what should egrep '|root' /etc/passwd print?

[Barry Shein]

Just to add some history to the discussion:

>From "The SNOBOL4 Programming Language", Griswold et al, Section 2.6
pp. 35:

"2.6 The Null String in Pattern Matching

The null string is the string of zero length. Attempts by the scanner
to match the null string always succeed...Pattern matching in the
statement

	STR NULL			:S(ON)F(ERROR)

always succeeds, even if STR itself has the null string as value."

Perhaps the SNOBOL crew could be consulted for their original
reasoning. I suspect there is a reasonable set-theoretic argument
which can be made (e.g. the null set is the subset of all other sets.)

	-Barry Shein, ||Encore||