openrc/src/rc/_usage.c

/*
 * Copyright 2007-2008 Roy Marples <roy@marples.name>
 * All rights reserved

 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if lint
#  define _noreturn
#endif
#if __GNUC__ > 2 || defined(__INTEL_COMPILER)
#  define _noreturn __attribute__ ((__noreturn__))
#else
#  define _noreturn
#endif

_noreturn static void
usage(int exit_status)
{
	const char * const has_arg[] = { "", "<arg>", "[arg]" };
	int i;
	int len;
	char *lo;
	char *p;
	char *token;

#ifdef usagestring
	printf(usagestring);
#else
	printf("Usage: %s [options] ", applet);
#endif
#ifdef extraopts
	printf(extraopts);
#endif
	printf("\n\nOptions: [" getoptstring "]\n");
	for (i = 0; longopts[i].name; ++i) {
		len = printf("  -%c, --%s %s", longopts[i].val, longopts[i].name,
		    has_arg[longopts[i].has_arg]);

		lo = p = xstrdup(longopts_help[i]);
		while ((token = strsep(&p, "\n"))) {
			while (++len < 37)
				printf(" ");
			puts(token);
			len = 0;
		}
		free(lo);
	}
	exit(exit_status);
}