fopen.c

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Hash : 26fd3545
Author :
Date : 2025-09-16T23:08:01

stringeq: prefer streq to strcmp in other modules

* lib/acl-internal.c, lib/argmatch.c, lib/argp-help.c:
* lib/argp-parse.c, lib/bcp47.c, lib/c32_get_mapping.c:
* lib/c32_get_type_test.c, lib/concat-filename.c:
* lib/cpu-supports.h, lib/dfa.c, lib/duplocale.c, lib/exclude.c:
* lib/findprog-in.c, lib/findprog.c, lib/fopen.c, lib/freopen.c:
* lib/fts.c, lib/gen-uni-tables.c, lib/getfilecon.c:
* lib/getlogin.c, lib/getugroups.c, lib/hard-locale.c:
* lib/hashcode-named-file.c, lib/hashkey-string.c:
* lib/iconv_open.c, lib/idcache.c, lib/lc-charset-unicode.c:
* lib/localcharset.c, lib/localename-environ.c:
* lib/localename-unsafe.c, lib/mbs_endswith.c, lib/mountlist.c:
* lib/newlocale.c, lib/nl_langinfo.c, lib/nproc.c, lib/open.c:
* lib/os2-spawn.c, lib/parse-datetime.y, lib/popen.c:
* lib/progreloc.c, lib/propername.c, lib/pt_chown.c, lib/putenv.c:
* lib/qcopy-acl.c, lib/readutmp.c, lib/rpmatch.c:
* lib/setlocale-fixes.c, lib/setlocale.c, lib/sig2str.c:
* lib/spawni.c, lib/stat.c, lib/str_endswith.c, lib/streq.h:
* lib/striconveha.c, lib/struniq.h, lib/supersede.c:
* lib/time_rz.c, lib/unicodeio.c, lib/vasnprintf.c:
* lib/vc-mtime.c, lib/wctrans-impl.h, lib/wctype-impl.h:
Prefer streq to strcmp when either will do.
Do not make this change to files shared with glibc.
Do not make the change to test files, at least not for now.
* lib/gen-uni-tables.c (streq): New static function, in same style.
* modules/acl-permissions, modules/argp, modules/c32_get_mapping:
* modules/c32_get_type_test, modules/concat-filename:
* modules/cpu-supports, modules/dfa, modules/duplocale:
* modules/exclude, modules/findprog, modules/findprog-in:
* modules/fopen, modules/fopen-gnu, modules/freopen, modules/fts:
* modules/getlocalename_l-simple, modules/getlocalename_l-unsafe:
* modules/getlogin, modules/getugroups, modules/hard-locale:
* modules/hashcode-named-file, modules/hashkey-string:
* modules/iconv_open, modules/idcache, modules/localcharset:
* modules/localename, modules/localename-unsafe:
* modules/mbs_endswith, modules/mountlist, modules/newlocale:
* modules/nl_langinfo, modules/nproc, modules/open:
* modules/parse-datetime, modules/popen:
* modules/posix_spawn-internal, modules/propername:
* modules/pt_chown, modules/putenv-gnu, modules/qcopy-acl:
* modules/rpmatch, modules/selinux-h, modules/setenv:
* modules/setlocale, modules/setlocale-fixes, modules/sig2str:
* modules/spawn-pipe, modules/stat, modules/str_endswith:
* modules/streq, modules/striconveha, modules/supersede:
* modules/time_rz, modules/uchar-h, modules/unicodeio:
* modules/uniconv/base, modules/wctrans, modules/wctype:
(Depends-on): Add stringeq.

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lib/fopen.c

/* Open a stream to a file.
   Copyright (C) 2007-2025 Free Software Foundation, Inc.

   This file is free software: you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of the
   License, or (at your option) any later version.

   This file 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 Lesser General Public License for more details.

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

/* Written by Bruno Haible <bruno@clisp.org>, 2007.  */

/* If the user's config.h happens to include <stdio.h>, let it include only
   the system's <stdio.h> here, so that orig_fopen doesn't recurse to
   rpl_fopen.  */
#define _GL_SKIP_GNULIB_STDIO_H
#include <config.h>

/* Get the original definition of fopen.  It might be defined as a macro.  */
#include <stdio.h>
#undef _GL_SKIP_GNULIB_STDIO_H

static FILE *
orig_fopen (const char *filename, const char *mode)
{
  return fopen (filename, mode);
}

/* Specification.  */
#include <stdio.h>

#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>

FILE *
rpl_fopen (const char *filename, const char *mode)
{
  int open_direction;
  int open_flags;
#if GNULIB_FOPEN_GNU
  bool open_flags_gnu;
# define BUF_SIZE 80
  char fdopen_mode_buf[BUF_SIZE + 1];
#endif

#if defined _WIN32 && ! defined __CYGWIN__
  if (streq (filename, "/dev/null"))
    filename = "NUL";
#endif

