# See the Cookbook p.263 for redirecting standard output. 
# Copy the STDOUT file descriptors:
my $buffer_file = '/path/to/buffer.txt';
open(OLDOUT, ">&STDOUT");
open(STDOUT, "> $buffer_file") or die "Couldn't redirect STDOUT to $buffer_file: $!";

# Call the script whose output I want to capture:
do("/path/to/cgi/mhandler.cgi");

# Close the redirected STDOUT and restore the original:	
close(STDOUT) or die "Couldn't close redirected STDOUT: $!";
open(STDOUT, ">&OLDOUT") or die "Couldn't restore STDOUT: $!";
close(OLDOUT) or die "Couldn't close OLDOUT: $!";