- single KERNEL_VERSION(a,b,c) macro in platform.h

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

diff --git a/coreutils/ln.c b/coreutils/ln.c
index 6d41cce62c67dd07602379ebaf7f697d971b2997..229c682185ef029a0bb80deeacc05b30c23d453e 100644 (file)
--- a/coreutils/ln.c
+++ b/coreutils/ln.c
@@ -2,8 +2,7 @@
 /*
  * Mini ln implementation for busybox
  *
- * Copyright (C) 1999,2000,2001 by Lineo, inc.
- * Written by Erik Andersen <andersen@lineo.com>, <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
@@ -21,114 +20,99 @@
  *
  */
 
+/* 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 <string.h>
 #include <stdlib.h>
-#include <errno.h>
 #include <unistd.h>
+#include <errno.h>
 #include "busybox.h"
-#define BB_DECLARE_EXTERN
-#define bb_need_not_a_directory
-#include "messages.c"
-
 
-static const int LN_SYMLINK = 1;
-static const int LN_FORCE = 2;
-static const int LN_NODEREFERENCE = 4;
+#define LN_SYMLINK          1
+#define LN_FORCE            2
+#define LN_NODEREFERENCE    4
+#define LN_BACKUP           8
+#define LN_SUFFIX           16
 
-/*
- * 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 ln_main(int argc, char **argv)
 {
-       int status;
-       int src_is_dir;
+       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 *);
 
-       if (link_destname==NULL)
-               return(FALSE);
-
-       src_name = (char *) xmalloc(strlen(link_srcname)+strlen(link_destname)+1);
+       flag = bb_getopt_ulflags(argc, argv, "sfnbS:", &suffix);
 
-       if (link_srcname==NULL)
-               strcpy(src_name, link_destname);
-       else
-               strcpy(src_name, link_srcname);
+       if (argc == optind) {
+               bb_show_usage();
+       }
 
-       if (flag&LN_NODEREFERENCE)
-               src_is_dir = is_directory(src_name, TRUE, NULL);
-       else
-               src_is_dir = is_directory(src_name, FALSE, NULL);       
-       
-       if ((src_is_dir==TRUE)&&((flag&LN_NODEREFERENCE)==0)) {
-               char* srcdir_name;
+       last = argv[argc - 1];
+       argv += optind;
 
-               srcdir_name = xstrdup(link_destname);
-               strcat(src_name, "/");
-               strcat(src_name, get_last_path_component(srcdir_name));
-               free(srcdir_name);
-       }
-       
-       if (flag&LN_FORCE)
-               unlink(src_name);
-               
-       if (flag&LN_SYMLINK)
-               status = symlink(link_destname, src_name);
-       else
-               status = link(link_destname, src_name);
-
-       if (status != 0) {
-               perror_msg(src_name);
-               return(FALSE);
+       if (argc == optind + 1) {
+               *--argv = last;
+               last = bb_get_last_path_component(bb_xstrdup(last));
        }
-       return(TRUE);
-}
 
-extern 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();
+       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 (optind > (argc-1)) {
-               show_usage();
-       } 
-       if (optind == (argc-1)) {
-               if (fs_link(argv[optind], 
-                                       get_last_path_component(argv[optind]), flag)==FALSE)
+               if (!(flag & LN_SYMLINK) && stat(*argv, &statbuf)) {
+                       bb_perror_msg("%s", *argv);
                        status = EXIT_FAILURE;
-       }
-       while(optind<(argc-1)) {
-               if (fs_link(argv[optind], argv[argc-1], flag)==FALSE)
+                       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;
-               optind++;
-       }
-       exit(status);
-}
+               }
 
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/
+               free(src_name);
+
+       } while ((++argv)[1]);
+
+       return status;
+}