#!/usr/bin/perl -snl

BEGIN{
    for ($N) {
        s/[10]//g;
        s/2/[abc]/g;
        s/3/[def]/g;
        s/4/[ghi]/g;
        s/5/[jkl]/g;
        s/6/[mno]/g;
        s/7/[pqrs]/g;
        s/8/[tuv]/g;
        s/9/[wxyz]/g
    }
}

/^$N$/oi&&print


##</code><code>##

    phonenum -N=7375 /usr/dict/words