/*
* Mini ln implementation for busybox
*
- * Copyright (C) 1999,2000 by Lineo, inc.
- * Written by Erik Andersen <andersen@lineo.com>, <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.
*/
-
-#include "internal.h"
-#define BB_DECLARE_EXTERN
-#define bb_need_name_too_long
-#define bb_need_not_a_directory
-#include "messages.c"
-
-#include <stdio.h>
-#include <dirent.h>
-#include <errno.h>
-
-static const char ln_usage[] =
- "ln [OPTION] TARGET... LINK_NAME|DIRECTORY\n"
-#ifndef BB_FEATURE_TRIVIAL_HELP
- "\nCreate a link named LINK_NAME or DIRECTORY to the specified TARGET\n\n"
- "Options:\n"
- "\t-s\tmake symbolic links instead of hard links\n"
-
- "\t-f\tremove existing destination files\n"
- "\t-n\tno dereference symlinks - treat like normal file\n"
-#endif
- ;
-
-static int symlinkFlag = FALSE;
-static int removeoldFlag = FALSE;
-static int followLinks = TRUE;
-
-extern int ln_main(int argc, char **argv)
+//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.
+
+//applet:IF_LN(APPLET_NOEXEC(ln, ln, BB_DIR_BIN, BB_SUID_DROP, ln))
+
+//kbuild:lib-$(CONFIG_LN) += ln.o
+
+/* BB_AUDIT SUSv3 compliant */
+/* BB_AUDIT GNU options missing: -d, -F, -i, and -v. */
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/ln.html */
+
+//usage:#define ln_trivial_usage
+//usage: "[OPTIONS] TARGET... LINK|DIR"
+//usage:#define ln_full_usage "\n\n"
+//usage: "Create a link LINK or DIR/TARGET to the specified TARGET(s)\n"
+//usage: "\n -s Make symlinks instead of hardlinks"
+//usage: "\n -f Remove existing destinations"
+//usage: "\n -n Don't dereference symlinks - treat like normal file"
+//usage: "\n -b Make a backup of the target (if exists) before link operation"
+//usage: "\n -S suf Use suffix instead of ~ when making backup files"
+//usage: "\n -T 2nd arg must be a DIR"
+//usage: "\n -v Verbose"
+//usage:
+//usage:#define ln_example_usage
+//usage: "$ 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"
+
+#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)
{
- char *linkName;
- int linkIntoDirFlag;
-
- if (argc < 3) {
- usage(ln_usage);
- }
- argc--;
- argv++;
-
- /* Parse any options */
- while (--argc >= 0 && *argv && **argv) {
- while (**argv == '-') {
- while (*++(*argv))
- switch (**argv) {
- case 's':
- symlinkFlag = TRUE;
- break;
- case 'f':
- removeoldFlag = TRUE;
- break;
- case 'n':
- followLinks = FALSE;
- break;
- default:
- usage(ln_usage);
- }
- }
- argv++;
- }
-
- if (argc < 1) {
- fatalError("ln: missing file argument\n");
+ int status = EXIT_SUCCESS;
+ 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");
}
- linkName = argv[argc - 1];
-
- if (strlen(linkName) > BUFSIZ) {
- fprintf(stderr, name_too_long, "ln");
- exit FALSE;
+ 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));
}
- linkIntoDirFlag = isDirectory(linkName, TRUE, NULL);
-
- if ((argc > 3) && !linkIntoDirFlag) {
- fprintf(stderr, not_a_directory, "ln", linkName);
- exit FALSE;
- }
+ do {
+ src_name = NULL;
+ src = last;
- while (argc-- >= 2) {
- char srcName[BUFSIZ + 1];
- int nChars, status;
+ 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 (strlen(*argv) > BUFSIZ) {
- fprintf(stderr, name_too_long, "ln");
- exit FALSE;
+ 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);
}
- if (followLinks == FALSE) {
- strcpy(srcName, *argv);
- } else {
- /* Warning! This can silently truncate if > BUFSIZ, but
- I don't think that there can be one > BUFSIZ anyway. */
- nChars = readlink(*argv, srcName, BUFSIZ);
- srcName[nChars] = '\0';
+ link_func = link;
+ if (opts & LN_SYMLINK) {
+ link_func = symlink;
}
- if (removeoldFlag == TRUE) {
- status = (unlink(linkName) && errno != ENOENT);
- if (status != 0) {
- perror(linkName);
- exit FALSE;
- }
+ if (opts & LN_VERBOSE) {
+ printf("'%s' -> '%s'\n", src, *argv);
}
- if (symlinkFlag == TRUE)
- status = symlink(*argv, linkName);
- else
- status = link(*argv, linkName);
- if (status != 0) {
- perror(linkName);
- exit FALSE;
+ if (link_func(*argv, src) != 0) {
+ bb_simple_perror_msg(src);
+ status = EXIT_FAILURE;
}
- }
- exit TRUE;
-}
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/
+ free(src_name);
+ } while ((++argv)[1]);
+
+ return status;
+}
projects / oweals / busybox.git / blobdiff