]> Dogcows Code - chaz/tar/blobdiff - src/extract.c
(struct delayed_symlinks, extract_archive, apply_delayed_symlinks):
[chaz/tar] / src / extract.c
index 0f50d918c4e081937bf9454c8b969e5bfc47262f..d1401b32dcee13b0bf458550349a213d0f040908 100644 (file)
@@ -1,5 +1,8 @@
 /* Extract files from a tar archive.
-   Copyright 1988,92,93,94,96,97,98,99,2000,2001 Free Software Foundation, Inc.
+
+   Copyright 1988, 1992, 1993, 1994, 1996, 1997, 1998, 1999, 2000,
+   2001 Free Software Foundation, Inc.
+
    Written by John Gilmore, on 1985-11-19.
 
    This program is free software; you can redistribute it and/or modify it
@@ -71,8 +74,7 @@ struct delayed_symlink
     /* The next delayed symbolic link in the list.  */
     struct delayed_symlink *next;
 
-    /* The device, inode number and last-modified time of the
-       placeholder symbolic link.  */
+    /* The device, inode number and last-modified time of the placeholder.  */
     dev_t dev;
     ino_t ino;
     time_t mtime;
@@ -81,13 +83,22 @@ struct delayed_symlink
     uid_t uid;
     gid_t gid;
 
-    /* The location and desired target of the desired link, as two
-       adjacent character strings, both null-terminated. */
-    char names[1];
+    /* A list of sources for this symlink.  The sources are all to be
+       hard-linked together.  */
+    struct string_list *sources;
+
+    /* The desired target of the desired link.  */
+    char target[1];
   };
 
 static struct delayed_symlink *delayed_symlink_head;
 
+struct string_list
+  {
+    struct string_list *next;
+    char string[1];
+  };
+
 /*  Set up to extract files.  */
 void
 extr_init (void)
@@ -269,7 +280,8 @@ delay_set_stat (char const *file_name, struct stat const *stat_info,
                mode_t invert_permissions, enum permstatus permstatus)
 {
   size_t file_name_len = strlen (file_name);
-  struct delayed_set_stat *data = xmalloc (sizeof *data + file_name_len);
+  struct delayed_set_stat *data =
+    xmalloc (offsetof (struct delayed_set_stat, file_name) + file_name_len);
   data->file_name_len = file_name_len;
   strcpy (data->file_name, file_name);
   data->invert_permissions = invert_permissions;
@@ -281,9 +293,8 @@ delay_set_stat (char const *file_name, struct stat const *stat_info,
 
 /* Update the delayed_set_stat info for an intermediate directory
    created on the path to DIR_NAME.  The intermediate directory turned
-   out to be the same as this directory, e.g. due trailing slash or
-   ".." or symbolic links.  *DIR_STAT_INFO is the status of the
-   directory.  */
+   out to be the same as this directory, e.g. due to ".." or symbolic
+   links.  *DIR_STAT_INFO is the status of the directory.  */
 static void
 repair_delayed_set_stat (char const *dir_name,
                         struct stat const *dir_stat_info)
@@ -850,9 +861,9 @@ extract_archive (void)
        break;
 
       if (absolute_names_option
-         || (ISSLASH (current_link_name
-                      [FILESYSTEM_PREFIX_LEN (current_link_name)])
-             && ! contains_dot_dot (current_link_name)))
+         || (ISSLASH (current_link_name
+                        [FILESYSTEM_PREFIX_LEN (current_link_name)])
+               || contains_dot_dot (current_link_name)))
        {
          while (status = symlink (current_link_name, CURRENT_FILE_NAME),
                 status != 0)
@@ -891,7 +902,8 @@ extract_archive (void)
              size_t filelen = strlen (CURRENT_FILE_NAME);
              size_t linklen = strlen (current_link_name);
              struct delayed_symlink *p =
-               xmalloc (sizeof *p + filelen + linklen + 1);
+               xmalloc (offsetof (struct delayed_symlink, target)
+                        + linklen + 1);
              p->next = delayed_symlink_head;
              delayed_symlink_head = p;
              p->dev = st.st_dev;
@@ -899,8 +911,11 @@ extract_archive (void)
              p->mtime = st.st_mtime;
              p->uid = current_stat.st_uid;
              p->gid = current_stat.st_gid;
-             memcpy (p->names, CURRENT_FILE_NAME, filelen + 1);
-             memcpy (p->names + filelen + 1, current_link_name, linklen + 1);
+             p->sources = xmalloc (offsetof (struct string_list, string)
+                                   + filelen + 1);
+             p->sources->next = 0;
+             memcpy (p->sources->string, CURRENT_FILE_NAME, filelen + 1);
+             memcpy (p->target, current_link_name, linklen + 1);
              status = 0;
            }
        }
@@ -938,7 +953,24 @@ extract_archive (void)
        status = link (current_link_name, CURRENT_FILE_NAME);
 
        if (status == 0)
-         break;
+         {
+           struct delayed_symlink *ds = delayed_symlink_head;
+           if (ds && stat (current_link_name, &st1) == 0)
+             for (; ds; ds = ds->next)
+               if (ds->dev == st1.st_dev
+                   && ds->ino == st1.st_ino
+                   && ds->mtime == st1.st_mtime)
+                 {
+                   struct string_list *p = 
+                     xmalloc (offsetof (struct string_list, string)
+                              + strlen (CURRENT_FILE_NAME) + 1);
+                   strcpy (p->string, CURRENT_FILE_NAME);
+                   p->next = ds->sources;
+                   ds->sources = p;
+                   break;
+                 }
+           break;
+         }
        if (maybe_recoverable (CURRENT_FILE_NAME, &interdir_made))
          goto again_link;
 
