Black Hat Bash - Bash Scripting for Hackers and Pentesters (Early Access) (Dolev Farhi, Nick Aleks)

$ ls -la

$ ls -l -a

Note that some commands may throw errors if you attempt to

join two arguments using a single dash, so use the man command to

learn what syntax is permitted.

Some command options may allow you to use long-form

argument syntax, such as the --help command to list the available

options. Long-form argument syntax is prepended by the double

dash (--) symbol:

$ ls --help

Sometimes, the same command argument supports both short-

and long-form argument syntax for convenience. For example, ls

supports the argument -a (all) to display all files including those

that are hidden (files starting with a dot in their name are considered

hidden files in Linux), but you could also pass the argument --all,

and the outcome would be identical.

$ ls -a

$ ls --all

Let’s execute some simple Linux commands so you can see the

variation of options each offers. First, create a single directory with

mkdir:

$ mkdir directory1

Now let’s create two directories with mkdir:

$ mkdir directory directory2

Next, list processes with ps using short-hand argument syntax,

supplying the arguments separately and then together:

$ ps -e -f

$ ps -ef

Lastly, let’s display the available disk space with df using long-

form argument syntax:

$ df --human-readable

Later in this book, you’ll write your own scripts that can take

various arguments.