#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11116125
use warnings;

print "one\n";
do { local *STDOUT; open STDOUT, '>', '/dev/null' or die; print "two\n
+"; };
print "three\n";
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do { local *STDOUT; open STDOUT, '>', '/dev/null' or die; print "two\n
+"; };
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You don't need a do{} block when just a bare block will do:

{ local *STDOUT; open STDOUT, '>', '/dev/null' or die; print "two\n"; 
+}
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Many thanks.

Initial response is "Doh!"

Second response: I knew I was becoming senile.

The documentation for open provides an example of duplicating and restoring filehandles:

    #!/usr/bin/perl
    open(my $oldout, ">&STDOUT")     or die "Can't dup STDOUT: $!";
    open(OLDERR,     ">&", \*STDERR) or die "Can't dup STDERR: $!";

    open(STDOUT, '>', "foo.out") or die "Can't redirect STDOUT: $!";
    open(STDERR, ">&STDOUT")     or die "Can't dup STDOUT: $!";

    select STDERR; $| = 1;  # make unbuffered
    select STDOUT; $| = 1;  # make unbuffered


    print STDOUT "stdout 1\n";  # this works for
    print STDERR "stderr 1\n";  # subprocesses too


    open(STDOUT, ">&", $oldout) or die "Can't dup \$oldout: $!";
    open(STDERR, ">&OLDERR")    or die "Can't dup OLDERR: $!";

    print STDOUT "stdout 2\n";
    print STDERR "stderr 2\n";
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If output is not going to an explicit filehandle but to the default filehandle (which happens at that moment to be STDOUT), then select may be of interest.

IMHO the best way is Capture::Tiny's capture_stdout, or capture if you want to grab STDERR as well.

Xilman:

For the FAQs, try perldoc perlfaq at the command prompt, it'll show you the overview of the FAQ lists, and show you the category of content in the various pages of FAQs, like:

    perlfaq1 - General Questions About Perl
    perlfaq2 - Obtaining and Learning about Perl
    perlfaq3 - Programming Tools
    perlfaq4 - Data Manipulation
    perlfaq5 - Files and Formats
    perlfaq6 - Regular Expressions
    perlfaq7 - General Perl Language Issues
    perlfaq8 - System Interaction
    perlfaq9 - Web, Email and Networking
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So for questions related to regular expressions, you'd check perldoc perlfaq6.

...roboticus

When your only tool is a hammer, all problems look like your thumb.

There's also the perldoc -q switch, which will cause a FAQ keyword search.

---

Give a man a fish:  <%-{-{-{-<

If you want even finer control over who prints, what gets printed and how, this may be of interest: Override printing to STDOUT/ERR. The bottomline is that you can "intercept" all calls to writing to STDOUT, check who the caller is and filter.

bw, bliako