Why Different Commands ?

[Toby Kelsey]

Vilas Sukhadeve wrote:

> Here I would like to know why different commands have to be used in
> Terminal. e.g. sudo, apt-get, chmod, mkdir, #, I know only these
> commands so far. What these different commands stand for ? If you feel
> this is just child like query but still as a responsible parent please
> tell me just for my information.

Many command names are abbreviations of the description, thus

sudo  = superuser-do
mkdir = make a directory
pwd   = print working directory
chmod = change file mode

Note: 'directory' means 'folder'.
This makes it a bit easier to remember the name of the command.  Ubuntu Terminal
commands are a version of what is called the Unix command-line, so if you google
"unix command-line tutorial" you will find some helpful documents.

Some common commands are:
ls, pwd, cd, less, grep, file, bash, locate, find, sudo, ps, kill, top, rename, 
mv, rm, mkdir, sed, sleep, date, apropos, du. df

To find out what a command does, use the 'man' or 'info' command.
For example,

   man ls

or

   info ls

will tell you about the command 'ls'.  To find out which command does a
particular thing, try

   apropos [thing]

The Terminal commands are processed by 'bash', so to find out what else the 
terminal can do apart from just running a single command, type

   man bash

Have fun,
Toby