examples/loadables/realpath.c

   1 /*
   2  * realpath -- canonicalize pathnames, resolving symlinks
   3  *
   4  * usage: realpath [-csv] pathname [pathname...]
   5  *
   6  * options:     -c      check whether or not each resolved path exists
   7  *              -s      no output, exit status determines whether path is valid
   8  *              -v      produce verbose output
   9  *
  10  *
  11  * exit status: 0       if all pathnames resolved
  12  *              1       if any of the pathname arguments could not be resolved
  13  *
  14  *
  15  * Bash loadable builtin version
  16  *
  17  * Chet Ramey
  18  * chet@po.cwru.edu
  19  */
  20
  21 /*
  22    Copyright (C) 1999-2009 Free Software Foundation, Inc.
  23
  24    This file is part of GNU Bash.
  25    Bash is free software: you can redistribute it and/or modify
  26    it under the terms of the GNU General Public License as published by
  27    the Free Software Foundation, either version 3 of the License, or
  28    (at your option) any later version.
  29
  30    Bash is distributed in the hope that it will be useful,
  31    but WITHOUT ANY WARRANTY; without even the implied warranty of
  32    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  33    GNU General Public License for more details.
  34
  35    You should have received a copy of the GNU General Public License
  36    along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  37 */
  38
  39 #include "config.h"
  40
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43
  44 #include <stdio.h>
  45 #ifdef HAVE_UNISTD_H
  46 #  include <unistd.h>
  47 #endif
  48 #include "bashansi.h"
  49 #include <maxpath.h>
  50 #include <errno.h>
  51
  52 #include "builtins.h"
  53 #include "shell.h"
  54 #include "bashgetopt.h"
  55 #include "common.h"
  56
  57 #ifndef errno
  58 extern int      errno;
  59 #endif
  60
  61 extern char     *sh_realpath();
  62
  63 realpath_builtin(list)
  64 WORD_LIST       *list;
  65 {
  66         int     opt, cflag, vflag, sflag, es;
  67         char    *r, realbuf[PATH_MAX], *p;
  68         struct stat sb;
  69
  70         if (list == 0) {
  71                 builtin_usage();
  72                 return (EX_USAGE);
  73         }
  74
  75         vflag = cflag = sflag = 0;
  76         reset_internal_getopt();
  77         while ((opt = internal_getopt (list, "csv")) != -1) {
  78                 switch (opt) {
  79                 case 'c':
  80                         cflag = 1;
  81                         break;
  82                 case 's':
  83                         sflag = 1;
  84                         break;
  85                 case 'v':
  86                         vflag = 1;
  87                         break;
  88                 default:
  89                         builtin_usage();
  90                 }
  91         }
  92
  93         list = loptend;
  94
  95         if (list == 0)
  96                 builtin_usage();
  97
  98         for (es = EXECUTION_SUCCESS; list; list = list->next) {
  99                 p = list->word->word;
 100                 r = sh_realpath(p, realbuf);
 101                 if (r == 0) {
 102                         es = EXECUTION_FAILURE;
 103                         if (sflag == 0)
 104                                 builtin_error("%s: cannot resolve: %s", p, strerror(errno));
 105                         continue;
 106                 }
 107                 if (cflag && (stat(realbuf, &sb) < 0)) {
 108                         es = EXECUTION_FAILURE;
 109                         if (sflag == 0)
 110                                 builtin_error("%s: %s", p, strerror(errno));
 111                         continue;
 112                 }
 113                 if (sflag == 0) {
 114                         if (vflag)
 115                                 printf ("%s -> ", p);
 116                         printf("%s\n", realbuf);
 117                 }
 118         }
 119         return es;
 120 }
 121
 122 char *realpath_doc[] = {
 123         "Display pathname in canonical form.",
 124         "",
 125         "Display the canonicalized version of each PATHNAME argument, resolving",
 126         "symbolic links.  The -c option checks whether or not each resolved name",
 127         "exists.  The -s option produces no output; the exit status determines the",
 128         "valididty of each PATHNAME.  The -v option produces verbose output.  The",
 129         "exit status is 0 if each PATHNAME was resolved; non-zero otherwise.",
 130         (char *)NULL
 131 };
 132
 133 struct builtin realpath_struct = {
 134         "realpath",             /* builtin name */
 135         realpath_builtin,       /* function implementing the builtin */
 136         BUILTIN_ENABLED,        /* initial flags for builtin */
 137         realpath_doc,           /* array of long documentation strings */
 138         "realpath [-csv] pathname [pathname...]",       /* usage synopsis */
 139         0                       /* reserved for internal use */
 140 };