Optimize searches for directory structures by keeping a pointer to struct directory...

[chaz/tar] / src / misc.c

diff --git a/src/misc.c b/src/misc.c
index b56a916b1557a87175c5ea57e308a186c3259b67..a76b24eb6764cc85106c8bc38fbfa94f446f76f0 100644 (file)
--- a/src/misc.c
+++ b/src/misc.c
@@ -236,6 +236,25 @@ normalize_filename (const char *name)
   return zap_slashes (canonicalize_filename_mode (name, CAN_MISSING));
 }
 
+\f
+void
+replace_prefix (char **pname, const char *samp, size_t slen,
+               const char *repl, size_t rlen)
+{
+  char *name = *pname;
+  size_t nlen = strlen (name);
+  if (nlen > slen && memcmp (name, samp, slen) == 0 && ISSLASH (name[slen]))
+    {
+      if (rlen > slen)
+       {
+         name = xrealloc (name, nlen - slen + rlen + 1);
+         *pname = name;
+       }
+      memmove (name + rlen, name + slen, nlen - slen + 1);
+      memcpy (name, repl, rlen);
+    }
+}
+
 \f
 /* Handling numbers.  */
 
@@ -777,3 +796,4 @@ page_aligned_alloc (void **ptr, size_t size)
   *ptr = xmalloc (size1);
   return ptr_align (*ptr, alignment);
 }
+