# Perl 5 
    @cmd = ('get','put','try','find','copy','fold','spindle','mutilate');
    $cmd = join '|', map { quotemeta $_ } @cmd;

    $str =~ / (?:$cmd) \( .*? \) /;

##</code><code>##

    $deleteline = rx/^^ \< <sp> (\N* \n) /
    $appendline = rx/^^ \> <sp> (\N* \n) /

##</code><code>##

    $text =~ /<Diff.file>/;         # Invoke through grammar

##</code><code>##

... $0/2002/08/22/exegesis5.html{hunk} ...

##</code><code>##

# Perl 5
$str =~ m/ ^ m* (?:d?c{0,3}|c[dm]) (?:l?x{0,3}|x[lc]) (?:v?i{0,3}|i[vx]) $ /ix;

# Perl 6
$str =~ m:i/ ^ m* [d?c<0,3>|c<[dm]>] [l?x<0,3>|x<[lc]>] [v?i<0,3>|i<[vx]>] $ /;