The Linux File-system
The directories you will find most useful are:
• /bin - basic programs (ls, cd, cat, etc.)
• /sbin - system programs (fdisk, mkfs, sysctl, etc)
• /etc - configuration files
• /tmp - temporary files (typically deleted on boot)
• /usr/bin - applications (apt, ncat, nmap, etc.)
• /usr/share - application support and data files
Basic Linux Commands
MAN - Most executable programs intended for the Linux command line provide a formal piece of
documentation often called manual or man pages
Examples
kali@kali:~$ man ls
kali@kali:~$ man passwd
kali@kali:~$ man -k passwd #if we use the -k option with man, we can perform a keyword search as shown below
kali@kali:~$ man -k '^passwd$' #We can further narrow the search with the help of a regular expression
apropos - With the apropos command, we can search the list of man page descriptions for a possible match based on a keyword
kali@kali:~$ apropos passwd #Note that apropos seems to perform the same function as man -k
Listing Files - The ls command prints out a basic file listing to the screen
kali@kali:~$ ls
kali@kali:~$ ls -al
Moving Around - We can use the cd command followed by a path to change to the specified directory.The pwd command will print the current directory
kali@kali:~$ pwd
kali@kali:~$ cd /usr/share/
Creating Directories - The mkdir command followed by the name of a directory creates the specified directory.We can create multiple directories at once with the incredibly useful mkdir -p, which will also create any required parent directories.
kali@kali:~$ mkdir sysnet #creates a directory called sysnet
kali@kali:~$ mkdir -p test/{recon,exploit,report}
kali@kali:~$ ls -1 test/
exploit
recon
report
Finding Files in Kali Linux -
which - The which command39 searches through the directories that are defined in the $PATH environment variable for a given file name.
kali@kali:~$ which sbd
/usr/bin/sbd
locate - The locate command40 is the quickest way to find the locations of files and directories in Kali.
kali@kali:~$ sudo updatedb #To manually update the locate.db database, you can use the updatedb command
kali@kali:~$ locate sbd.exe
find - The find command41 is the most complex and flexible search tool among the three
kali@kali:~$ sudo find / -name sbd*
Enable Services in Kali Linux
SSH Services
kali@kali:~$ sudo systemctl start ssh #To start SSH Services
kali@kali:~$ sudo ss -antlp | grep sshd #To verify SSH Service
kali@kali:~$ sudo systemctl enable ssh #Enable SSH at boot
HTTP Service
kali@kali:~$ sudo systemctl start apache2 #To start HTTP Services
kali@kali:~$ sudo ss -antlp | grep apache #To verify HTTP Service
kali@kali:~$ sudo systemctl enable apache2 #Enable HTTP at boot
Note :
To see a table of all available services, run systemctl with the list-unitfiles option:
kali@kali:~$ systemctl list-unit-files
We can use systemctl to enable and disable most services within Kali Linux.
Searching, Installing, and Removing Tools
apt update - Information regarding APT packages is cached locally to speed up any sort of operation that involves querying the APT database. Therefore, it is always good practice to update the list of available packages, including information related to their versions, descriptions, etc
kali@kali:~$ sudo apt update
apt upgrade - we can upgrade the installed packages and core system to the latest versions using the apt upgrade command.
kali@kali:~$ apt-cache search pure-ftpd #The apt-cache search command displays much of the information stored in the internal cached package database
kali@kali:~$ apt show resource-agents
apt install - The apt install command can be used to add a package to the system with apt install followed by the package name
kali@kali:~$ sudo apt install pure-ftpd
apt remove --purge -The apt remove –purge command completely removes packages from Kali
kali@kali:~$ sudo apt remove --purge pure-ftpd # we can remove a package with the command apt remove --purge
dpkg
kali@kali:~$ sudo dpkg -i man-db_2.7.0.2-5_amd64.deb #dpkg is the core tool used to install a package, either directly or indirectly through APT.
