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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifdef HAVE_CONFIG_H
  21 # include "config.h"
  22 #endif
  23
  24 #include <error.h>
  25 #include <errno.h>
  26 #include <libintl.h>
  27 #include <locale.h>
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <unistd.h>
  31 #include <errno.h>
  32 #include <ctype.h>
  33 #include <stdio.h>
  34 #include <string.h>
  35 #include <limits.h>
  36
  37 #include "../version.h"
  38
  39 #define PACKAGE _libc_intl_domainname
  40
  41 #if !defined S_ISDIR && defined S_IFDIR
  42 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
  43 #endif
  44
  45 static int makesymlink (const char *src, const char *dest);
  46 static int makesymlinks (const char *file);
  47 static void usage (void);
  48
  49 int
  50 main (int argc, char **argv)
  51 {
  52   /* Set locale via LC_ALL.  */
  53   setlocale (LC_ALL, "");
  54
  55   /* Set the text message domain.  */
  56   textdomain (PACKAGE);
  57
  58   switch (argc)
  59     {
  60     case 2:
  61       if (strcmp (argv[1], "--version") == 0) {
  62         printf ("sln (GNU libc) %s\n", VERSION);
  63         return 0;
  64       } else if (strcmp (argv[1], "--help") == 0) {
  65         usage ();
  66         return 0;
  67       }
  68       return makesymlinks (argv [1]);
  69       break;
  70
  71     case 3:
  72       return makesymlink (argv [1], argv [2]);
  73       break;
  74
  75     default:
  76       usage ();
  77       return 1;
  78       break;
  79     }
  80 }
  81
  82 static void
  83 usage (void)
  84 {
  85   printf (_("Usage: sln src dest|file\n\n"));
  86   fputs (_("For bug reporting instructions, please see:\n\
  87 <http://www.gnu.org/software/libc/bugs.html>.\n"), stdout);
  88 }
  89
  90 static int
  91 makesymlinks (file)
  92      const char *file;
  93 {
  94 #ifndef PATH_MAX
  95 #define PATH_MAX 4095
  96 #endif
  97   char *buffer = NULL;
  98   size_t bufferlen = 0;
  99   int ret;
 100   int lineno;
 101   FILE *fp;
 102
 103   if (strcmp (file, "-") == 0)
 104     fp = stdin;
 105   else
 106     {
 107       fp = fopen (file, "r");
 108       if (fp == NULL)
 109         {
 110           fprintf (stderr, _("%s: file open error: %m\n"), file);
 111           return 1;
 112         }
 113     }
 114
 115   ret = 0;
 116   lineno = 0;
 117   while (!feof_unlocked (fp))
 118     {
 119       ssize_t n = getline (&buffer, &bufferlen, fp);
 120       char *src;
 121       char *dest;
 122       char *cp = buffer;
 123
 124       if (n < 0)
 125         break;
 126       if (buffer[n - 1] == '\n')
 127         buffer[n - 1] = '\0';
 128
 129       ++lineno;
 130       while (isspace (*cp))
 131         ++cp;
 132       if (*cp == '\0')
 133         /* Ignore empty lines.  */
 134         continue;
 135       src = cp;
 136
 137       do
 138         ++cp;
 139       while (*cp != '\0' && ! isspace (*cp));
 140       if (*cp != '\0')
 141         *cp++ = '\0';
 142
 143       while (isspace (*cp))
 144         ++cp;
 145       if (*cp == '\0')
 146         {
 147           fprintf (stderr, _("No target in line %d\n"), lineno);
 148           ret = 1;
 149           continue;
 150         }
 151       dest = cp;
 152
 153       do
 154         ++cp;
 155       while (*cp != '\0' && ! isspace (*cp));
 156       if (*cp != '\0')
 157         *cp++ = '\0';
 158
 159       ret |= makesymlink (src, dest);
 160     }
 161   fclose (fp);
 162
 163   return ret;
 164 }
 165
 166 static int
 167 makesymlink (src, dest)
 168      const char *src;
 169      const char *dest;
 170 {
 171   struct stat stats;
 172   const char *error;
 173
 174   /* Destination must not be a directory. */
 175   if (lstat (dest, &stats) == 0)
 176     {
 177       if (S_ISDIR (stats.st_mode))
 178         {
 179           fprintf (stderr, _("%s: destination must not be a directory\n"),
 180                    dest);
 181           return 1;
 182         }
 183       else if (unlink (dest) && errno != ENOENT)
 184         {
 185           fprintf (stderr, _("%s: failed to remove the old destination\n"),
 186                    dest);
 187           return 1;
 188         }
 189     }
 190   else if (errno != ENOENT)
 191     {
 192       error = strerror (errno);
 193       fprintf (stderr, _("%s: invalid destination: %s\n"), dest, error);
 194       return -1;
 195     }
 196
 197 #ifdef S_ISLNK
 198   if (symlink (src, dest) == 0)
 199 #else
 200   if (link (src, dest) == 0)
 201 #endif
 202     {
 203       /* Destination must exist by now. */
 204       if (access (dest, F_OK))
 205         {
 206           error = strerror (errno);
 207           unlink (dest);
 208           fprintf (stderr, _("Invalid link from \"%s\" to \"%s\": %s\n"),
 209                    src, dest, error);
 210           return 1;
 211         }
 212       return 0;
 213     }
 214   else
 215     {
 216       error = strerror (errno);
 217       fprintf (stderr, _("Invalid link from \"%s\" to \"%s\": %s\n"),
 218                src, dest, error);
 219       return 1;
 220     }
 221 }