Reversing a file?

[Randal Schwartz]

In article <1989Oct3.201759.19182 at mrspoc.Transact.COM>, itkin at mrspoc (Steven M. List) writes:
| montnaro at 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 at iwarp.intel.com ...!uunet!iwarp.intel.com!merlyn	         |
\== Cute Quote: "Welcome to Oregon... Home of the California Raisins!" ==/