regex - Regular expression and repeating character classes in perl -

i trying write regular expression can extract (possibly multiple) strings of 4 hexadecimal numbers/letters.

i this: /^[a-fa-f0-9][a-fa-f0-9][a-fa-f0-9][a-fa-f0-9]/

but there better way?

it seems repeat operator:

a{n} matches 'a' repeated n times.

a{n,} matches 'a' repeated n or more times.

a{n, m} matches 'a' repeated between n , m times inclusive.

would work, following regular expression not seem work:

/^[a-fa-f0-9]{4}+/ 

i'm trying match strings like:

aa00

aa00ffaa

0011ffaa0022

and on. each string on it's own line.

thanks!

try this:

/^(?:[a-fa-f0-9]{4})+$/