code: public File pathToFile( String fileName )
          throws IOException
      {
          String cwd = (String)getu("bsh.cwd");
          File file = new File( fileName );
  
          // if relative, fix up to bsh.cwd
          if ( !file.isAbsolute() ) {
              file = new File( cwd + File.separator + fileName );
          }
  
          return new File( file.getCanonicalPath() );
      }
docs: Localize a path to the file name based on the bsh.cwd interpreter
  working directory.