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 int
  64 realpath_builtin(list)
  65 WORD_LIST       *list;
  66 {
  67         int     opt, cflag, vflag, sflag, es;
  68         char    *r, realbuf[PATH_MAX], *p;
  69         struct stat sb;
  70
  71         if (list == 0) {
  72                 builtin_usage();
  73                 return (EX_USAGE);
  74         }
  75
  76         vflag = cflag = sflag = 0;
  77         reset_internal_getopt();
  78         while ((opt = internal_getopt (list, "csv")) != -1) {
  79                 switch (opt) {
  80                 case 'c':
  81                         cflag = 1;
  82                         break;
  83                 case 's':
  84                         sflag = 1;
  85                         break;
  86                 case 'v':
  87                         vflag = 1;
  88                         break;
  89                 default:
  90                         builtin_usage();
  91                 }
  92         }
  93
  94         list = loptend;
  95
  96         if (list == 0)
  97                 builtin_usage();
  98
  99         for (es = EXECUTION_SUCCESS; list; list = list->next) {
 100                 p = list->word->word;
 101                 r = sh_realpath(p, realbuf);
 102                 if (r == 0) {
 103                         es = EXECUTION_FAILURE;
 104                         if (sflag == 0)
 105                                 builtin_error("%s: cannot resolve: %s", p, strerror(errno));
 106                         continue;
 107                 }
 108                 if (cflag && (stat(realbuf, &sb) < 0)) {
 109                         es = EXECUTION_FAILURE;
 110                         if (sflag == 0)
 111                                 builtin_error("%s: %s", p, strerror(errno));
 112                         continue;
 113                 }
 114                 if (sflag == 0) {
 115                         if (vflag)
 116                                 printf ("%s -> ", p);
 117                         printf("%s\n", realbuf);
 118                 }
 119         }
 120         return es;
 121 }
 122
 123 char *realpath_doc[] = {
 124         "Display pathname in canonical form.",
 125         "",
 126         "Display the canonicalized version of each PATHNAME argument, resolving",
 127         "symbolic links.  The -c option checks whether or not each resolved name",
 128         "exists.  The -s option produces no output; the exit status determines the",
 129         "valididty of each PATHNAME.  The -v option produces verbose output.  The",
 130         "exit status is 0 if each PATHNAME was resolved; non-zero otherwise.",
 131         (char *)NULL
 132 };
 133
 134 struct builtin realpath_struct = {
 135         "realpath",             /* builtin name */
 136         realpath_builtin,       /* function implementing the builtin */
 137         BUILTIN_ENABLED,        /* initial flags for builtin */
 138         realpath_doc,           /* array of long documentation strings */
 139         "realpath [-csv] pathname [pathname...]",       /* usage synopsis */
 140         0                       /* reserved for internal use */
 141 };