busybox/coreutils/ln.c

/* vi: set sw=4 ts=4: */
/*
 * Mini ln implementation for busybox
 *
 * Copyright (C) 1999-2003 by Erik Andersen <andersen@codepoet.org>
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

/* BB_AUDIT SUSv3 compliant */
/* BB_AUDIT GNU options missing: -b, -d, -F, -i, -S, and -v. */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/ln.html */

/* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
 *
 * Fixed bug involving -n option.  Essentially, -n was always in effect.
 */

#include <stdlib.h>
#include <unistd.h>
#include "busybox.h"

#define LN_SYMLINK          1
#define LN_FORCE            2
#define LN_NODEREFERENCE    4

extern int ln_main(int argc, char **argv)
{
	int status = EXIT_SUCCESS;
	int flag;
	char *last;
	char *src_name;
	const char *src;
	int (*link_func)(const char *, const char *);

	flag = bb_getopt_ulflags(argc, argv, "sfn");

	if (argc == optind) {
		bb_show_usage();
	}

	last = argv[argc - 1];
	argv += optind;

	if (argc == optind + 1) {
		*--argv = last;
		last = bb_get_last_path_component(bb_xstrdup(last));
	}

	do {
		src_name = 0;
		src = last;

		if (is_directory(src,
						 (flag & LN_NODEREFERENCE) ^ LN_NODEREFERENCE,
						 NULL)) {
			src_name = bb_xstrdup(*argv);
			src = concat_path_file(src, bb_get_last_path_component(src_name));
			free(src_name);
			src_name = (char *)src;
		}

		if (flag & LN_FORCE) {
			unlink(src);
		}

		link_func = link;
		if (flag & LN_SYMLINK) {
			link_func = symlink;
		}
		
		if (link_func(*argv, src) != 0) {
			bb_perror_msg(src);
			status = EXIT_FAILURE;;
		}

		free(src_name);
		
	} while ((++argv)[1]);

	return status;
}