Improve tar_getcwd

[chaz/tar] / src / misc.c

diff --git a/src/misc.c b/src/misc.c
index d68d80656c8d76f25c117b073c9e71e9e62785e5..bd396a307d2e37b0091262cd3e73092f54ef1899 100644 (file)
--- a/src/misc.c
+++ b/src/misc.c
@@ -283,21 +283,20 @@ normalize_filename (const char *name)
          getcwd is slow, it might fail, and it does not necessarily
          return a canonical name even when it succeeds.  Perhaps we
          can use dev+ino pairs instead of names?  */
-      copy = xgetcwd ();
-      if (copy)
-        {
-          size_t copylen = strlen (copy);
-          bool need_separator = ! (DOUBLE_SLASH_IS_DISTINCT_ROOT
-                                   && copylen == 2 && ISSLASH (copy[1]));
-          copy = xrealloc (copy, copylen + need_separator + strlen (name) + 1);
-          copy[copylen] = DIRECTORY_SEPARATOR;
-          strcpy (copy + copylen + need_separator, name);
-        }
-      else
-        WARN ((0, errno, _("Cannot get working directory")));
+      const char *cwd = tar_getcwd ();
+      size_t copylen;
+      bool need_separator;
+      
+      copylen = strlen (cwd);
+      need_separator = ! (DOUBLE_SLASH_IS_DISTINCT_ROOT
+                         && copylen == 2 && ISSLASH (cwd[1]));
+      copy = xmalloc (copylen + need_separator + strlen (name) + 1);
+      strcpy (copy, cwd);
+      copy[copylen] = DIRECTORY_SEPARATOR;
+      strcpy (copy + copylen + need_separator, name);
     }
 
-  if (! copy)
+  if (!copy)
     copy = xstrdup (name);
   normalize_filename_x (copy);
   return copy;
@@ -831,7 +830,8 @@ struct wd
 {
   /* The directory's name.  */
   char const *name;
-
+  /* Current working directory; initialized by tar_getcwd */
+  char *cwd; 
   /* If nonzero, the file descriptor of the directory, or AT_FDCWD if
      the working directory.  If zero, the directory needs to be opened
      to be used.  */
@@ -886,6 +886,7 @@ chdir_arg (char const *dir)
       if (! wd_count)
        {
          wd[wd_count].name = ".";
+         wd[wd_count].cwd = NULL;
          wd[wd_count].fd = AT_FDCWD;
          wd_count++;
        }
@@ -903,6 +904,7 @@ chdir_arg (char const *dir)
     }
 
   wd[wd_count].name = dir;
+  wd[wd_count].cwd = NULL;
   wd[wd_count].fd = 0;
   return wd_count++;
 }
@@ -976,6 +978,38 @@ chdir_do (int i)
     }
 }
 \f
+const char *
+tar_getcwd (void)
+{
+  static char *cwd;
+  namebuf_t nbuf;
+  int i;
+
+  if (!cwd)
+    cwd = xgetcwd ();
+  if (!wd)
+    return cwd;
+  
+  if (0 == chdir_current || !wd[chdir_current].cwd)
+    {
+      if (IS_ABSOLUTE_FILE_NAME (wd[chdir_current].name))
+       return wd[chdir_current].name;
+      
+      if (!wd[0].cwd)
+       wd[0].cwd = cwd;
+
+      for (i = chdir_current - 1; i > 0; i--)
+       if (wd[i].cwd)
+         break;
+      
+      nbuf = namebuf_create (wd[i].cwd);
+      for (i++; i <= chdir_current; i++)
+       namebuf_add_dir (nbuf, wd[i].name);
+      wd[chdir_current].cwd = namebuf_finish (nbuf);
+    }
+  return wd[chdir_current].cwd;
+}
+\f
 void
 close_diag (char const *name)
 {
@@ -1145,6 +1179,30 @@ namebuf_name (namebuf_t buf, const char *name)
   return buf->buffer;
 }
 
+void
+namebuf_add_dir (namebuf_t buf, const char *name)
+{
+  static char dirsep[] = { DIRECTORY_SEPARATOR, 0 };
+  if (!ISSLASH (buf->buffer[buf->dir_length - 1]))
+    {
+      namebuf_name (buf, dirsep);
+      buf->dir_length++;
+    }
+  namebuf_name (buf, name);
+  buf->dir_length += strlen (name);
+}
+
+char *
+namebuf_finish (namebuf_t buf)
+{
+  char *res = buf->buffer;
+  
+  if (ISSLASH (buf->buffer[buf->dir_length - 1]))
+    buf->buffer[buf->dir_length] = 0;
+  free (buf);
+  return res;
+}
+
 /* Return the filenames in directory NAME, relative to the chdir_fd.
    If the directory does not exist, report error if MUST_EXIST is
    true.