#!/usr/bin/perl -w
local (*SAVED_STDOUT);
open (SAVED_STDOUT, ">&STDOUT");

print "Roo";
close STDOUT;

open (STDOUT , ">>foo.bar") || die "$!";
print "s";
close STDOUT;

open(STDOUT, ">&SAVED_STDOUT");

print "ters\n

##</code><code>##

Here is a script that saves, redirects, and
restores STDOUT and STDERR:

#!/usr/bin/perl
open(OLDOUT, ">&STDOUT");
open(OLDERR, ">&STDERR");

open(STDOUT, '>', "foo.out") || die "Can't redirect stdout";
open(STDERR, ">&STDOUT")     || 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

close(STDOUT);
close(STDERR);

open(STDOUT, ">&OLDOUT");
open(STDERR, ">&OLDERR");

print STDOUT "stdout 2\n";
print STDERR "stderr 2\n";