/* path-concat.c -- concatenate two arbitrary pathnames
- Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
+
+ Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 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
# include <config.h>
#endif
-#ifndef HAVE_MEMPCPY
-# define mempcpy(D, S, N) ((void *) ((char *) memcpy (D, S, N) + (N)))
-#endif
+/* Specification. */
+#include "path-concat.h"
-#include <stdio.h>
-#if HAVE_STRING_H
-# include <string.h>
-#endif
-#include <sys/types.h>
+#include <string.h>
-#ifndef HAVE_DECL_MALLOC
-"this configure-time declaration test was not run"
-#endif
-#if !HAVE_DECL_MALLOC
-char *malloc ();
-#endif
-
-#ifndef strdup
-char *strdup ();
-#endif
+#include "dirname.h"
+#include "xalloc.h"
-#ifndef DIRECTORY_SEPARATOR
-# define DIRECTORY_SEPARATOR '/'
+#if ! HAVE_MEMPCPY && ! defined mempcpy
+# define mempcpy(D, S, N) ((void *) ((char *) memcpy (D, S, N) + (N)))
#endif
-#ifndef ISSLASH
-# define ISSLASH(C) ((C) == DIRECTORY_SEPARATOR)
-#endif
+/* Return the longest suffix of F that is a relative file name.
+ If it has no such suffix, return the empty string. */
-#include "xalloc.h"
-#include "path-concat.h"
+static char const *
+longest_relative_suffix (char const *f)
+{
+ for (f += FILE_SYSTEM_PREFIX_LEN (f); ISSLASH (*f); f++)
+ continue;
+ return f;
+}
-/* Concatenate two pathname components, DIR and BASE, in
- newly-allocated storage and return the result. Return 0 if out of
- memory. Add a slash between DIR and BASE in the result if neither
- would contribute one. If each would contribute at least one, elide
- one from the end of DIR. Otherwise, simply concatenate DIR and
- BASE. In any case, if BASE_IN_RESULT is non-NULL, set
+/* Concatenate two pathname 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 BASE in the returned
concatenation.
- DIR may be NULL, BASE must not be.
-
- Return NULL if memory is exhausted. */
+ Report an error if memory is exhausted. */
char *
-path_concat (const char *dir, const char *base, char **base_in_result)
+path_concat (char const *dir, char const *abase, char **base_in_result)
{
+ char const *dirbase = base_name (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 = xmalloc (dirlen + needs_separator + baselen + 1);
char *p;
- char *p_concat;
- size_t base_len;
- size_t dir_len;
-
- if (!dir)
- {
- p_concat = strdup (base);
- if (base_in_result)
- *base_in_result = p_concat;
- return p_concat;
- }
-
- /* DIR is not empty. */
- base_len = strlen (base);
- dir_len = strlen (dir);
-
- p_concat = malloc (dir_len + base_len + 2);
- if (!p_concat)
- return 0;
-
- p = mempcpy (p_concat, dir, dir_len);
-
- if (dir_len > 0)
- {
- if (ISSLASH (*(p - 1)) && ISSLASH(*base))
- --p;
- else if (!ISSLASH (*(p - 1)) && !ISSLASH(*base))
- *p++ = DIRECTORY_SEPARATOR;
- }
+
+ p = mempcpy (p_concat, dir, dirlen);
+ *p = DIRECTORY_SEPARATOR;
+ p += needs_separator;
if (base_in_result)
*base_in_result = p;
- memcpy (p, base, base_len + 1);
+ p = mempcpy (p, base, baselen);
+ *p = '\0';
return p_concat;
}
-
-/* Same, but die when memory is exhausted. */
-
-char *
-xpath_concat (const char *dir, const char *base, char **base_in_result)
-{
- char *res = path_concat (dir, base, base_in_result);
- if (res)
- return res;
- xalloc_die ();
-}