open SH, "| /bin/sh" or die "can't launch subshell: $!";
for my $file ( @files ) {
    my $cmd = "perl -Ilib $file >> log\n";
    print STDERR $cmd;
    print SH $cmd; # stderr from subshell will go to STDERR
}
close SH;

##</code><code>##

 $ run-em-all.pl > log 2> errlog

##</code><code>##

    $cmd = "echo running $file 1>&2; perl -Ilib $file"
    print SH $cmd;