@@ -951,9 +983,7 @@ extract_archive (void)
            && st1.st_ino == st2.st_ino)
          break;
 
-       ERROR ((0, e, _("%s: Cannot link to %s"),
-               quotearg_colon (CURRENT_FILE_NAME),
-               quote (current_link_name)));
+       link_error (current_link_name, CURRENT_FILE_NAME);
        if (backup_option)
          undo_last_backup ();
       }
@@ -1018,6 +1048,11 @@ extract_archive (void)
       name_length = strlen (CURRENT_FILE_NAME);
 
     really_dir:
+      /* Remove any redundant trailing "/"s.  */
+      while (FILESYSTEM_PREFIX_LEN (CURRENT_FILE_NAME) < name_length
+            && CURRENT_FILE_NAME[name_length - 1] == '/')
+       name_length--;
+      CURRENT_FILE_NAME[name_length] = '\0';
 
       if (incremental_option)
        {
@@ -1037,28 +1072,26 @@ extract_archive (void)
              & MODE_RWX);
 
     again_dir:
-      {
-       /* Do not pass redundant trailing "/" to mkdir, as POSIX does
-          not allow mkdir to ignore it.  */
-       size_t len = name_length;
-       char ch = '\0';
-       while (FILESYSTEM_PREFIX_LEN (CURRENT_FILE_NAME) < len
-              && CURRENT_FILE_NAME[len - 1] == '/')
-         len--, ch = '/';
-       CURRENT_FILE_NAME[len] = '\0';
-       status = mkdir (CURRENT_FILE_NAME, mode);
-       CURRENT_FILE_NAME[len] = ch;
-      }
+      status = mkdir (CURRENT_FILE_NAME, mode);
 
       if (status != 0)
        {
-         if (errno == EEXIST && interdir_made)
+         if (errno == EEXIST
+             && (interdir_made || old_files_option == OVERWRITE_OLD_FILES))
            {
              struct stat st;
              if (stat (CURRENT_FILE_NAME, &st) == 0)
                {
-                 repair_delayed_set_stat (CURRENT_FILE_NAME, &st);
-                 break;
+                 if (interdir_made)
+                   {
+                     repair_delayed_set_stat (CURRENT_FILE_NAME, &st);
+                     break;
+                   }
+                 if (S_ISDIR (st.st_mode))
+                   {
+                     mode = st.st_mode & ~ current_umask;
+                     goto directory_exists;
+                   }
                }
              errno = EEXIST;
            }
@@ -1075,10 +1108,11 @@ extract_archive (void)
            }
        }
 
+    directory_exists:
       if (status == 0
          || old_files_option == OVERWRITE_OLD_FILES)
        delay_set_stat (CURRENT_FILE_NAME, &current_stat,
-                       mode & ~ current_stat.st_mode,
+                       MODE_RWX & (mode ^ current_stat.st_mode),
                        (status == 0
                         ? ARCHIVED_PERMSTATUS
                         : UNKNOWN_PERMSTATUS));
@@ -1124,40 +1158,56 @@ extract_archive (void)
 static void
 apply_delayed_symlinks (void)
 {
-  struct delayed_symlink *p;
-  struct delayed_symlink *next;
+  struct delayed_symlink *ds;
 
-  for (p = delayed_symlink_head; p; p = next)
+  for (ds = delayed_symlink_head; ds; )
     {
-      char const *file = p->names;
-      struct stat st;
+      struct string_list *sources = ds->sources;
+      char const *valid_source = 0;
 
-      /* Before doing anything, make sure the placeholder file is still
-        there.  If the placeholder isn't there, don't worry about it, as
-        it may have been removed by a later extraction.  */
-      if (lstat (file, &st) == 0
-         && st.st_dev == p->dev
-         && st.st_ino == p->ino
-         && st.st_mtime == p->mtime)
+      for (sources = ds->sources; sources; sources = sources->next)
        {
-         if (unlink (file) != 0)
-           unlink_error (file);
-         else
+         char const *source = sources->string;
+         struct stat st;
+
+         /* Make sure the placeholder file is still there.  If not,
+            don't create a symlink, as the placeholder was probably
+            removed by a later extraction.  */
+         if (lstat (source, &st) == 0
+             && st.st_dev == ds->dev
+             && st.st_ino == ds->ino
+             && st.st_mtime == ds->mtime)
            {
-             char const *contents = file + strlen (file) + 1;
-             if (symlink (contents, file) != 0)
-               symlink_error (contents, file);
+             /* Unlink the placeholder, then create a hard link if possible,
+                a symbolic link otherwise.  */
+             if (unlink (source) != 0)
+               unlink_error (source);
+             else if (valid_source && link (valid_source, source) == 0)
+               ;
+             else if (symlink (ds->target, source) != 0)
+               symlink_error (ds->target, source);
              else
                {
-                 st.st_uid = p->uid;
-                 st.st_gid = p->gid;
-                 set_stat (file, &st, 0, 0, SYMTYPE);
+                 valid_source = source;
+                 st.st_uid = ds->uid;
+                 st.st_gid = ds->gid;
+                 set_stat (source, &st, 0, 0, SYMTYPE);
                }
            }
        }
 
-      next = p->next;
-      free (p);
+      for (sources = ds->sources; sources; )
+       {
+         struct string_list *next = sources->next;
+         free (sources);
+         sources = next;
+       }
+
+      {
+       struct delayed_symlink *next = ds->next;
+       free (ds);
+       ds = next;
+      }
     }
 
   delayed_symlink_head = 0;
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