Merge pull request #7 from zakattacktwitter/master

Adding extname to complement basename.

Author: soumith

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]) ###
 

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},