Question

I’d like to close STDOUT to prevent my code from outputing a particular image that I need for further computation but do not want on my web page.

So i want to close STDOUT, do what I have to do with my code, then reopen STDOUT to output stuff to a web page. (Not to a file)

What I tried is:

    close STDOUT;
    # my code here
    open STDOUT;

This doesn’t work…

Thanks

Answer 1

There are several ways to approach your problem, and many of them do not require you to close STDOUT and risk fubaring your program’s standard I/O channels.

For example, you can use the (1-arg) select command to direct the output of print commands somewhere else temporarily.

 print $stuff_you_want_to_send_to_STDOUT;

 select(NOT_STDOUT);
 # now default print sends things to NOT_STDOUT.
 # This doesn't need to be a real filehandle, though you may get warning
 # messages if it is not.
 ...;
 print $the_image_you_dont_want_to_go_to_STDOUT;
 ...;

 select(STDOUT);
 # now  print  sends things to STDOUT agin
 print $more_stuff_you_do_want_to_go_to_STDOUT;

You can also reassign the *STDOUT glob at run-time without closing any handles.

 *OLD_STDOUT = *STDOUT;
 print $for_STDOUT;

 *STDOUT = *NOT_STDOUT;     # again, doesn't need to be a real filehandle
 print $stuff_to_suppress;

 *STDOUT = *OLD_STDOUT;     # restore original STDOUT
 print $more_stuff_for_STDOUT;