Add has_path_prefix util

utils.c

@@ -112,6 +112,45 @@ strfreev (char **str_array)
     }
 }
 
+/* Compares if str has a specific path prefix. This differs
+   from a regular prefix in two ways. First of all there may
+   be multiple slashes separating the path elements, and
+   secondly, if a prefix is matched that has to be en entire
+   path element. For instance /a/prefix matches /a/prefix/foo/bar,
+   but not /a/prefixfoo/bar. */
+bool
+has_path_prefix (const char *str,
+                 const char *prefix)
+{
+  while (TRUE)
+    {
+      /* Skip consecutive slashes to reach next path
+         element */
+      while (*str == '/')
+        str++;
+      while (*prefix == '/')
+        prefix++;
+
+      /* No more prefix path elements? Done! */
+      if (*prefix == 0)
+        return TRUE;
+
+      /* Compare path element */
+      while (*prefix != 0 && *prefix != '/')
+        {
+          if (*str != *prefix)
+            return FALSE;
+          str++;
+          prefix++;
+        }
+
+      /* Matched prefix path element,
+         must be entire str path element */
+      if (*str != '/' && *str != 0)
+        return FALSE;
+    }
+}
+
 bool
 has_prefix (const char *str,
             const char *prefix)

utils.h

@@ -70,6 +70,8 @@ char* strdup_printf  (const char  *format,
                       ...);
 bool  has_prefix     (const char  *str,
                       const char  *prefix);
+bool  has_path_prefix (const char  *str,
+                       const char  *prefix);
 int   fdwalk         (int          proc_fd,
                       int        (*cb)(void *data, int fd),
                       void        *data);