grep replacement

[andrew at alice.UUCP]

	Al Aho and I are designing a replacement for grep, egrep and fgrep.
The question is what flags should it support and what kind of patterns
should it handle? (Assume the existence of flags to make it compatible
with grep, egrep and fgrep.)
	The proposed flags are the V9 flags:
-f file	pattern is (`cat file`)
-v	print nonmatching
-i	ignore aphabetic case
-n	print line number
-x	the pattern used is ^pattern$
-c	print count only
-l	print filenames only
-b	print block numbers
-h	do not print filenames in front of matching lines
-H	always print filenames in front of matching lines
-s	no output; just status
-e expr	use expr as the pattern

The patterns are as for egrep, supplemented by back-referencing
as in \{pattern\}\1.

please send your comments about flags or patterns to research!andrew