Unix Tip #4408- April 6, 2014


SEARCH : Home : Help : Today's Tip

ENHANCED #1576 FILE REVERSAL


This is an enhancement to
UNIX Tip #1576 - April 25, 2001.

The original tip is kind a
cool, so I decided to enhance it.

I hope it's okay with the main author.

#!/bin/ksh
lns=`wc -l $1 | nawk '{ print $1 }`
{
cat $1 | awk '{ line[NR] = $0; }
{ for (i = NR; i > 0; --i) print line[i] }'
} >> $$.temp
tail -"$lns" $$.temp
rm $$.temp

This tip generously supported by: jena_m@hotmail.com

---------------------------------------

FILE REVERSAL

For those that don't have
the tac command, to reverse
a file in UNIX, you could use:

cat | awk '{ line[NR] = $0;} END
{for(i=NR;i>1;i--) print line[i] }'


This tip generously supported by: chandramohan_k@infy.com


NOTE: All tips provided are USE AT YOUR OWN RISK. Tips are submitted by various unix admins around the globe. UGU suggest you read and test each tip in a non-volitile environment before placing into production.


LAST 5 TIPS
4407 - READ IN THE OUTPUT
4406 - FTP AUTOMATED TRANSFERS
4405 - VIEWING ALL C FILES AT ONCE
4404 - ANOTHER RENAMING UPPER TO LOWER
4403 - RESTARTING PROCESSES


I want to SUBSCRIBE and get a UGU Tip everyday.
I want to UNSUBSCRIBE and NOT get a UGU Tip everyday.

If you have a UNIX TIP let us know, we just may use it:
(All tips become the property of the Unix Guru Universe)
Email Address:

Yes, email me a Hot Unix Tip everday.

Enter Hot Unix Tip (optional):

Yes, I will support this tip

Captcha (not case sensitive):


Please enter the above letters:


HOME | Flavors | Admin | Network | Security | S/W | Help | Events | Vendors | Careers | Internet
About | Add Link | Feedback | Search

Copyright © 1994-2005 Unix Guru Universe