/*
* Mini ln implementation for busybox
*
- * Copyright (C) 1999,2000 by Lineo, inc. and Erik Andersen
- * Copyright (C) 1999,2000,2001 by Erik Andersen <andersee@debian.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
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
+//config:config LN
+//config: bool "ln (4.9 kb)"
+//config: default y
+//config: help
+//config: ln is used to create hard or soft links between files.
-#include <stdio.h>
-#include <dirent.h>
-#include <string.h>
-#include <stdlib.h>
-#include <errno.h>
-#include <unistd.h>
-#include "busybox.h"
+//applet:IF_LN(APPLET_NOEXEC(ln, ln, BB_DIR_BIN, BB_SUID_DROP, ln))
+//kbuild:lib-$(CONFIG_LN) += ln.o
-static const int LN_SYMLINK = 1;
-static const int LN_FORCE = 2;
-static const int LN_NODEREFERENCE = 4;
+/* BB_AUDIT SUSv3 compliant */
+/* BB_AUDIT GNU options missing: -d, -F, -i, and -v. */
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/ln.html */
-/*
- * linkDestName is where the link points to,
- * linkSrcName is the name of the link to be created.
- */
-static int fs_link(const char *link_destname, const char *link_srcname,
- const int flag)
-{
- int status;
- int src_is_dir;
- char *src_name = 0;
- const char *src;
-
- if (link_destname==NULL)
- return(FALSE);
-
- if (link_srcname==NULL)
- src = link_destname;
- else
- src = link_srcname;
-
- if (flag&LN_NODEREFERENCE)
- src_is_dir = is_directory(src, TRUE, NULL);
- else
- src_is_dir = is_directory(src, FALSE, NULL);
-
- if ((src_is_dir==TRUE)&&((flag&LN_NODEREFERENCE)==0)) {
- char* srcdir_name;
-
- srcdir_name = xstrdup(link_destname);
- src_name = concat_path_file(src, get_last_path_component(srcdir_name));
- src = src_name;
- free(srcdir_name);
- }
-
- if (flag&LN_FORCE)
- unlink(src);
-
- if (flag&LN_SYMLINK)
- status = symlink(link_destname, src);
- else
- status = link(link_destname, src);
-
- if (status != 0) {
- perror_msg(src);
- status = FALSE;
- } else {
- status = TRUE;
- }
- free(src_name);
- return status;
-}
+//usage:#define ln_trivial_usage
+//usage: "[OPTIONS] TARGET... LINK|DIR"
+//usage:#define ln_full_usage "\n\n"
+//usage: "Create a link LINK or DIR/TARGET to the specified TARGET(s)\n"
+//usage: "\n -s Make symlinks instead of hardlinks"
+//usage: "\n -f Remove existing destinations"
+//usage: "\n -n Don't dereference symlinks - treat like normal file"
+//usage: "\n -b Make a backup of the target (if exists) before link operation"
+//usage: "\n -S suf Use suffix instead of ~ when making backup files"
+//usage: "\n -T 2nd arg must be a DIR"
+//usage: "\n -v Verbose"
+//usage:
+//usage:#define ln_example_usage
+//usage: "$ ln -s BusyBox /tmp/ls\n"
+//usage: "$ ls -l /tmp/ls\n"
+//usage: "lrwxrwxrwx 1 root root 7 Apr 12 18:39 ls -> BusyBox*\n"
-extern int ln_main(int argc, char **argv)
+#include "libbb.h"
+
+/* This is a NOEXEC applet. Be very careful! */
+
+
+#define LN_SYMLINK (1 << 0)
+#define LN_FORCE (1 << 1)
+#define LN_NODEREFERENCE (1 << 2)
