You can localize the STDOUT filehandle and change the typeglob...

open(FOO,">/temp/foo") || die $!;
sub foo { local *STDOUT=*FOO; print "foo"; } #yes, this is supposedly 
+to STDOUT
foo;
close(FOO);
[download]

Similar would be something like :

*FOO=*STDOUT; #Save it somehow
open(STDOUT,">>outputfile") || die $!;
sub foo { print "foo bar"; }
foo;
close(STDOUT);
*STDOUT=*FOO;
[download]

Greetz
Beatnik
... Quidquid perl dictum sit, altum viditur.