I've been doing some reading on regular expressions and thought I had everything covered, until recently.

I've had to filter out all strings of length 5 which end with the letter t and contain at least one dot inside. The problem arises when I try to limit the size of the string. It works just fine when I first filter out all strings of size 5 and then additionally do the filtering in accordance with the occurrence of a dot inside, but it's a hassle.

What would be the best way to accomplish this using one regex?

Thanks for any answers in advance!

  • Please post your code so we can look at it.
    – rahul
    Apr 29 '15 at 17:38

When you have an and of 2 constraints it is easier to work one at the time. Example:

grep '^....t$' | grep '\.'


perl -nlE '/^....t/ and /\./ and say '

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