Merge pull request #7 from zakattacktwitter/master

Adding extname to complement basename.

2 files changed, 23 insertions, 0 deletions

diff --git a/README.md b/README.md
index 7c9d606..6b22d18 100644
--- a/README.md
+++ b/README.md
@@ -41,6 +41,11 @@ This is similar to the well know shell command `"basename"`.
 Return the name of directory containing file `path`.
 This is similar to the well known shell command `"dirname"`.
 
+<a name="paths.extname"/>
+### paths.extname(path) ###
+
+Return the extension of the `path` or nil if none is found.
+
 <a name="paths.concat"/>
 ### paths.concat([path1,....,pathn]) ###
 
diff --git a/paths.c b/paths.c
index 910f76a..ee6a86b 100644
--- a/paths.c
+++ b/paths.c
@@ -339,6 +339,23 @@ lua_dirname(lua_State *L)
 }
 
 
+static int
+lua_extname(lua_State *L)
+{
+  const char *fname = luaL_checkstring(L, 1);
+  const char *p;
+
+  p = fname + strlen(fname) - 1;
+  while (p >= fname) {
+    if (*p == '.') {
+      lua_pushstring(L, p + 1);
+      return 1;
+    }
+    p--;
+  }
+  return 0;
+}
+
 
 /* ------------------------------------------------------ */
 /* cwd and concat */
@@ -1095,6 +1112,7 @@ static const struct luaL_Reg paths__ [] = {
   {"dirp", lua_dirp},
   {"basename", lua_basename},
   {"dirname", lua_dirname},
+  {"extname", lua_extname},
   {"cwd", lua_cwd},
   {"concat", lua_concatfname},
   {"execdir", lua_execdir},