CODEWITHSUNDEEP
regex
David542
David542

Reputation: 110203

Shorten a regex for HH:MM:SS

is there a way to shorten the following to find a time in the format HH:MM:SS?

'^[0-6][0-9]:[0-6][0-9]:[0-6][0-9]$'

Upvotes: 0

Views: 1633

Answers (2)

Phrogz
Phrogz

Reputation: 303254

Assuming you don't need to do validation of the values, but just find things that look like times, how about just:

\d{1,2}:\d{2}:\d{2}

If you are searching through text to find values you don't really want to anchor at ^ and $ unless your regex flavor has those matching at the beginning and end of line, and your source data has these on their own lines.

Upvotes: 1

sarnold
sarnold

Reputation: 104070

If anything, it ought to be longer, since 69:69:69 does not make sense as a time.

([01]\d|2[0-3]):([0-5]\d|60):([0-5]\d|60)
allow 00-23     00-59 and 60 00-59 and 60
                ~~~~~~~~~~~~~~~~~~~~~~~~~
                60 is useful for supporting leap seconds

If you really want your example, but shorter, you can do it:

[0-6]\d(:[0-6]\d){2}
     ~~          ~~~
      |          exactly two repetitions of preceding () block
      Matches digits in many regex implementations

Upvotes: 2

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