Please make a new topic instead of reviving old ones.
From within a child script, or from within a plugin, the output of print or printf commands go to the console.
on Windows, the console is hidden by default. You can make it visible via the user settings dialog.
on Mac, the output goes to the system console, but are delayed. The best is to open a terminal, start V-REP with ./vrep.app/Contents/MacOS/vrep. Then all the console outputs are correctly displayed.
on Linux, the output goes to the console/terminal from where you start V-REP