As a tech, you’ll no doubt come in contact with Linux. This post has a few basic Linux commands you should know.
If you want more information on various commands you can enter man <command>.
Table of Contents
Basic Usage
| Command | Function | Example Usage |
|---|---|---|
| man | view manual entry | man mount |
| ls | list directory content | ls /home/user |
| mkdir | make directory | mkdir /home/user/new |
| rmdir | remove directory | rmdir /home/user/deleteme |
| cd | change current directory | cd /home/user/new |
| pwd | print current directory | pwd |
| rm | remove (delete) file | rm todelete |
| cat | output file to std out (screen) | cat /home/user/file.txt |
| grep | regex search | grep strtofind /home/user/file.txt (see man page); use grep -i for case insensitive |
| tail | output last lines of file | cat /home/user/log.txt | tail |
| more | by-page view of file | cat /home/user/log.txt | more |
| dmesg | prints message buffer of kernel | dmesg | more |
| top | display process information | top |
| mv | moves the specified files | mv -i originalfile newfile |
| cp | copies the specified files | cp -R sourcedestination |
Basic Diagnostics
| Command | Function | Example Usage |
|---|---|---|
| lspci | list PCI devices | lspci -v |
| lsusb | list USB devices | lsusb -v |
| df -h | display free space on disks | df -h |
| sudo fdisk -l | list connected devices | sudo fdisk -l |
| tail -f | watch a log live | tail -f /var/log/messages |
Basic Networking and Processing
| Command | Function |
|---|---|
| ifconfig -a | show net adapter information |
| ifconfig -a | grep HWaddr | print MAC addresses |
| ps -A | grep <program name> | kill processes by name |
| sudo /etc/init.d/networking restart | restart networking |
| sudo /etc/init.d/gdm restart | restart graphics system (gnome) |
| sudo dexconf | reset graphics configuration |
| sudo ufw status | get firewall status |
| sudo ufw enable | turn on the firewall |
| ufw allow port | allow port |
| ufw deny port | block port |
| sudo apt-get -f install | try to fix broken packages |
| sudo apt-get upgrade | upgrade all packages |
