[ILUG] new grep

[Brian Foster]

#
  | Date: Mon, 25 Mar 2002 17:05:39 +0000
  | From: Padraig Brady <padraig at antefacto.com>
  |[ ... ]
  |  sed -n -e "/[0-9]/p" testfile
  | 
  | is the same as:
  | 
  |  grep "[0-9]" testfile

 and:

   ed testfile
   g/[0-9]/p
   q

 is a superset of both; ergo, by this logic,
 _both_ grep and sed are superfluous.

 superset because, e.g., ed can "go backwards"
 in a file, whilst neither sed nor grep can.
 hence, as an example, the previous challenge
 of `grep -C5 re file' can be done as:

   ed file
   g/re/.-5,.+5p
   q

 however, if you've ever tried to use ed in
 a pipeline (e.g.), you'll probably quickly
 appreciate why sed came to be.

 as noted previously, both sed and grep were
 originally derived from the more general ed.
 so the argument seems to be they "shouldn't"
 have been derived --- or even necessary? ---
 in the first place.  that seems to be an
 unsupportable proposition, as it appears
 to deny that specialist tools (e.g. hammers)
 are needed when a general solution can be
 used (e.g. rocks).

  |[ ... ]
  | I think it's as easy for someone to learn the p command
  | in sed, as a seperate grep command. That just takes a
  | minute or two.  [ ... ]

<IMHO>
 whilst I question the example stated, there
 is a similar example along those lines which
 seems to have some validity:

   head -20 file

 is the same as:

   sed 20q file

 the "ease of typing" argument doesn't apply to
 this example; and the "overhead" counter-argument
 is problematic.
</IMHO>

cheers!
	-blf-
--
 Innovative, very experienced, Unix and      | Brian Foster    Dublin, Ireland
 Chorus (embedded RTOS) kernel internals     | e-mail: blf at utvinternet.ie
 expert looking for a new position ...       | mobile: (+353 or 0)86 854 9268
  For a resume, contact me, or see my website  http://www.blf.utvinternet.ie