Comments on: Four Completely Useless Linux Commands

By: Kevin Frank

Kevin Frank — Fri, 03 Jun 2011 20:21:00 +0000

I agree. These commands are useless. Here is a useless application of yes.

touch junk1 junk2 junk3
chmod -w junk*
rm junk*
“nothing happens”
yes | rm junk*
“junk files are removed”

Regards,
Kevin

By: cras

cras — Mon, 16 May 2011 11:51:54 +0000

yes is insanely useful, and I use it every day for rm -r dir/with/lots/of/children/ | yes as I have confirmation aliased in.

As said before, rev is handy for getting the last character/line and in scripts in general.

ul is really just a curiousity nowadays, but is used for typesetting (presumably in man pages and the like). If you don’t know what troff is then you will never need it

vdir is usually an alias for “ls -la”, and is one character shorter (or two characters longer if it’s in your .bashrc). Again, a bit of a curiosity.

By: VIKAS

VIKAS — Tue, 13 Apr 2010 07:28:35 +0000

“yes” commands is definitely useful.

It can be used to run infinite loops without using crontab

For e.g.
yes “date;sleep 1″ | sh

By: abhishek

abhishek — Thu, 22 Oct 2009 12:30:30 +0000

yes can be used to generate very large files for simple testing of some filer applications or wherever you need to generate a garbage big file.

yes abhishek > testfile

By: Nanjundi

Nanjundi — Thu, 19 Feb 2009 17:09:05 +0000

Ziemowit Pierzycki,
s/xarg/awk/

By: manas

manas — Thu, 19 Feb 2009 08:21:09 +0000

I never use “clear” command. Whats the point of it? I can always clear my terminal using Ctrl+L.

By: tony

tony — Thu, 19 Feb 2009 00:24:59 +0000

vdir (4 chars)
ls -lb (6 chars)

You would type less whenever you can in *nix world.

By: David Gray

David Gray — Wed, 18 Feb 2009 20:06:13 +0000

Actually the colon (null command) is quite useful [see Feb 3 comment].

Say you have a script with lines that might be enabled later (as in a skeleton for installation). Since If/then/elif/fi won’t work with nothing in its clauses one can do the following.
if [[ $self == intall* ]] then :
# install_it
elif [[ $self == backout* ]] then :
# unistall_it
fi
One need not bother removing the colon when lines are uncommented.

Another use is when you only need a side effect. If the variable “self” has not already been set, the code below will concisely assign it to the invoking script’s name with any path data stripped off.
: ${self:=${0##*/}}

By: John Dudeck

John Dudeck — Wed, 18 Feb 2009 16:22:55 +0000

I wrote an equivalent of ‘rev’ for dos. I use it to reverse the order of a list of domains or email addresses, then I sort them, then reverse them back. This gives me a list that is grouped together by domain name.

By: hariharasubramanian

hariharasubramanian — Mon, 09 Feb 2009 04:21:22 +0000

In some other cases ( for the user development) the rev command can be used. Also if we want to encrypt the data and sent it to some other place, we can use rev command. (It’s low level security encryption).

Also if we want to get the last character of the file in each line, we can use this command. According to the user need, we can use the command.