elf/sln.c

   1 /* `sln' program to create symbolic links between files.
   2    Copyright (C) 1998, 1999, 2001, 2009 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifdef HAVE_CONFIG_H
  20 # include "config.h"
  21 #endif
  22
  23 #include <error.h>
  24 #include <errno.h>
  25 #include <libintl.h>
  26 #include <locale.h>
  27 #include <sys/types.h>
  28 #include <sys/stat.h>
  29 #include <unistd.h>
  30 #include <errno.h>
  31 #include <ctype.h>
  32 #include <stdio.h>
  33 #include <string.h>
  34 #include <limits.h>
  35
  36 #include "../version.h"
  37
  38 #define PACKAGE _libc_intl_domainname
  39
  40 #if !defined S_ISDIR && defined S_IFDIR
  41 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
  42 #endif
  43
  44 static int makesymlink (const char *src, const char *dest);
  45 static int makesymlinks (const char *file);
  46 static void usage (void);
  47
  48 int
  49 main (int argc, char **argv)
  50 {
  51   /* Set locale via LC_ALL.  */
  52   setlocale (LC_ALL, "");
  53
  54   /* Set the text message domain.  */
  55   textdomain (PACKAGE);
  56
  57   switch (argc)
  58     {
  59     case 2:
  60       if (strcmp (argv[1], "--version") == 0) {
  61         printf ("sln (GNU libc) %s\n", VERSION);
  62         return 0;
  63       } else if (strcmp (argv[1], "--help") == 0) {
  64         usage ();
  65         return 0;
  66       }
  67       return makesymlinks (argv [1]);
  68       break;
  69
  70     case 3:
  71       return makesymlink (argv [1], argv [2]);
  72       break;
  73
  74     default:
  75       usage ();
  76       return 1;
  77       break;
  78     }
  79 }
  80
  81 static void
  82 usage (void)
  83 {
  84   printf (_("Usage: sln src dest|file\n\n"));
  85   fputs (_("For bug reporting instructions, please see:\n\
  86 <http://www.gnu.org/software/libc/bugs.html>.\n"), stdout);
  87 }
  88
  89 static int
  90 makesymlinks (file)
  91      const char *file;
  92 {
  93 #ifndef PATH_MAX
  94 #define PATH_MAX 4095
  95 #endif
  96   char *buffer = NULL;
  97   size_t bufferlen = 0;
  98   int ret;
  99   int lineno;
 100   FILE *fp;
 101
 102   if (strcmp (file, "-") == 0)
 103     fp = stdin;
 104   else
 105     {
 106       fp = fopen (file, "r");
 107       if (fp == NULL)
 108         {
 109           fprintf (stderr, _("%s: file open error: %m\n"), file);
 110           return 1;
 111         }
 112     }
 113
 114   ret = 0;
 115   lineno = 0;
 116   while (!feof_unlocked (fp))
 117     {
 118       ssize_t n = getline (&buffer, &bufferlen, fp);
 119       char *src;
 120       char *dest;
 121       char *cp = buffer;
 122
 123       if (n < 0)
 124         break;
 125       if (buffer[n - 1] == '\n')
 126         buffer[n - 1] = '\0';
 127
 128       ++lineno;
 129       while (isspace (*cp))
 130         ++cp;
 131       if (*cp == '\0')
 132         /* Ignore empty lines.  */
 133         continue;
 134       src = cp;
 135
 136       do
 137         ++cp;
 138       while (*cp != '\0' && ! isspace (*cp));
 139       if (*cp != '\0')
 140         *cp++ = '\0';
 141
 142       while (isspace (*cp))
 143         ++cp;
 144       if (*cp == '\0')
 145         {
 146           fprintf (stderr, _("No target in line %d\n"), lineno);
 147           ret = 1;
 148           continue;
 149         }
 150       dest = cp;
 151
 152       do
 153         ++cp;
 154       while (*cp != '\0' && ! isspace (*cp));
 155       if (*cp != '\0')
 156         *cp++ = '\0';
 157
 158       ret |= makesymlink (src, dest);
 159     }
 160   fclose (fp);
 161
 162   return ret;
 163 }
 164
 165 static int
 166 makesymlink (src, dest)
 167      const char *src;
 168      const char *dest;
 169 {
 170   struct stat stats;
 171   const char *error;
 172
 173   /* Destination must not be a directory. */
 174   if (lstat (dest, &stats) == 0)
 175     {
 176       if (S_ISDIR (stats.st_mode))
 177         {
 178           fprintf (stderr, _("%s: destination must not be a directory\n"),
 179                    dest);
 180           return 1;
 181         }
 182       else if (unlink (dest) && errno != ENOENT)
 183         {
 184           fprintf (stderr, _("%s: failed to remove the old destination\n"),
 185                    dest);
 186           return 1;
 187         }
 188     }
 189   else if (errno != ENOENT)
 190     {
 191       error = strerror (errno);
 192       fprintf (stderr, _("%s: invalid destination: %s\n"), dest, error);
 193       return -1;
 194     }
 195
 196 #ifdef S_ISLNK
 197   if (symlink (src, dest) == 0)
 198 #else
 199   if (link (src, dest) == 0)
 200 #endif
 201     {
 202       /* Destination must exist by now. */
 203       if (access (dest, F_OK))
 204         {
 205           error = strerror (errno);
 206           unlink (dest);
 207           fprintf (stderr, _("Invalid link from \"%s\" to \"%s\": %s\n"),
 208                    src, dest, error);
 209           return 1;
 210         }
 211       return 0;
 212     }
 213   else
 214     {
 215       error = strerror (errno);
 216       fprintf (stderr, _("Invalid link from \"%s\" to \"%s\": %s\n"),
 217                src, dest, error);
 218       return 1;
 219     }
 220 }