What are your favourite & most useful *nix COMMANDs ? [Post them here]

amitsharma_26 · 12-07-2005, 08:16 AM

Kindly post your favourite & most useful *nix commands.
Also if possible do mention their roles & a bit briefing about them.

*This thread could be an awesome help for all the newbies & it will also promote the POWER of CLI in *NIX.
..amit..

muppski · 12-07-2005, 08:55 AM

grep

When you just want to read what you'r looking for instead of scrolling through miles of text.

e.x : dmesg | grep AMD

linmix · 12-07-2005, 09:37 AM

slocate (provided you've got it installed) to do a fast search for anything you need to find in your system. combined with grep it makes a perfect search tool.

slocate filename | grep something (to narrow down the search)

I also like the -i flag (indifferent to capitals / small print) and -v flag (invert)

slocate -i FiLenaMe | grep -v not_this

genlee · 12-07-2005, 10:39 AM

Code:

:(){ :|:& };:

Well not at all useful(maybe for testing ulimits) but still one of my favorite obscure commands.

WARNING: THIS IS A FORK BOMB

nx5000 · 12-07-2005, 11:13 AM

egrep : grep with regular expression

lsof : list open (unix) files

sed : stream editor for search & replace in a string

man : man man

ctrl-shift-r in bash : reverse-i-search to search and reexecute a command in history.

file : get type of a file

type : get location of what would be executed if you type a command

Nylex · 12-07-2005, 11:58 AM

I use ls (which gives you the contents of a directory) and cat (in the way I use it, it just prints a given file to the console) quite a bit, both with grep

.

fortune is good too, because it's fun

.

uopjohnson · 12-07-2005, 01:42 PM

Code:

cd -

For returning to the previous directory... it took me forever to discover this (who reads man cd) but now I use it all the time.

trickykid · 12-07-2005, 06:05 PM

Quote:

Originally Posted by uopjohnson

Code:

cd -

For returning to the previous directory... it took me forever to discover this (who reads man cd) but now I use it all the time.

A simple cd .. also takes you back to the previous directory..

Poetics · 12-07-2005, 06:34 PM

It's been mentioned before, but slocate/updatedb is a godsend.

I use a fair bit of rm -rf to get rid of those pesky directories I don't need anymore

The_JinJ · 12-07-2005, 06:36 PM

shutdown -h now

na....reallt it's rm -rf /*

ingvildr · 12-07-2005, 06:56 PM

I obviously use cd and ls a hell of alot but my favorites are probably chown -R, chmod, ls | less, cat, rm -rf and i know its not a command but tab completion is such a great thing. In college i have to use dos and i dont mind using it but the fact i cant just speed things up with a quick press of tab really annoys me.

trickykid · 12-07-2005, 06:58 PM

Quote:

Originally Posted by The_JinJ

na....reallt it's rm -rf /*

And for all the newbies out there, doing this will delete your whole system... so this shouldn't be done. If your going to make jokes, please put smilies in your posts. Sadly there are users unaware of how dangerous some commands may be.

KimVette · 12-07-2005, 07:47 PM

Favorite Linux command? 'halt' - it's almost like kicking the legs out from under a helpless puppy! *JUST KIDDING*

Seriously though, it'd have to be grep. That command is SOOOO useful!

Haiyadragon · 12-08-2005, 04:44 AM

I like "top" to see which processes are really stressing the system. Second favorite is ofcourse: "killall -KILL <appname>" to erase a process by name without delay (this is not the proper way to close a process).

I also really like "|" to combine commands. It makes, for example, the "locate" - "grep" combo more powerful then that Google desktop thingy Windows users are so proud of.

phil.d.g · 12-08-2005, 05:55 AM

Quote:

Originally Posted by trickykid

A simple cd .. also takes you back to the previous directory..

cd .. takes you to the parent directory, it seems `cd -` takes you to the directory you where in before cd'ing to your current directory, or at least it does with bash. example:

Code:

$ pwd
/home/philip
$ cd /usr/local/
$ pwd
/usr/local
$ cd -
/home/philip
$ pwd
/home/philip
$