I'm a worry-wart about later needed changes. So rather than going for terser, I'd write: 
    if ($x eq 'key_1') {
        DoaBunchOfStuff( $x );
    } else {
        foreach $key (keys %my_hash) {
            DoaBunchOfStuff( $key );
        }
    }

[download]

In reply to Re: Loop once on condition 1, many times on cond. 2? by apl
in thread Loop once on condition 1, many times on cond. 2? by punch_card_don

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