[net.unix] regular expressions

lmc@denelcor.UUCP (Lyle McElhaney) (12/03/83)

In system 3 and 5, there are two sources for routines to compile and test
regular expressions. The first, contained in /usr/include/regexp.h and
described in regexp(7) ((5) in system 5) apparantly grew through the
v6-v7-Sys3 family, while the other, embodied in the PW library and described
in regcmp, regex(3X) came up via PWB-Sys3. The latter is more powerful,
with a grouping operator and a + operator (and different forms of () and {}).

My question is whether any Sys3 or 5 software actually uses the PWB version
as opposed to the v7 version. I know that most of the common users of REs
(ed, sed, grep, etc) use the v7 version. Is inclusion of the PWB version
in software left as an exercise for the student (not that I mind...)?

			Lyle McElhaney
			...(hao,nbires,brl-bmd)!denelcor!lmc

gwyn%brl-vld@sri-unix.UUCP (12/08/83)

From:      Doug Gwyn (VLD/VMB) <gwyn@brl-vld>

The PWB regcmp/regex is used only by "bfs" and "regcmp" UNIX System V
utilities.  With any luck -lPW will go away someday.