summaryrefslogtreecommitdiffstats
path: root/src/logname.c
blob: 1b0cc0da19282090bec6d1daf3da6a4022da9527 (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
/* logname -- print user's login name
   Copyright (C) 1990-2022 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/>.  */

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

#include "system.h"
#include "die.h"
#include "error.h"
#include "long-options.h"
#include "quote.h"

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

#define AUTHORS proper_name ("FIXME: unknown")

void
usage (int status)
{
  if (status != EXIT_SUCCESS)
    emit_try_help ();
  else
    {
      printf (_("Usage: %s [OPTION]\n"), program_name);
      fputs (_("\
Print the user's login name.\n\
\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      emit_ancillary_info (PROGRAM_NAME);
    }
  exit (status);
}

int
main (int argc, char **argv)
{
  char *cp;

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

  atexit (close_stdout);

  parse_gnu_standard_options_only (argc, argv, PROGRAM_NAME, PACKAGE_NAME,
                                   Version, true, usage, AUTHORS,
                                   (char const *) NULL);

  if (optind < argc)
    {
      error (0, 0, _("extra operand %s"), quote (argv[optind]));
      usage (EXIT_FAILURE);
    }

  /* POSIX requires using getlogin (or equivalent code) and prohibits
     using a fallback technique.  */
  cp = getlogin ();
  if (! cp)
    die (EXIT_FAILURE, 0, _("no login name"));

  puts (cp);
  return EXIT_SUCCESS;
}