
for its argument.
                                                                                 */ );
        Vfile_name_handler_alist = Qnil;

        DEFVAR_LISP("after-insert-file-functions", &Vafter_insert_file_functions        /*
A list of functions to be called at the end of `insert-file-contents'.
Each is passed one argument, the number of bytes inserted.  It should return
the new byte count, and leave point the same.  If `insert-file-contents' is
intercepted by a handler from `file-name-handler-alist', that handler is
responsible for calling the after-insert-file-functions if appropriate.
                                                                                         */ );
        Vafter_insert_file_functions = Qnil;

        DEFVAR_LISP("write-region-annotate-functions", &Vwrite_region_annotate_functions        /*
A list of functions to be called at the start of `write-region'.
Each is passed two arguments, START and END, as for `write-region'.
It should return a list of pairs (POSITION . STRING) of strings to be
effectively inserted at the specified positions of the file being written
\(1 means to insert before the first byte written).  The POSITIONs must be
sorted into increasing order.  If there are several functions in the list,
the several lists are merged destructively.
                                                                                                 */ );
        Vwrite_region_annotate_functions = Qnil;

        DEFVAR_LISP("write-region-annotations-so-far", &Vwrite_region_annotations_so_far        /*
When an annotation function is called, this holds the previous annotations.
These are the annotations made by other annotation functions
that were already called.  See also `write-region-annotate-functions'.
                                                                                                 */ );
        Vwrite_region_annotations_so_far = Qnil;

        DEFVAR_LISP("inhibit-file-name-handlers", &Vinhibit_file_name_handlers  /*
A list of file name handlers that temporarily should not be used.
This applies only to the operation `inhibit-file-name-operation'.
                                                                                 */ );
        Vinhibit_file_name_handlers = Qnil;

        DEFVAR_LISP("inhibit-file-name-operation", &Vinhibit_file_name_operation        /*
The operation for which `inhibit-file-name-handlers' is applicable.
                                                                                         */ );
        Vinhibit_file_name_operation = Qnil;

        DEFVAR_LISP("auto-save-list-file-name", &Vauto_save_list_file_name      /*
File name in which we write a list of all auto save file names.
                                                                                 */ );
        Vauto_save_list_file_name = Qnil;

        DEFVAR_LISP("auto-save-list-file-prefix", &Vauto_save_list_file_prefix  /*
Prefix for generating auto-save-list-file-name.
Emacs's pid and the system name will be appended to
this prefix to create a unique file name.
                                                                                 */ );
        Vauto_save_list_file_prefix = build_string("~/.saves-");

        DEFVAR_BOOL("inhibit-auto-save-session", &inhibit_auto_save_session     /*
When non-nil, inhibit auto save list file creation.
                                                                                 */ );
        inhibit_auto_save_session = 0;

        DEFVAR_BOOL("disable-auto-save-when-buffer-shrinks", &disable_auto_save_when_buffer_shrinks     /*
If non-nil, auto-saving is disabled when a buffer shrinks too much.
This is to prevent you from losing your edits if you accidentally
delete a large chunk of the buffer and don't notice it until too late.
Saving the buffer normally turns auto-save back on.
                                                                                                         */ );
        disable_auto_save_when_buffer_shrinks = 1;

        DEFVAR_LISP("directory-sep-char", &Vdirectory_sep_char  /*
Directory separator character for built-in functions that return file names.
The value should be either ?/ or ?\\ (any other value is treated as ?\\).
This variable affects the built-in functions only on Windows,
on other platforms, it is initialized so that Lisp code can find out
what the normal separator is.
                                                                 */ );
        Vdirectory_sep_char = make_char('/');

        reinit_vars_of_fileio();
}

void reinit_vars_of_fileio(void)
{
        /* We want temp_name_rand to be initialized to a value likely to be
           unique to the process, not to the executable.  The danger is that
           two different SXEmacs processes using the same binary on different
           machines creating temp files in the same directory will be
           unlucky enough to have the same pid.  If we randomize using
           process startup time, then in practice they will be unlikely to
           collide. We use the microseconds field so that scripts that start
           simultaneous SXEmacs processes on multiple machines will have less
           chance of collision.  */
        {
                EMACS_TIME thyme;

                EMACS_GET_TIME(thyme);
                temp_name_rand =
                    (unsigned int)(EMACS_SECS(thyme) ^ EMACS_USECS(thyme));
        }
}