Techie June 2022
1 . Navigate back to a previous directory.
$ cd -
2 . Navigate to the home directory
$ cd ~
or:
$ cd
3 . Clear the terminal
$ clear
or:
CTRL + L
4 . Reset the shell
Clears the screen and removes the history, so you cant scroll back.
$ reset
5 . Remember a directory and navigate back to it later.
$ pushd /some_directory # remembers the directory
$ popd # navigates back to that directory
6 . Minimize a command line program to the background.
NB: Dont close the shell since that will terminate the program
CTRL + Z
bring it back:
$ fg # for foreground
7 . Execute a command that was last executed.
$ !!
You can prepend another command to it:
$ sudo !!
8 . Search Command History
CTRL + R
Then type the key words you wish to search for and press enter when you find the command or use CTRL + R to scroll through the matching results.
9 . Show command history.
$ history
Run a command from the history list:
$ !command_number
e.g
$ !985
10 . Include the date and time on the history command
Temporarily on the current shell session:
$ HISTTIMEFORMAT="%Y-%m-%d %T " #deliberately add the space at the end for readability
Set the variable permanently:
Open .bashrc file and add the variable on it
$ nano ~/.bashrc
Add this:
HISTTIMEFORMAT="%Y-%m-%d %T "
11 . Adjust font size
CTRL + + # increase font size
or:
CTRL + - # decrease font size
12 . Backspace everything out
NB: Also clears the command from the history
CTRL + U
13 . Move the cursor to the begining of a line
CTRL + A
14 . Move the cursor to the end of a line
CTRL + E
15 . Chain commands
$ command_1; command_2
e.g
$ mkdir ~/example; cd ~/example
Alternatively:
NB: With this method, If the first command fails, subsequent commands won’t be executed.
$ command_1 && command_2
e.g
$ mkdir ~/example && cd ~/example
16 . List everything in current directory
$ ls
17 . List everything in current directory including hidden files
$ ls -a
18 . List everything in current directory in a long list format showing file attributes
$ ls -l
19 . List everything in current directory in a long list format showing file attributes and size in readable format
$ ls -lh
20 . Tail log files
$ tail -f file_name
e.g
$ tail -f production.log
21 . Tail log files more efficiently
NB: less +F reads the whole file, whereas tail -f only reads the end of the file.
$ less +F file_name
To view the whole file, detach with:
CTRL + C
Re-attach with:
SHIFT + F
Press q to exit
less +F is impractical for very large files. You can, however, run less -n +F, which causes less to read only the end of the file, at the cost of not displaying line numbers.
You can make it truncate lines at the screen width with the -S option, whereas tail gives you no choice but to display the whole line no matter how long it is.
22 . Errase file contents without deleting the file
$ truncate -s 0 file_name
23 . Pipe a command’s output into the column command to make the results readable
$ command_1 | column -t
e.g
$ mount | column -t
24 . Cut the line of text from the cursor point to the end
CTRL + K
Undo the the cut:
CTRL + Y
25 . Cut the line of text from the cursor point to the begining
CTRL + U
Undo the the cut:
CTRL + Y
26 . Cut words backwords
CTRL + W
Undo the the cut:
CTRL + Y
27 . Use a file editor to write long commands or script-like commands
NB: Set micro, vim etc as your default text editor, since nano is not suitable for this task
CTRL + X + E
28 . Scroll through previous arguments in history
ALT + .
29 . Print the path of the working directory
$ pwd
30 . Create a directory
$ mkdir directory_name
31 . Navigate into a directory
$ cd directory_name
32 . Navigate one level out of a directory
$ cd ..
33 . Navigate to the root directory
$ cd /
34 . Create a file
$ touch file_name.extension
e.g
$ touch example.txt
35 . Show file content
$ cat file_name
36 . Rename a file
$ mv original_file new_file
e.g
$ mv file1.txt file2.txt
37 . Copy a file
$ cp original_file copy_file
38 . Compress a file
$ zip zipped_file_name.zip file_name
39 . Decompress a file
$ unzip zipped_file_name.zip
40 . Delete a file
$ rm file_name
41 . Delete a directory
$ rmdir directory_name # only deletes empty directories
or:
$ rm -r directory_name
42 . Find file location
$ which file_name
43 . Show current user’s name
$ whoami
44 . Show network information
$ ifconfig
For wireless info:
$ iwconfig
45 . Find a directory by name
$ find location_path -type d -name "directory_name"
e.g $ find / -type d -name “dendrite”
46 . Check server status
$ systemctl status server_name
e.g
$ systemctl status jellyfin
47 . Find information like version number(If not possible with normal method):
$ dpkg --list | grep file_name
e.g
$ dpkg --list | grep plex
48 . Check the system information
$ uname -a
49 . Display information about available drives.
$ blkid
50 . Show a real-time view of running processes
$ top
51 . Display the disk space used in the file system
$ df
52 . Display the information about USB buses and the devices connected to them
$ lsusb
53 . Running a process in the background
Continue to run processes after exiting the terminal
$ nohup command_name &
NB: You must note down the ID. You will need it to kill the process.
Incase you lose the process id:
Find the process by name
$ ps -ef | grep "name_of_process"
e.g
$ ps -ef | grep "jekyll"
Kill the process by PID
$ kill id_here
or:
Bring the process to the foreground and then CTRL + C
$ fg
54 . Install app from package manager
$ sudo apt-get install app_name
55 . