Comments on: Fun with Linux Commands-I

By: Linux

Linux — Tue, 21 Oct 2008 13:08:56 +0000

iotop, iostat, vmstat etc…

By: Zartan

Zartan — Mon, 20 Oct 2008 20:18:53 +0000

Most shells that support “cd -” will also support “~-” in pathname expansions. The ~- construct expands to the previous working directory, so “cd ~-” is the same as “cd -”.

This is useful in a number of situations. Suppose you want to unpack a tarball that you’ve just downloaded and filed away in your new releases archive part of the file tree. You are in the directory where you stored the tarball and want to unpack it in /tmp to look it over. Just do:

cd /tmp
tar -xzvf ~-/some_software-version.tgz

Generally ~- (or ~-/) will be expanded by TAB (or ESC-\ if in vi mode), so for the previous example you only need type a few characters of the filename and a TAB.

By: Daniel

Daniel — Mon, 20 Oct 2008 15:52:44 +0000

To correct the earlier responder, the expansion for the last word of the last command is “!$”. This is dual to “!^”, for the first word of the last command. And a third, very useful expansion is “!*”, for all the parameters to the last command. For instance, if you just entered a long command line beginning with “apt-gte”:

apt-gte install foo foo1 foo2 foo3 …

you can run “apt-get !*” to correct the mistake.

By: Bender

Bender — Mon, 20 Oct 2008 14:58:04 +0000

“rm -rf ~” is fun too ! (DON’T TRY THIS !!!!!!!!!!!!!!! THIS WILL ERASE ALL YOUR HOME DIRECTORY)

I like command like this one :

cat video.avi | ssh user@server xine – or to backup your user account :

cd;tar zcvf – *| ssh user@backup_server dd of=backup.tar.gz

By: Dan Haworth

Dan Haworth — Mon, 20 Oct 2008 14:45:45 +0000

In my 11 years of linux use, i’ve never come across cd -

Thanks very much!

By: A

Mon, 20 Oct 2008 11:23:58 +0000

Bash history variables do not work in shell scripts.

By: Arkay

Arkay — Mon, 20 Oct 2008 10:16:25 +0000

I’m assuming “saytime” is included in ubunutu. It sure as hell isn’t on my install of Arch.

Perhaps it might be a good idea to specify that the command line arguments you’re supplying work with distro “X”.

As saytime, while a nice gimmick, is not all that useful as a terminal command and consequently may not be included on all that many distros…

Ubuntu is not the ONLY Linux…

Cheers,

Arkay.

By: Planet Malaysia

Planet Malaysia — Mon, 20 Oct 2008 09:43:50 +0000

saytime is NOT available on my Redhat, VMware ESX & SuSE box by default.

By: Robert de Bock

Robert de Bock — Mon, 20 Oct 2008 07:31:41 +0000

$ !! is a great one, here is another cool one to repeat only the last argument of the previous command:

$ ls this-complex-file-name.txt

$ ls -l $!

Regards, Robert de Bock.

By: adamkasza

adamkasza — Mon, 20 Oct 2008 07:27:05 +0000

Recently I was astonished by the command line tools provided by the ImageMagick suite (www.imagemagick.org) for manipulating images.

You can convert between file formats and resize images with it by executing a single command. For instance, to resize a JPEG image to 800 px wide (keeping aspect ratio) and to save it in PNG you have to execute this:

$> convert test.jpg -filter Lanczos -resize 800 test.png

And you can do a lot more with it…

I also loved jhead (http://www.sentex.net/~mwandel/jhead/). If you have a digital camera that writes the orientation into the EXIF data, then you can rotate all images automatically:

$> jhead -autorot ./*