tar-1.29HEADtar-1.29master

1 files changed, 88 insertions, 0 deletions

diff --git a/gnu/filenamecat-lgpl.c b/gnu/filenamecat-lgpl.c
new file mode 100644
index 0000000..a359a51
--- /dev/null
+++ b/gnu/filenamecat-lgpl.c
@@ -0,0 +1,88 @@
+/* Concatenate two arbitrary file names.
+
+   Copyright (C) 1996-2007, 2009-2015 Free Software Foundation, Inc.
+
+   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 3 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, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Jim Meyering.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "filenamecat.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "dirname.h"
+
+#if ! HAVE_MEMPCPY && ! defined mempcpy
+# define mempcpy(D, S, N) ((void *) ((char *) memcpy (D, S, N) + (N)))
+#endif
+
+/* Return the longest suffix of F that is a relative file name.
+   If it has no such suffix, return the empty string.  */
+
+static char const * _GL_ATTRIBUTE_PURE
+longest_relative_suffix (char const *f)
+{
+  for (f += FILE_SYSTEM_PREFIX_LEN (f); ISSLASH (*f); f++)
+    continue;
+  return f;
+}
+
+/* Concatenate two file name components, DIR and ABASE, in
+   newly-allocated storage and return the result.
+   The resulting file name F is such that the commands "ls F" and "(cd
+   DIR; ls BASE)" refer to the same file, where BASE is ABASE with any
+   file system prefixes and leading separators removed.
+   Arrange for a directory separator if necessary between DIR and BASE
+   in the result, removing any redundant separators.
+   In any case, if BASE_IN_RESULT is non-NULL, set
+   *BASE_IN_RESULT to point to the copy of ABASE in the returned
+   concatenation.  However, if ABASE begins with more than one slash,
+   set *BASE_IN_RESULT to point to the sole corresponding slash that
+   is copied into the result buffer.
+
+   Return NULL if malloc fails.  */
+
+char *
+mfile_name_concat (char const *dir, char const *abase, char **base_in_result)
+{
+  char const *dirbase = last_component (dir);
+  size_t dirbaselen = base_len (dirbase);
+  size_t dirlen = dirbase - dir + dirbaselen;
+  size_t needs_separator = (dirbaselen && ! ISSLASH (dirbase[dirbaselen - 1]));
+
+  char const *base = longest_relative_suffix (abase);
+  size_t baselen = strlen (base);
+
+  char *p_concat = malloc (dirlen + needs_separator + baselen + 1);
+  char *p;
+
+  if (p_concat == NULL)
+    return NULL;
+
+  p = mempcpy (p_concat, dir, dirlen);
+  *p = DIRECTORY_SEPARATOR;
+  p += needs_separator;
+
+  if (base_in_result)
+    *base_in_result = p - IS_ABSOLUTE_FILE_NAME (abase);
+
+  p = mempcpy (p, base, baselen);
+  *p = '\0';
+
+  return p_concat;
+}