What you probably want to do, is fork off the desired script, with SIG(CHLD) ignored, so it won't wait. Then, you close STDOUT and other filehandles in your cgi script, and the web server should close it off.

See Merlyn's Column 20

or this simpler example:

#!/usr/bin/perl 
use warnings;
use strict;

$| = 1;         # need either this or to explicitly flush stdout, etc.
# before forking
print "Content-type: text/plain\n\n";
print "Going to start the fork now\n";
if ( !defined(my $pid = fork())) {
print STDERR "fork error\n";
exit(1);
} elsif ($pid == 0) {
# child
close(STDOUT);close(STDIN);close(STDERR);
exec('./fork-long-process-test-process');     # lengthy processing
} else {
# parent
print "forked child \$pid= $pid\n";
exit 0;
}
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