1st Capturing Group ((?:\d{2})(?:\:\d{2}){2})
Non-capturing group (?:\d{2})
\d
matches a digit (equivalent to [0-9]){2} matches the previous token exactly 2 times
Non-capturing group (?:\:\d{2}){2}
{2} matches the previous token exactly 2 times
\: matches the character : with index 5810 (3A16 or 728) literally (case sensitive)
\d
matches a digit (equivalent to [0-9]){2} matches the previous token exactly 2 times
.
matches any character (except for line terminators)*? matches the previous token between zero and unlimited times, as few times as possible, expanding as needed (lazy)
\[ matches the character [ with index 9110 (5B16 or 1338) literally (case sensitive)
\s matches any whitespace character (equivalent to [\r\n\t\f\v ])
2nd Capturing Group (\d+)
\d
matches a digit (equivalent to [0-9])+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
.
matches any character (except for line terminators)*? matches the previous token between zero and unlimited times, as few times as possible, expanding as needed (lazy)
\[ matches the character [ with index 9110 (5B16 or 1338) literally (case sensitive)
\s matches any whitespace character (equivalent to [\r\n\t\f\v ])
3rd Capturing Group (\d+)
\d
matches a digit (equivalent to [0-9])+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
g modifier: global. All matches (don't return after first match)
m modifier: multi line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)