Reversing a file?

[Steven M. List]

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

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 :                Steven List @ Transact Software, Inc. :^>~                  :
 :           Chairman, Unify User Group of Northern California                :
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