Getting STDOUT, STDERR, and response code from external *nix command in perl

Question

I want to execute an external command from within my Perl script, putting the output of both stdout and stderr into a $variable of my choice, and to get the com

Answer 1

A frequently given answer to this question is to use a command line containing shell type redirection. However, suppose you want to avoid that, and use open() with a command and argument list, so you have to worry less about how a shell might interpret the input (which might be partly made up of user-supplied values). Then without resorting to packages such as IPC::Open3, the following will read both stdout and stderr:

my ($child_pid, $child_rc);

unless ($child_pid = open(OUTPUT, '-|')) {
  open(STDERR, ">&STDOUT");
  exec('program', 'with', 'arguments');
  die "ERROR: Could not execute program: $!";
}
waitpid($child_pid, 0);
$child_rc = $? >> 8;

while (
) {
  # Do something with it
}
close(OUTPUT);