nl_tokens: Spawn a binary and read its stdout .
pl_tokens: function run ( cmd , args , options , done ) { if ( typeof options === 'function' ) { done = options ; options = undefined ; } var executed = false ; var ch = spawn ( cmd , args , options ) ; var stdout = '' ; var stderr = '' ; ch . stdout . on ( 'data' , function ( d ) { stdout += d . toString ( ) ; } ) ; ch . stderr . on ( 'data' , function ( d ) { stderr += d . toString ( ) ; } ) ; ch . on ( 'error' , function ( err ) { if ( executed ) return ; executed = true ; done ( new <mask> ( err ) ) ; } ) ; ch . on ( 'close' , function ( code ) { if ( executed ) return ; executed = true ; if ( stderr ) { return done ( new Error ( stderr ) ) ; } done ( null , stdout , code ) ; } ) ; }