Linux commands

In this subsection, let's open the command line and execute some basic commands. In every Linux host, there are command-line interfaces named shells that interpret and execute typed commands and scripts. There are many shell environments, such as Bourne Again Shell (Bash, which is the most common shell), C shell (csh), Korn shell (ksh), and so on. To find the shells available for your environment, just open the command-line interface and type cat /etc/shells:

Now, let's get around some vital basic Linux commands from the shell:

• pwd: To know which directory you are in
• ls: To list files in a directory
• cd: To enter a directory
• mkdir: To create a new directory
• rmdir: To remove a directory
• touch: To create a new file
• cat: To read a file
• cp: To copy a file
• mv: To move a file
• man: To be shown how to use a command

As a penetration tester, there are multiple important commands that you need to know in order to test the security posture of a Linux infrastructure:

• hostname: Information about the host
• cat /proc/version: Kernel information
• uname -r: Kernel release
• uname -a: More detailed information about the system
• cat /proc/cpuinfo: Reads information about the processor
• echo $PATH: Display information about the PATH variable
• history: Display command history