Your regex m/^[0-9a-fA-F]+/ doesn't match the empty string, so when you try to remove the last character your validation fails and the remove is disallowed.

Try return 0 unless( $_[0] =~ m/^[0-9a-fA-F]*/ ) instead.

In reply to Re: TK Entry - Validating Input by Crackers2
in thread TK Entry - Validating Input by Dirk80

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