findInPath(file, opt_checkCwd)code »
Searches the PATH environment variable for the given file.
Parameters
- filestring
- The file to locate on the PATH. 
- opt_checkCwdboolean=
- Whether to always start with the search with  the current working directory, regardless of whether it is explicitly  listed on the PATH. 
Returns
- ?string
- Path to the located file, or - nullif it could  not be found.