Hi qazwart,

The following code is based on an example in the documentation from perlfaq8 (under the question "How can I capture STDERR from an external command?"): 

#!/usr/bin/perl -w

# Strict
use strict;
use warnings;

# Libraries
use IPC::Open3;
use Symbol qw(gensym);
use IO::File;

####################
### Main program ###
####################

# User-defined
my $module = "mymodule";
my $OLD    = "1.41";
my $NEW    = "1.42";
my $cmd    = "cvs rlog -r${OLD}::${NEW} -SN $module";

local *CATCHOUT = IO::File->new_tmpfile;
local *CATCHERR = IO::File->new_tmpfile;
my $pid = open3(gensym(), ">&CATCHOUT", ">&CATCHERR", $cmd);
waitpid($pid, 0);
seek(\*CATCHOUT, 0, 0);
seek(\*CATCHERR, 0, 0);
process_stdout(*CATCHOUT);
process_stderr(*CATCHERR);

sub process_stdout {
    my ($outfh) = @_;
    while (my $line = <$outfh>) {
        #  Handle $line from STDOUT
        chomp $line;
        print "\e[102m$line\e[m\n";  # Change this
    }
}

sub process_stderr {
    my ($errfh) = @_;
    while (my $line = <$errfh>) {
        #  Handle $line from STDERR
        chomp $line;
        print "\e[101m$line\e[m\n";  # Change this
    }
}

[download]

I even tested it on a cvs module locally to make sure it handles both STDOUT and STDERR from the cvs rlog command correctly.

At the moment, it's just displaying the lines it reads (in different colors; green for STDOUT, red for STDERR), but you can modify the 2 lines marked "Change this" above to suit your needs.

s''(q.S:$/9=(T1';s;(..)(..);$..=substr+crypt($1,$2),2,3;eg;print$..$/

In reply to Re: Parsing STDERR and STDOUT at the same time by liverpole
in thread Parsing STDERR and STDOUT at the same time by qazwart

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