  /* Parse the mode.  */
  open_direction = 0;
  open_flags = 0;
#if GNULIB_FOPEN_GNU
  open_flags_gnu = false;
#endif
  {
    const char *p = mode;
#if GNULIB_FOPEN_GNU
    char *q = fdopen_mode_buf;
#endif

    for (; *p != '\0'; p++)
      {
        switch (*p)
          {
          case 'r':
            open_direction = O_RDONLY;
#if GNULIB_FOPEN_GNU
            if (q < fdopen_mode_buf + BUF_SIZE)
              *q++ = *p;
#endif
            continue;
          case 'w':
            open_direction = O_WRONLY;
            open_flags |= O_CREAT | O_TRUNC;
#if GNULIB_FOPEN_GNU
            if (q < fdopen_mode_buf + BUF_SIZE)
              *q++ = *p;
#endif
            continue;
          case 'a':
            open_direction = O_WRONLY;
            open_flags |= O_CREAT | O_APPEND;
#if GNULIB_FOPEN_GNU
            if (q < fdopen_mode_buf + BUF_SIZE)
              *q++ = *p;
#endif
            continue;
          case 'b':
            /* While it is non-standard, O_BINARY is guaranteed by
               gnulib <fcntl.h>.  We can also assume that orig_fopen
               supports the 'b' flag.  */
            open_flags |= O_BINARY;
#if GNULIB_FOPEN_GNU
            if (q < fdopen_mode_buf + BUF_SIZE)
              *q++ = *p;
#endif
            continue;
          case '+':
            open_direction = O_RDWR;
#if GNULIB_FOPEN_GNU
            if (q < fdopen_mode_buf + BUF_SIZE)
              *q++ = *p;
#endif
            continue;
#if GNULIB_FOPEN_GNU
          case 'x':
            open_flags |= O_EXCL;
            open_flags_gnu = true;
            continue;
          case 'e':
            open_flags |= O_CLOEXEC;
            open_flags_gnu = true;
            continue;
#endif
          default:
            break;
          }
#if GNULIB_FOPEN_GNU
        /* The rest of the mode string can be a platform-dependent extension.
           Copy it unmodified.  */
        {
          size_t len = strlen (p);
          if (len > fdopen_mode_buf + BUF_SIZE - q)
            len = fdopen_mode_buf + BUF_SIZE - q;
          memcpy (q, p, len);
          q += len;
        }
#endif
        break;
      }
#if GNULIB_FOPEN_GNU
    *q = '\0';
#endif
  }

#if FOPEN_TRAILING_SLASH_BUG
  /* Fail if the mode requires write access and the filename ends in a slash,
     as POSIX says such a filename must name a directory
     <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13>:
       "A pathname that contains at least one non-<slash> character and that
        ends with one or more trailing <slash> characters shall not be resolved
        successfully unless the last pathname component before the trailing
        <slash> characters names an existing directory"
     If the named file already exists as a directory, then if a mode that
     requires write access is specified, fopen() must fail because POSIX
     <https://pubs.opengroup.org/onlinepubs/9699919799/functions/fopen.html>
     says that it fails with errno = EISDIR in this case.
     If the named file does not exist or does not name a directory, then
     fopen() must fail since the file does not contain a '.' directory.  */
  {
    size_t len = strlen (filename);
    if (len > 0 && filename[len - 1] == '/')
      {
        int fd;
        struct stat statbuf;
        FILE *fp;

        if (open_direction != O_RDONLY)
          {
            errno = EISDIR;
            return NULL;
          }

        fd = open (filename, open_direction | open_flags,
                   S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
        if (fd < 0)
          return NULL;

        if (fstat (fd, &statbuf) >= 0 && !S_ISDIR (statbuf.st_mode))
          {
            close (fd);
            errno = ENOTDIR;
            return NULL;
          }

# if GNULIB_FOPEN_GNU
        fp = fdopen (fd, fdopen_mode_buf);
# else
        fp = fdopen (fd, mode);
# endif
        if (fp == NULL)
          {
            int saved_errno = errno;
            close (fd);
            errno = saved_errno;
          }
        return fp;
      }
  }
#endif

#if GNULIB_FOPEN_GNU
  if (open_flags_gnu)
    {
      int fd;
      FILE *fp;

      fd = open (filename, open_direction | open_flags,
                 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
      if (fd < 0)
        return NULL;

      fp = fdopen (fd, fdopen_mode_buf);
      if (fp == NULL)
        {
          int saved_errno = errno;
          close (fd);
          errno = saved_errno;
        }
      return fp;
    }
#endif

  /* open_direction is sometimes used, sometimes unused.
     Silence gcc's warning about this situation.  */
  (void) open_direction;

  return orig_fopen (filename, mode);
}

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kc3-lang/gnulib/lib/fopen.c

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lib/fopen.c