docs: add a new command boilerplate code

Having howtos is good, having an working code that can be used as-is to
kickstart a write of a new command is better.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/Documentation/boilerplate.c b/Documentation/boilerplate.c
new file mode 100644 (file)
index 0000000..3ee7d7b
--- /dev/null
+++ b/Documentation/boilerplate.c
@@ -0,0 +1,100 @@
+/* Please use this file as a template when introducing new command to
+ * util-linux package.
+ * -- remove above */
+/*
+ * fixme-command-name - purpose of it
+ *
+ * Copyright (c) 20nn  Example Commercial, Inc
+ * Written by Your Name <you@example.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it would 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <getopt.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "c.h"
+#include "closestream.h"
+#include "nls.h"
+
+static void __attribute__((__noreturn__)) usage(FILE *out)
+{
+       fputs(USAGE_HEADER, out);
+       fprintf(out, _(" %s [options] file...\n"), program_invocation_short_name);
+       fputs(USAGE_OPTIONS, out);
+       fputs(_(" -n, --no-argument       option does not use argument\n"), out);
+       fputs(_(" -o, --optional[=<arg>]  option argument is optional\n"), out);
+       fputs(_(" -r, --required <arg>    option requires an argument\n"), out);
+       fputs(_(" -z                      no long option\n"), out);
+       fputs(_("     --xyzzy             a long option only\n"), out);
+       fputs(_(" -e, --extremely-long-long-option\n"), out);
+       fputs(_("                         use next line for description when needed\n"), out);
+       fputs(_(" -l, --long-explanation  an example of very verbose, and chatty option\n"), out);
+       fputs(_("                           description on two, or multiple lines, where the\n"), out);
+       fputs(_("                           consecutive lines are intended by two spaces\n"), out);
+       fputs(_(" -f, --foobar            next option description resets indent\n"), out);
+       fputs(USAGE_SEPARATOR, out);
+       fputs(USAGE_HELP, out);
+       fputs(USAGE_VERSION, out);
+       fprintf(out, USAGE_MAN_TAIL("fixme-command-name(1)"));
+       exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
+}
+
+int main(int argc, char **argv)
+{
+       int c;
+
+       enum {
+               OPT_XYZZY = CHAR_MAX + 1
+       };
+       static const struct option longopts[] = {
+               {"no-argument", no_argument, NULL, 'n'},
+               {"optional", optional_argument, NULL, 'o'},
+               {"required", required_argument, NULL, 'r'},
+               {"xyzzy", no_argument, NULL, OPT_XYZZY},
+               {"extremely-long-long-option", no_argument, NULL, 'e'},
+               {"long-explanation", no_argument, NULL, 'l'},
+               {"foobar", no_argument, NULL, 'f'},
+               {"version", no_argument, NULL, 'V'},
+               {"help", no_argument, NULL, 'h'},
+               {NULL, 0, NULL, 0}
+       };
+
+       setlocale(LC_ALL, "");
+       bindtextdomain(PACKAGE, LOCALEDIR);
+       textdomain(PACKAGE);
+       atexit(close_stdout);
+
+       while ((c = getopt_long(argc, argv, "no::r:elfVh", longopts, NULL)) != -1)
+               switch (c) {
+               case 'n':
+               case 'o':
+               case 'r':
+               case OPT_XYZZY:
+               case 'e':
+               case 'l':
+               case 'f':
+                       break;
+               case 'V':
+                       printf(UTIL_LINUX_VERSION);
+                       return EXIT_SUCCESS;
+               case 'h':
+                       usage(stdout);
+               default:
+                       usage(stderr);
+               }
+
+       return EXIT_SUCCESS;
+}