Basic Command Search on Linux/Unix Environment

Basic Command Reference on a Linux / Unix Environment is easy. On a blog posting name 'Thoughtful Thoughts' I found this post is related to Basic Command Reference Search.

The author found his classmate including other people are looking for Linux command by asking question like:

“is there any command in linux”
“what is the command in linux”
“how can I be familier with linux”
“I want to start learning linux”

He suggest to format their question in following way, like:

I can tell some basic things to solve problems in *nux/*nix environment.
suppose I want to do a “stuff” say [stuff]
[stuff] may be play Freecell,
format drive, mount drive, filter packet, see available ports in use, blah blah blah …
try using google like this,

how to [stuff]
I want to [stuff]
way to [stuff]

Yes, Google is great way to find reference online. But what if you don't have access to Internet yet? This is unforchanet but true. A lot of people still don't have access to Internet for full time. On this case I would encourage you to use the 'tab' button on your keyboard. Yes this is a very easy way to find command on Linux / Unix Environment.

If you are using a command line, the 'tab' key on your keyboard can help you to find the actual command (Most of modern command terminal support tab key). Say you are looking for change your password, what would be the command?

Try writing 'pas' and press your tab key twice, like bellow:

yourbox@you~$pas [tab tab]

It will show you ALL command start with keyword 'pass', you will see a list of command available on your box like bellow:

yourbox@you~$pass
passmass passwd
yourbox@you~$pass

Now you can see the password changing command is 'passwd'. You can make sure by getting information of command using '-h or --help' operator.

yourbox@you~$passwd --help

Usage: passwd [OPTION...]
-k, --keep-tokens keep non-expired authentication tokens
-d, --delete delete the password for the named account (root only)
-l, --lock lock the named account (root only)
-u, --unlock unlock the named account (root only)
-f, --force force operation

-x, --maximum=DAYS maximum password lifetime (root only)
-n, --minimum=DAYS minimum password lifetime (root only)
-w, --warning=DAYS number of days warning users receives before
password expiration (root only)
-i, --inactive=DAYS number of days after password expiration when an
account becomes disabled (root only)
-S, --status report password status on the named account (root
only)
--stdin read new tokens from stdin (root only)

Help options:
-?, --help Show this help message
--usage Display brief usage message

yourbox@you~$passwd --help

See this Linux Command Reference for a list of available standard Linux / Unix Command.