How do I parse a file name format like 'PUBLIC001' with a Regular Expression?

Need help with a regular expression that parses a file name

File will be named PUBLIC001
‘PUBLIC’ is static text in all file names
Last 3 digits- day of the year.001(Jan 1)-366(Dec31st on a leap year) is valid range

What would be regular expression. Is there a way to limit the max to 366?

THanks

>Solution :

A pattern like:

 PUBLIC([0-2]\d\d|3[0-5]\d|36[0-6])

would do it.

Or if validating the date number doesn’t matter, then something like:

PUBLIC\d\d\d

or

PUBLIC\d{3}

would do it too.

Add a ^ and $ to the beginning and end, respectively, if the file should not have any other parts to it (e.g., this will avoid matching NOT-PUBLIC001, or PUBLIC001002)

like:

^PUBLIC\d{3}$