my $pid = fork();

my $report;
if (not defined $pid) {
    $report = "We were unable to process your file.\n";
    warn "$0: $!\n";   # put something in the web server errlog
}
elsif ($pid == 0) {
    # child process: launch the other executable
    open STDOUT, ">>", "/some/path/myfile.log";
    open STDERR, ">>", "/some/path/myfile.err";
    exec("/usr/local/bin/launch myfile");
}
else {
    # parent process: report the child process was launched
    $report = "Your file has been sent successfully.  You will be notified via email once it has been completed.  Thank you.";
}
print $report, end_html();