You're close. 
unless ( $tax_collection =~ /^[a-zA-Z]+(?:,[a-zA-Z]+)*?$/ ) {
    print "<font color=\"#ff0000\"><i>Incorrect format</i></font>";
    $errors++;
}

[download]

What that does is it says match [a-zA-Z] as many times as possible (the first word) followed by a sequence that can be repeated as many times as necessary (or no times). That sequence may start with a comma, and finish with as many [a-zA-Z] characters as possible. The match is anchored from the front of the string to the end (assuming a single-line string).


Dave


"If I had my life to do over again, I'd be a plumber." -- Albert Einstein

In reply to Re: regex: only want [a-zA-Z] and comma chars in a string by davido
in thread regex: only want [a-zA-Z] and comma chars in a string by heezy

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