/* readlink -- display value of a symbolic link. This is the readlink utility
Copyright (C) 2002-2018 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 3 of the License, 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, see <https://www.gnu.org/licenses/>. */ The GNUv3 license
/* Written by Dmitry V. Levin */
#include <config.h> Provides system specific information
#include <stdio.h> Provides standard I/O capability
#include <getopt.h> ...!includes auto-comment...
#include <sys/types.h> Provides system data types
#include "system.h" ...!includes auto-comment...
#include "canonicalize.h" ...!includes auto-comment...
#include "error.h" ...!includes auto-comment...
#include "areadlink.h" ...!includes auto-comment...
/* The official name of this program (e.g., no 'g' prefix). */
#define PROGRAM_NAME "readlink" Line 30
#define AUTHORS proper_name ("Dmitry V. Levin") Line 32
/* If true, do not output the trailing newline. */
static bool no_newline; Line 35
/* If true, report error messages. */
static bool verbose; Line 38
static struct option const longopts[] = Line 40
{
{"canonicalize", no_argument, NULL, 'f'}, Line 42
{"canonicalize-existing", no_argument, NULL, 'e'}, Line 43
{"canonicalize-missing", no_argument, NULL, 'm'}, Line 44
{"no-newline", no_argument, NULL, 'n'}, Line 45
{"quiet", no_argument, NULL, 'q'}, Line 46
{"silent", no_argument, NULL, 's'}, Line 47
{"verbose", no_argument, NULL, 'v'}, Line 48
{"zero", no_argument, NULL, 'z'}, Line 49
{GETOPT_HELP_OPTION_DECL}, Line 50
{GETOPT_VERSION_OPTION_DECL}, Line 51
{NULL, 0, NULL, 0} Line 52
}; Block 1
void Line 55
usage (int status) Line 56
{
if (status != EXIT_SUCCESS) Line 58
emit_try_help (); ...!common auto-comment...
else Line 60
{
printf (_("Usage: %s [OPTION]... FILE...\n"), program_name); Line 62
fputs (_("Print value of a symbolic link or canonical file name\n\n"), Line 63
stdout); Line 64
fputs (_("\ Line 65
-f, --canonicalize canonicalize by following every symlink in\n\ Line 66
every component of the given name recursively;\ Line 67
\n\
all but the last component must exist\n\ Line 69
-e, --canonicalize-existing canonicalize by following every symlink in\n\ Line 70
every component of the given name recursively,\ Line 71
\n\
all components must exist\n\ Line 73
"), stdout); Line 74
fputs (_("\ Line 75
-m, --canonicalize-missing canonicalize by following every symlink in\n\ Line 76
every component of the given name recursively,\ Line 77
\n\
without requirements on components existence\n\ Line 79
-n, --no-newline do not output the trailing delimiter\n\ Line 80
-q, --quiet\n\ Line 81
-s, --silent suppress most error messages (on by default)\n\ Line 82
-v, --verbose report error messages\n\ Line 83
-z, --zero end each output line with NUL, not newline\n\ Line 84
"), stdout); Line 85
fputs (HELP_OPTION_DESCRIPTION, stdout); Line 86
fputs (VERSION_OPTION_DESCRIPTION, stdout); Line 87
emit_ancillary_info (PROGRAM_NAME); Line 88
}
exit (status); Line 90
} Block 2
int
main (int argc, char **argv) Line 94
{
/* If not -1, use this method to canonicalize. */
int can_mode = -1; Line 97
int status = EXIT_SUCCESS; Line 98
int optc; Line 99
bool use_nuls = false; Line 100
initialize_main (&argc, &argv); VMS-specific entry point handling wildcard expansion
set_program_name (argv[0]); Retains program name and discards path
setlocale (LC_ALL, ""); Sets up internationalization (i18n)
bindtextdomain (PACKAGE, LOCALEDIR); Assigns i18n directorySets text domain for _() [gettext()] function
textdomain (PACKAGE); Sets text domain for _() [gettext()] function
atexit (close_stdout); Close stdout on exit (see gnulib)
while ((optc = getopt_long (argc, argv, "efmnqsvz", longopts, NULL)) != -1) Line 110
{
switch (optc) Line 112
{
case 'e': Line 114
can_mode = CAN_EXISTING; Line 115
break; Line 116
case 'f': Line 117
can_mode = CAN_ALL_BUT_LAST; Line 118
break; Line 119
case 'm': Line 120
can_mode = CAN_MISSING; Line 121
break; Line 122
case 'n': Line 123
no_newline = true; Line 124
break; Line 125
case 'q': Line 126
case 's': Line 127
verbose = false; Line 128
break; Line 129
case 'v': Line 130
verbose = true; Line 131
break; Line 132
case 'z': Line 133
use_nuls = true; Line 134
break; Line 135
case_GETOPT_HELP_CHAR; Line 136
case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS); Line 137
default: Line 138
usage (EXIT_FAILURE); Line 139
}
}
if (optind >= argc) Line 143
{
error (0, 0, _("missing operand")); Line 145
usage (EXIT_FAILURE); Line 146
}
if (argc - optind > 1) Line 149
{
if (no_newline) Line 151
error (0, 0, _("ignoring --no-newline with multiple arguments")); Line 152
no_newline = false; Line 153
}
for (; optind < argc; ++optind) Line 156
{
const char *fname = argv[optind]; Line 158
char *value = (can_mode != -1 Line 159
? canonicalize_filename_mode (fname, can_mode) Line 160
: areadlink_with_size (fname, 63)); Line 161
if (value) Line 162
{
fputs (value, stdout); Line 164
if (! no_newline) Line 165
putchar (use_nuls ? '\0' : '\n'); Line 166
free (value); Line 167
}
else Line 169
{
status = EXIT_FAILURE; Line 171
if (verbose) Line 172
error (0, errno, "%s", quotef (fname)); Line 173
}
}
return status; Line 177
}