You've placed code (push(@dic,$1);) inside the replacement part of the regular expression. Each three-letter code will be replaced by the string "push(@dic,$1);" instead of the code being executed, and because of that the string will never get shorter. Even though you could get the code to execute by adding the /e modifier on the regex, it still wouldn't do what you want (since the replacement value would be the return value of the push call), and so it's better to just move that code outside the regular expression.

Since you're matching three letters with your regular expression, and you want to replace those with the last two of those three letters, it's easier to just write it that way:

    while(length($line)>2){
        $line =~ s/([A-Z]([A-Z]{2}))/$2/;
        push(@dic, $1);
    }

[download]

I'm sure other monks will have (TI)MTOWTDI and more elegant solutions, but the above gets what you want with only a few changes.

In reply to Re: substitution in regular experssion by Anonymous Monk
in thread substitution in regular expression by aeqr

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