Please explain this Java regex

Question

I didn't write the following regex, and I'm trying to figure out what it does. I know that it must begin with policy-map and must have at least one space between policy-map and whatever comes next. But I'm stuck trying to figure out what the stuff inside the parenthesis means. I know that whatever it is, it has to be at the end of the line.

^policy-map\\s+([\\x21-\\x7e]{1,40})$

Thanks!

I highly recommend the following site: http://regex101.com/r/gV1hK3 — Firas Dib, Oct 01 '12 at 11:00

score 13 · Accepted Answer · answered Jul 17 '12 at 19:02

13

characters in range from hex 21 to hex 7e (basically printable, non-whitespace ascii) 1 to 40 times.

answered Jul 17 '12 at 19:02

Michael Krelin - hacker

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`[\\x21-\\x7e]` is commonly used to describe alphanumeric+special chars – Hans Z Jul 17 '12 at 19:03
1

This is the first time I've seen a regular expression written using hex. Thanks for your answer! – BJ Dela Cruz Jul 17 '12 at 19:07

score 8 · Answer 2 · edited Jul 17 '12 at 19:07

8

^ begin of string

policy-map constant

\s+ spaces

([\x21-\x7e]{1,40}) 1-40 symbols from \x21 to \x7e (i.e. all printable, non-whitespace ASCII characters including punctuation, upper and lower case letters and numbers)

$ end of string

edited Jul 17 '12 at 19:07

Mike Deck

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answered Jul 17 '12 at 19:03

burning_LEGION

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score 7 · Answer 3 · answered Jul 17 '12 at 19:06

^              Start of string
policy-map     "policy-map"
\\s+           One or more whitespace characters
(              Start of capture group 1
[\\x21-\\x7e]  From 1 to 40 characters in the range '\x21' to '\7E'
)              End of capture group 1
$              End of string

Please explain this Java regex

3 Answers3

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