Is there a way to get a copy of STDOUT without redirecting STDOUT? I wanted to capture the printouts from a sub that I cannot change. The following code is doing that (my thanks to others on this board for this code): 

#!/usr/bin/perl

use strict;
use warnings;

my ($buf);
{
  local *STDOUT;
  open( STDOUT, '>', \$buf ) or die "Write to buffer failed\n";
  mysub();
}

print "buffer: $buf\n";

sub mysub{
  print "mysub output\n";
}

[download]

The sub's printouts go to STDOUT, which is to my screen. Using the above code, STDOUT is redirected to the variable $buf so no printouts go to the screen. I want to be able to get a copy of the data that is going to STDOUT without redirecting STDOUT. In other words, I want the data to go to the variable "$buf" in the above code and to continue to go to the screen. Is there a way to do this?

I could just print the variable $buf after its done too. However, some of data are very big and the sub that I'm trying to capture takes a long time to execute. During that time, no printouts goes to the screen so there's nothing indicating that the program is still executing correctly.

Also, is there a way to capture STDERR at the same time? I mean, can I redirect a copy of STDERR and STDOUT to the same $variable? I was able to do it to two variables, but then, I don't know which error occur when. It would be nice to have the STDOUT and STDERR in the same spot in chronological order so I know which error occurred after which STDOUT data.

Thanks for any help.

MNJ

In reply to Need Help: Capture STDOUT without Redirecting by mnj200g

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