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How to restore from redirecting STDOUT to variable?

by anaconda_wly (Scribe)
on Jan 17, 2013 at 02:36 UTC ( #1013683=perlquestion: print w/ replies, xml ) Need Help??
anaconda_wly has asked for the wisdom of the Perl Monks concerning the following question:

I use code below directing output to $output, and I can't see screen display any more. How can I restore from it to a normal state which will print to the screen? I tried close STDOUT but no effect.

close STDOUT; my $output = ""; open(STDOUT, ">", \$output) or die "Can't open STDOUT: $!"; print "test \n";
close STDOUT;//no effect

Thanks!

Comment on How to restore from redirecting STDOUT to variable?
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Re: How to restore from redirecting STDOUT to variable?
by choroba (Abbot) on Jan 17, 2013 at 02:45 UTC
    Read open. The examples are there:
    #!/usr/bin/perl use warnings; use strict; open my $save_out, '>&', \*STDOUT or die "Can't dup STDOUT: $!"; close STDOUT; my $output; open STDOUT, '>', \$output or die "Can't open STDOUT: $!"; print "test \n"; close STDOUT; open STDOUT, '>&', $save_out or die "Can't restore STDOUT: $!"; print "Back\n"; print $output;
    لսႽ ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ
      Thanks! What's exactly the "&" means after ">"?

        That you want the file descriptor dup()ed, i.e. get a new file descriptor that refers to the same output stream as STDERR and a Perl-level file handle layered on top of that.

        As the open() perldoc also explains, this is even better written with an '=' after the ampersand:

        open my $save_out, '>&=', \*STDOUT or die "Can't fdopen STDOUT: $!"; open STDOUT, '>&=', $save_out or die "Can't restore STDOUT: $!";
        This avoids creating an all new file descriptor but reuses the system's for a new Perl file handle.

Re: How to restore from redirecting STDOUT to variable?
by Anonymous Monk on Jan 17, 2013 at 03:07 UTC

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