====== 批次修改檔名 ======
將檔案名末端的 .ptt.htm 改成 .ppt
<code>
foreach my $file (glob "*.ppt.htm") {
    my $newfile = $file;
    $newfile =~ s/\.htm//;
    if (-e $newfile) {
        warn "wrong!!!\n";
    } elsif (rename $file, $newfile) {
    } else {
        warn "failed!!!\n";
    }
}
</code>