- patch from Denis Vlasenko to add and use bb_xchdir()

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

diff --git a/coreutils/ln.c b/coreutils/ln.c
index cd3cb4e450f86e12caa3b1ca48f183c8e29e8df2..229c682185ef029a0bb80deeacc05b30c23d453e 100644 (file)
--- a/coreutils/ln.c
+++ b/coreutils/ln.c
@@ -1,7 +1,8 @@
+/* vi: set sw=4 ts=4: */
 /*
  * Mini ln implementation for busybox
  *
- * Copyright (C) 1998 by Erik Andersen <andersee@debian.org>
+ * Copyright (C) 1999-2004 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
@@ -19,82 +20,99 @@
  *
  */
 
-#include "internal.h"
+/* BB_AUDIT SUSv3 compliant */
+/* BB_AUDIT GNU options missing: -d, -F, -i, and -v. */
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/ln.html */
+
 #include <stdio.h>
-#include <dirent.h>
+#include <stdlib.h>
+#include <unistd.h>
 #include <errno.h>
+#include "busybox.h"
 
+#define LN_SYMLINK          1
+#define LN_FORCE            2
+#define LN_NODEREFERENCE    4
+#define LN_BACKUP           8
+#define LN_SUFFIX           16
 
-static const char ln_usage[] = "ln [-s] [-f] original-name additional-name\n"
-"\n"
-"\tAdd a new name that refers to the same file as \"original-name\"\n"
-"\n"
-"\t-s:\tUse a \"symbolic\" link, instead of a \"hard\" link.\n"
-"\t-f:\tRemove existing destination files.\n";
+int ln_main(int argc, char **argv)
+{
+       int status = EXIT_SUCCESS;
+       int flag;
+       char *last;
+       char *src_name;
+       char *src;
+       char *suffix = "~";
+       struct stat statbuf;
+       int (*link_func)(const char *, const char *);
 
+       flag = bb_getopt_ulflags(argc, argv, "sfnbS:", &suffix);
 
-static int symlinkFlag = FALSE;
-static int removeoldFlag = FALSE;
-static const char *destName;
+       if (argc == optind) {
+               bb_show_usage();
+       }
 
+       last = argv[argc - 1];
+       argv += optind;
 
-extern int ln_main(int argc, char **argv)
-{
-    int status;
-    char newdestName[NAME_MAX];
-
-    if (argc < 3) {
-       fprintf(stderr, "Usage: %s", ln_usage);
-       exit (FALSE);
-    }
-    argc--;
-    argv++;
-
-    /* Parse any options */
-    while (**argv == '-') {
-       while (*++(*argv))
-           switch (**argv) {
-           case 's':
-               symlinkFlag = TRUE;
-               break;
-           case 'f':
-               removeoldFlag = TRUE;
-               break;
-           default:
-               fprintf(stderr, "Usage: %s\n", ln_usage);
-               exit(FALSE);
-           }
-       argc--;
-       argv++;
-    }
-
-
-    destName = argv[argc - 1];
-
-    if ((argc > 3) && !(isDirectory(destName))) {
-       fprintf(stderr, "%s: not a directory\n", destName);
-       exit (FALSE);
-    }
-
-    while (argc-- >= 2) {
-       strcpy(newdestName, destName);
-       strcat(newdestName, (*argv)+(strlen(*(++argv))));
-       
-       if (removeoldFlag==TRUE ) {
-           status = ( unlink(newdestName) && errno != ENOENT );
-           if ( status != 0 ) {
-               perror(newdestName);
-               exit( FALSE);
-           }
+       if (argc == optind + 1) {
+               *--argv = last;
+               last = bb_get_last_path_component(bb_xstrdup(last));
        }
-       if ( symlinkFlag==TRUE)
-               status = symlink(*argv, newdestName);
-       else
-               status = link(*argv, newdestName);
-       if ( status != 0 ) {
-           perror(newdestName);
-           exit( FALSE);
-       }
-    }
-    exit( TRUE);
+
+       do {
+               src_name = NULL;
+               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 = src;
+               }
+               if (!(flag & LN_SYMLINK) && stat(*argv, &statbuf)) {
+                       bb_perror_msg("%s", *argv);
+                       status = EXIT_FAILURE;
+                       free(src_name);
+                       continue;
+               }
+
+               if (flag & LN_BACKUP) {
+                               char *backup;
+                               backup = bb_xasprintf("%s%s", src, suffix);
+                               if (rename(src, backup) < 0 && errno != ENOENT) {
+                                               bb_perror_msg("%s", 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_perror_msg("%s", src);
+                       status = EXIT_FAILURE;
+               }
+
+               free(src_name);
+
+       } while ((++argv)[1]);
+
+       return status;
 }