elf/sln.c

   1 /* `sln' program to create symbolic links between files.
   2    Copyright (C) 1998-2016 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 %s%s\n", PKGVERSION, 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   printf (_("For bug reporting instructions, please see:\n\
  86 %s.\n"), REPORT_BUGS_TO);
  87 }
  88
  89 static int
  90 makesymlinks (const char *file)
  91 {
  92 #ifndef PATH_MAX
  93 #define PATH_MAX 4095
  94 #endif
  95   char *buffer = NULL;
  96   size_t bufferlen = 0;
  97   int ret;
  98   int lineno;
  99   FILE *fp;
 100
 101   if (strcmp (file, "-") == 0)
 102     fp = stdin;
 103   else
 104     {
 105       fp = fopen (file, "r");
 106       if (fp == NULL)
 107         {
 108           fprintf (stderr, _("%s: file open error: %m\n"), file);
 109           return 1;
 110         }
 111     }
 112
 113   ret = 0;
 114   lineno = 0;
 115   while (!feof_unlocked (fp))
 116     {
 117       ssize_t n = getline (&buffer, &bufferlen, fp);
 118       char *src;
 119       char *dest;
 120       char *cp = buffer;
 121
 122       if (n < 0)
 123         break;
 124       if (buffer[n - 1] == '\n')
 125         buffer[n - 1] = '\0';
 126
 127       ++lineno;
 128       while (isspace (*cp))
 129         ++cp;
 130       if (*cp == '\0')
 131         /* Ignore empty lines.  */
 132         continue;
 133       src = cp;
 134
 135       do
 136         ++cp;
 137       while (*cp != '\0' && ! isspace (*cp));
 138       if (*cp != '\0')
 139         *cp++ = '\0';
 140
 141       while (isspace (*cp))
 142         ++cp;
 143       if (*cp == '\0')
 144         {
 145           fprintf (stderr, _("No target in line %d\n"), lineno);
 146           ret = 1;
 147           continue;
 148         }
 149       dest = cp;
 150
 151       do
 152         ++cp;
 153       while (*cp != '\0' && ! isspace (*cp));
 154       if (*cp != '\0')
 155         *cp++ = '\0';
 156
 157       ret |= makesymlink (src, dest);
 158     }
 159   fclose (fp);
 160
 161   return ret;
 162 }
 163
 164 static int
 165 makesymlink (const char *src, const char *dest)
 166 {
 167   struct stat64 stats;
 168   const char *error;
 169
 170   /* Destination must not be a directory. */
 171   if (lstat64 (dest, &stats) == 0)
 172     {
 173       if (S_ISDIR (stats.st_mode))
 174         {
 175           fprintf (stderr, _("%s: destination must not be a directory\n"),
 176                    dest);
 177           return 1;
 178         }
 179       else if (unlink (dest) && errno != ENOENT)
 180         {
 181           fprintf (stderr, _("%s: failed to remove the old destination\n"),
 182                    dest);
 183           return 1;
 184         }
 185     }
 186   else if (errno != ENOENT)
 187     {
 188       error = strerror (errno);
 189       fprintf (stderr, _("%s: invalid destination: %s\n"), dest, error);
 190       return -1;
 191     }
 192
 193 #ifdef S_ISLNK
 194   if (symlink (src, dest) == 0)
 195 #else
 196   if (link (src, dest) == 0)
 197 #endif
 198     {
 199       /* Destination must exist by now. */
 200       if (access (dest, F_OK))
 201         {
 202           error = strerror (errno);
 203           unlink (dest);
 204           fprintf (stderr, _("Invalid link from \"%s\" to \"%s\": %s\n"),
 205                    src, dest, error);
 206           return 1;
 207         }
 208       return 0;
 209     }
 210   else
 211     {
 212       error = strerror (errno);
 213       fprintf (stderr, _("Invalid link from \"%s\" to \"%s\": %s\n"),
 214                src, dest, error);
 215       return 1;
 216     }
 217 }