Documentation/boilerplate.c

   1 /* Please use this file as a template when introducing new command to
   2  * util-linux package.
   3  * -- remove above */
   4 /*
   5  * SPDX-License-Identifier: GPL-2.0-or-later
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * Copyright (c) 20nn  Example Commercial, Inc
  13  * Written by Your Name <you@example.com>
  14  *
  15  * fixme-command-name - purpose of it
  16  */
  17 #include <getopt.h>
  18 #include <stdio.h>
  19 #include <unistd.h>
  20
  21 #include "c.h"
  22 #include "closestream.h"
  23 #include "nls.h"
  24
  25 /*
  26  * FIXME: remove this comment.
  27  * Other usage() constants that are not demonstrated below:
  28  * USAGE_FUNCTIONS USAGE_COMMANDS USAGE_COLUMNS
  29  */
  30 static void __attribute__((__noreturn__)) usage(void)
  31 {
  32         fputs(USAGE_HEADER, stdout);
  33         fprintf(stdout, _(" %s [options] file...\n"), program_invocation_short_name);
  34
  35         fputs(USAGE_SEPARATOR, stdout);
  36         fputs(_("Short program description."), stdout);
  37
  38         fputs(USAGE_OPTIONS, stdout);
  39         fputs(_(" -n, --no-argument       option does not use argument"), stdout);
  40         fputs(_("     --optional[=<arg>]  option argument is optional"), stdout);
  41         fputs(_(" -r, --required <arg>    option requires an argument"), stdout);
  42         fputs(_(" -z                      no long option"), stdout);
  43         fputs(_("     --xyzzy             a long option only"), stdout);
  44         fputs(_(" -e, --extremely-long-long-option\n"
  45                 "                         use next line for description when needed"), stdout);
  46         fputs(_(" -l, --long-explanation  an example of very verbose, and chatty option\n"
  47                 "                           description on two, or multiple lines, where the\n"
  48                 "                           consecutive lines are intended by two spaces"), stdout);
  49         fputs(_(" -f, --foobar            next option description resets indent"), stdout);
  50         fputs(USAGE_SEPARATOR, stdout);
  51         fprintf(stdout, USAGE_HELP_OPTIONS(25)); /* char offset to align option descriptions */
  52         fprintf(stdout, USAGE_MAN_TAIL("fixme-command-name(1)"));
  53         exit(EXIT_SUCCESS);
  54 }
  55
  56 int main(int argc, char **argv)
  57 {
  58         int c;
  59
  60         enum {
  61                 OPT_XYZZY = CHAR_MAX + 1,
  62                 OPT_OPTIONAL    /* see howto-man-page.txt about short option */
  63         };
  64         static const struct option longopts[] = {
  65                 { "no-argument",                no_argument,       NULL, 'n'          },
  66                 { "optional",                   optional_argument, NULL, OPT_OPTIONAL },
  67                 { "required",                   required_argument, NULL, 'r'          },
  68                 { "extremely-long-long-option", no_argument,       NULL, 'e'          },
  69                 { "xyzzy",                      no_argument,       NULL, OPT_XYZZY    },
  70                 { "long-explanation",           no_argument,       NULL, 'l'          },
  71                 { "foobar",                     no_argument,       NULL, 'f'          },
  72                 { "version",                    no_argument,       NULL, 'V'          },
  73                 { "help",                       no_argument,       NULL, 'h'          },
  74                 { NULL, 0, NULL, 0 }
  75         };
  76
  77         setlocale(LC_ALL, "");
  78         bindtextdomain(PACKAGE, LOCALEDIR);
  79         textdomain(PACKAGE);
  80         close_stdout_atexit();
  81
  82         while ((c = getopt_long(argc, argv, "nr:zelfVh", longopts, NULL)) != -1)
  83                 switch (c) {
  84                 case 'n':
  85                 case OPT_OPTIONAL:
  86                 case 'r':
  87                 case 'z':
  88                 case OPT_XYZZY:
  89                 case 'e':
  90                 case 'l':
  91                 case 'f':
  92                         break;
  93                 case 'V':
  94                         print_version(EXIT_SUCCESS);
  95                 case 'h':
  96                         usage();
  97                 default:
  98                         errtryhelp(EXIT_FAILURE);
  99                 }
 100
 101         return EXIT_SUCCESS;
 102 }