^start of line
httpthe literal text http (case sensitive) s?optionally matches the literal s (11510 / 1638 / 7316) (case sensitive)
:the literal : (5810 / 728 / 3A16)
\/the literal / (4710 / 578 / 2F16)
\/the literal / (4710 / 578 / 2F16)
Group 1(.+\..{2,10}|localhost|(?:\d{1,3}\.){3}\d{1,3}) 1st Alternative.+\..{2,10} .+any character (except for line terminators), repeated at least once
\.the literal . (4610 / 568 / 2E16)
.{2,10}any character (except for line terminators), repeated between 2 and 10 times
localhostthe literal text localhost (case sensitive) 3rd Alternative(?:\d{1,3}\.){3}\d{1,3} Non-Capturing Group(?:\d{1,3}\.){3} {3}repeats the group contents below exactly 3 times:
\d{1,3}a digit, repeated between 1 and 3 times
\.the literal . (4610 / 568 / 2E16)
\d{1,3}a digit, repeated between 1 and 3 times
\/?optionally matches the literal / (4710 / 578 / 2F16)
.*?any character (except for line terminators), repeated any number of times
$end of line
g modifier: global. Finds all matches instead of stopping after the first
m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string