summaryrefslogtreecommitdiff
path: root/src/readlink.c
blob: 9af6ae731f937f300fc09a5077a16adddda18890 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
/* readlink -- display value of a symbolic link.
   Copyright (C) 2002, 2003 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* Written by Dmitry V. Levin */

#include <config.h>
#include <stdio.h>
#include <getopt.h>
#include <sys/types.h>

#include "system.h"
#include "canonicalize.h"
#include "error.h"
#include "xreadlink.h"
#include "long-options.h"
#include "quote.h"

/* The official name of this program (e.g., no `g' prefix).  */
#define PROGRAM_NAME "readlink"

#define AUTHORS "Dmitry V. Levin"

/* Name this program was run with.  */
char *program_name;

  /* If nonzero, canonicalize file name. */
static int canonicalize;
  /* If nonzero, do not output the trailing newline. */
static int no_newline;
  /* If nonzero, report error messages. */
static int verbose;

static struct option const longopts[] =
{
  {"canonicalize", no_argument, 0, 'f'},
  {"no-newline", no_argument, 0, 'n'},
  {"quiet", no_argument, 0, 'q'},
  {"silent", no_argument, 0, 's'},
  {"verbose", no_argument, 0, 'v'},
  {GETOPT_HELP_OPTION_DECL},
  {GETOPT_VERSION_OPTION_DECL},
  {NULL, 0, NULL, 0}
};

void
usage (int status)
{
  if (status != EXIT_SUCCESS)
    fprintf (stderr, _("Try `%s --help' for more information.\n"),
	     program_name);
  else
    {
      printf (_("Usage: %s [OPTION]... FILE\n"), program_name);
      fputs (_("Display value of a symbolic link on standard output.\n\n"),
	     stdout);
      fputs (_("\
  -f, --canonicalize      canonicalize by following every symlink in every\n\
                          component of the given path recursively\n\
  -n, --no-newline        do not output the trailing newline\n\
  -q, --quiet,\n\
  -s, --silent            suppress most error messages\n\
  -v, --verbose           report error messages\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
    }
  exit (status);
}

int
main (int argc, char *const argv[])
{
  const char *fname;
  char *value;
  int optc;

  initialize_main (&argc, &argv);
  program_name = argv[0];
  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  atexit (close_stdout);

  while ((optc = getopt_long (argc, argv, "fnqsv", longopts, NULL)) != -1)
    {
      switch (optc)
	{
	case 0:
	  break;
	case 'f':
	  canonicalize = 1;
	  break;
	case 'n':
	  no_newline = 1;
	  break;
	case 'q':
	case 's':
	  verbose = 0;
	  break;
	case 'v':
	  verbose = 1;
	  break;
	case_GETOPT_HELP_CHAR;
	case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
	default:
	  usage (EXIT_FAILURE);
	}
    }

  if (optind >= argc)
    {
      error (0, 0, _("too few arguments"));
      usage (EXIT_FAILURE);
    }

  fname = argv[optind++];

  if (optind < argc)
    {
      error (0, 0, _("too many arguments"));
      usage (EXIT_FAILURE);
    }

  value = (canonicalize ? canonicalize_file_name : xreadlink) (fname);
  if (value)
    {
      printf ("%s%s", value, (no_newline ? "" : "\n"));
      free (value);
      return EXIT_SUCCESS;
    }

  if (verbose)
    error (EXIT_FAILURE, errno, "%s", fname);

  return EXIT_FAILURE;
}