hush_test: stop mixing tabs/spaces for indentation

[oweals/busybox.git] / coreutils / ln.c

diff --git a/coreutils/ln.c b/coreutils/ln.c
index 62496fba09b84b779784647112e9892683fafdc5..eb7171959cbe62b479753124fb817eda6df90309 100644 (file)
--- a/coreutils/ln.c
+++ b/coreutils/ln.c
@@ -1,95 +1,109 @@
+/* vi: set sw=4 ts=4: */
 /*
  * Mini ln implementation for busybox
  *
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
  *
- * Copyright (C) 1999 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
- *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include "internal.h"
-#include <stdio.h>
-#include <dirent.h>
-#include <errno.h>
-
+/* BB_AUDIT SUSv3 compliant */
+/* BB_AUDIT GNU options missing: -d, -F, -i, and -v. */
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/ln.html */
 
-static const char ln_usage[] = "ln [OPTION] TARGET... LINK_NAME|DIRECTORY\n"
-"Create a link named LINK_NAME or DIRECTORY to the specified TARGET\n"
-"\nOptions:\n"
-"\t-s\tmake symbolic links instead of hard links\n"
-"\t-f\tremove existing destination files\n";
+#include "libbb.h"
 
+/* This is a NOEXEC applet. Be very careful! */
 
-static int symlinkFlag = FALSE;
-static int removeoldFlag = FALSE;
 
+#define LN_SYMLINK          1
+#define LN_FORCE            2
+#define LN_NODEREFERENCE    4
+#define LN_BACKUP           8
+#define LN_SUFFIX           16
 
-extern int ln_main(int argc, char **argv)
+int ln_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int ln_main(int argc, char **argv)
 {
-    int status;
-    static char* linkName;
-
-    if (argc < 3) {
-       usage (ln_usage);
-    }
-    argc--;
-    argv++;
-
-    /* Parse any options */
-    while (**argv == '-') {
-       while (*++(*argv))
-           switch (**argv) {
-           case 's':
-               symlinkFlag = TRUE;
-               break;
-           case 'f':
-               removeoldFlag = TRUE;
-               break;
-           default:
-               usage (ln_usage);
-           }
-       argc--;
-       argv++;
-    }
-
-
-    linkName = argv[argc - 1];
-
-    if ((argc > 3) && !(isDirectory(linkName))) {
-       fprintf(stderr, "%s: not a directory\n", linkName);
-       exit (FALSE);
-    }
-
-    while (argc-- >= 2) {
-       if (removeoldFlag==TRUE ) {
-           status = ( unlink(linkName) && errno != ENOENT );
-           if ( status != 0 ) {
-               perror(linkName);
-               exit( FALSE);
-           }
+       int status = EXIT_SUCCESS;
+       int flag;
+       char *last;
+       char *src_name;
+       char *src;
+       char *suffix = (char*)"~";
+       struct stat statbuf;
+       int (*link_func)(const char *, const char *);
+
+       flag = getopt32(argv, "sfnbS:", &suffix);
+
+       if (argc == optind) {
+               bb_show_usage();
        }
-       if ( symlinkFlag==TRUE)
-               status = symlink(*argv, linkName);
-       else
-               status = link(*argv, linkName);
-       if ( status != 0 ) {
-           perror(linkName);
-           exit( FALSE);
+
+       last = argv[argc - 1];
+       argv += optind;
+
+       if (argc == optind + 1) {
+               *--argv = last;
+               last = bb_get_last_path_component_strip(xstrdup(last));
        }
-    }
-    exit( TRUE);
+
+       do {
+               src_name = NULL;
+               src = last;
+
+               if (is_directory(src,
+                               (flag & LN_NODEREFERENCE) ^ LN_NODEREFERENCE,
+                               NULL)
+               ) {
+                       src_name = xstrdup(*argv);
+                       src = concat_path_file(src, bb_get_last_path_component_strip(src_name));
+                       free(src_name);
+                       src_name = src;
+               }
+               if (!(flag & 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 (flag & 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 (flag & LN_FORCE) {
+                       unlink(src);
+               }
+
+               link_func = link;
+               if (flag & LN_SYMLINK) {
+                       link_func = symlink;
+               }
+
+               if (link_func(*argv, src) != 0) {
+                       bb_simple_perror_msg(src);
+                       status = EXIT_FAILURE;
+               }
+
+               free(src_name);
+
+       } while ((++argv)[1]);
+
+       return status;
 }