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From: merlyn@iwarp.intel.com (Randal Schwartz)
Newsgroups: comp.unix.questions
Subject: Re: Reversing a file?
Message-ID: <5019@omepd.UUCP>
Date: 6 Oct 89 15:28:46 GMT
References: <MONTNARO.89Oct2224215@sprite.crd.ge.com> <1989Oct3.201759.19182@mrspoc.Transact.COM>
Sender: news@omepd.UUCP
Reply-To: merlyn@iwarp.intel.com (Randal Schwartz)
Organization: Stonehenge; netaccess via Intel, Hillsboro, Oregon, USA
Lines: 37
In-reply-to: itkin@mrspoc.Transact.COM (Steven M. List)

In article <1989Oct3.201759.19182@mrspoc.Transact.COM>, itkin@mrspoc (Steven M. List) writes:
| montnaro@sprite.crd.ge.com (Skip Montanaro) writes:
| 
| >Does somebody have an elegant shell script for reversing the lines of a
| >file? I've come up with the following short one:
| 
| This uses one of my all-time favorite VI/EX commands, and this is the
| first time I can remember anyone ASKING for it:
| 
| 	echo "g/./.m0\nw $OUTPUT\nq" | ex $INPUT
| 
| the "g/./.m0" marks every line in the file and then moves each marked
| line to the beginning of the file (after line zero).  The "w $OUTPUT"
| will either write the reversed file to a new file or overwrite the
| original file, depending on whether or not OUTPUT is valued.
| 
| For those of us who DON'T have "tail -r", this works great!  From within
| VI, you can use the same global command:
| 
| 	:g/./.m0
| 

Arrgh.  Both of those fail on *blank* lines.  (They'll all end up at
either the beginning or the end... I'm too tired to figure out which.)

Try:

   echo "g/^/m0|w $OUTPUT|q" | ex $INPUT

instead.

Just another 'ex' hacker,
-- 
/== Randal L. Schwartz, Stonehenge Consulting Services (503)777-0095 ====\
| on contract to Intel's iWarp project, Hillsboro, Oregon, USA, Sol III  |
| merlyn@iwarp.intel.com ...!uunet!iwarp.intel.com!merlyn	         |
\== Cute Quote: "Welcome to Oregon... Home of the California Raisins!" ==/