That only gets the file path though the map name will always be an empty string. I would probably suggest creating a function called something like "get_map_maxrounds_config" with the map name as the argument. Here is a basic outline of a function that will do what you want:
PHP Code:
get_map_maxrounds_config(szMapname[])
{
// Get the file name just like you did already
// Open the file
// Loop through the file's lines
// Parse each line
// if first parameter is "mp_maxrounds"
// read second parameter, store it in a variable
// Close file
// return mp_maxrounds variable
}