Origin of the name grep - (nf)

[sarwate at uicsl.UUCP]

#R:pegasus:-164100:uicsl:11300001:000:259
uicsl!sarwate    Aug 27 11:44:00 1984

grep stands for g/re/p which is an ed command to print all lines matching
the thing within the /'s.  re means regular expression in this context.

Reference: B. W. Kernighan, "Advanced Editing on UNIX", p. 15, in
UNIX Programmer's Manual, vol. 2A, Jan. 1979.