Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!bellcore!faline!thumper!ulysses!andante!alice!andrew
From: andrew@alice.UUCP (Andrew Hume)
Newsgroups: comp.unix.wizards
Subject: Re: what should egrep '|root' /etc/passwd print?
Summary: obvious but not useful
Message-ID: <8209@alice.UUCP>
Date: 16 Sep 88 21:51:14 GMT
References: <44414@beno.seismo.CSS.GOV> <68203@sun.uucp> <8202@alice.UUCP> <410@quintus.UUCP>
Organization: AT&T Bell Laboratories, Murray Hill NJ
Lines: 13



it sounds appealing to allow a missing RE to mean the empty string
but i am unconvinced as to its utility. the examples show this; there
is little to choose between
	grep -c '' and grep -c '^'
for counting lines. the latter is one char longer but needs no new concepts.
if the example you realy want to work is
	ls | egrep '\.c(|\.BAK)$'	- find *.c and *.c.BAK files
then you can do that with the current egrep by
	ls | egrep '\.c(\.BAK)?$'
this time the patterns are the same length but no new concepts required.
can anyone think of other useful meanings for the null RE?