code: function pidOf( procName, callback ){
      if ( isString( procName )){
          var pids = [];
  
          procStat( procName, function( err, processes ){
              processes.object.forEach( function( proc ){
                  pids.push( proc.pid )
              });
  
              callback( err, pids )
          })
      } else callback( new Error( 'A non-string process name was supplied' ), null, null )
  }
docs: Search for one or more PIDs that match a give process name