+#define LN_BACKUP (1 << 3)
+#define LN_SUFFIX (1 << 4)
+#define LN_VERBOSE (1 << 5)
+#define LN_LINKFILE (1 << 6)
+
+int ln_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int ln_main(int argc, char **argv)
{
int status = EXIT_SUCCESS;
- int flag = 0;
- int opt;
-
- /* Parse any options */
- while ((opt=getopt(argc, argv, "sfn")) != -1) {
- switch(opt) {
- case 's':
- flag |= LN_SYMLINK;
- break;
- case 'f':
- flag |= LN_FORCE;
- break;
- case 'n':
- flag |= LN_NODEREFERENCE;
- break;
- default:
- show_usage();
- }
+ int opts;
+ char *last;
+ char *src_name;
+ char *src;
+ char *suffix = (char*)"~";
+ struct stat statbuf;
+ int (*link_func)(const char *, const char *);
+
+ opts = getopt32(argv, "^" "sfnbS:vT" "\0" "-1", &suffix);
+
+ last = argv[argc - 1];
+ argv += optind;
+ argc -= optind;
+
+ if ((opts & LN_LINKFILE) && argc > 2) {
+ bb_error_msg_and_die("-T accepts 2 args max");
}
- if (optind > (argc-1)) {
- show_usage();
- }
- if (optind == (argc-1)) {
- if (fs_link(argv[optind],
- get_last_path_component(argv[optind]), flag)==FALSE)
- status = EXIT_FAILURE;
+
+ if (!argv[1]) {
+ /* "ln PATH/TO/FILE" -> "ln PATH/TO/FILE FILE" */
+ *--argv = last;
+ /* xstrdup is needed: "ln -s PATH/TO/FILE/" is equivalent to
+ * "ln -s PATH/TO/FILE/ FILE", not "ln -s PATH/TO/FILE FILE"
+ */
+ last = bb_get_last_path_component_strip(xstrdup(last));
}
- while(optind<(argc-1)) {
- if (fs_link(argv[optind], argv[argc-1], flag)==FALSE)
+
+ do {
+ src_name = NULL;
+ src = last;
+
+ if (is_directory(src,
+ (opts & LN_NODEREFERENCE) ^ LN_NODEREFERENCE
+ )
+ ) {
+ if (opts & LN_LINKFILE) {
+ bb_error_msg_and_die("'%s' is a directory", src);
+ }
+ src_name = xstrdup(*argv);
+ src = concat_path_file(src, bb_get_last_path_component_strip(src_name));
+ free(src_name);
+ src_name = src;
+ }
+ if (!(opts & LN_SYMLINK) && stat(*argv, &statbuf)) {
+ // coreutils: "ln dangling_symlink new_hardlink" works
+ if (lstat(*argv, &statbuf) || !S_ISLNK(statbuf.st_mode)) {
+ bb_simple_perror_msg(*argv);
+ status = EXIT_FAILURE;
+ free(src_name);
+ continue;
+ }
+ }
+
+ if (opts & LN_BACKUP) {
+ char *backup;
+ backup = xasprintf("%s%s", src, suffix);
+ if (rename(src, backup) < 0 && errno != ENOENT) {
+ bb_simple_perror_msg(src);
+ status = EXIT_FAILURE;
+ free(backup);
+ continue;
+ }
+ free(backup);
+ /*
+ * When the source and dest are both hard links to the same
+ * inode, a rename may succeed even though nothing happened.
+ * Therefore, always unlink().
+ */
+ unlink(src);
+ } else if (opts & LN_FORCE) {
+ unlink(src);
+ }
+
+ link_func = link;
+ if (opts & LN_SYMLINK) {
+ link_func = symlink;
+ }
+
+ if (opts & LN_VERBOSE) {
+ printf("'%s' -> '%s'\n", src, *argv);
+ }
+
+ if (link_func(*argv, src) != 0) {
+ bb_simple_perror_msg(src);
status = EXIT_FAILURE;
- optind++;
- }
+ }
+
+ free(src_name);
+ } while ((++argv)[1]);
+
return status;
}
-
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/
projects / oweals / busybox.git / blobdiff