regexp(n) on macOS
The text d827beb1f8eb, as Mac OS X 10.2.2, Mac OS X 10.2.1, Mac OS X 10.2 shipped it.
Match a regular expression against a string
Flags it lists
-
-- -
-about -
-all -
-expanded -
-indices -
-inline -
-line -
-lineanchor -
-linestop -
-nocase -
-start