b5media.com

Advertise with us

Enjoying this blog? Check out the rest of the Technology Channel Subscribe to this Feed

New Linux User

HOWTO: Use the TAC Command.

by Jon on April 13th, 2006

I’m sure you’re all just absolutely thrilled that I’m studying for my LPIC. Otherwise, you wouldn’t have all thes neato posts about obscure Linux commands that you’ll likely never use.

Ah well. Let me get over this first chapter and then we’ll get into the more interesting stuff:)

Today’s command is tac. The tac command is named purposely as a reverse of the cat command because, well, it prints out files in reverse. If I have a file named animals that looks like:

The dog
The cat
The bird

and I run the command tac animals, I get:

The bird
The cat
The dog

There are a few switches you can tack (get it?!) onto the end to modify the default behaviour.

Useful? Now and again, I suppose.

POSTED IN: General

1 opinion for HOWTO: Use the TAC Command.

  • jadu saikia
    Nov 2, 2008 at 9:14 am

    tac is useful for reversing order of all lines of a file. I feel tac needs to provide ways to reverse order of few lines(not all lines); e.g.

    $ cat details.txt
    line1
    line2
    line3
    line4
    line5
    line6
    line7
    line8
    line9
    line10

    reverse order of lines from 5 to 8

    line1
    line2
    line3
    line4
    line8
    line7
    line6
    line5
    line9
    line10

    We can achieve this using awk; but a support from tac would have been more handy.

    // unstableme.blogspot.com

Have an opinion? Leave a comment:




Check Spelling
Activate Spell Check while Typing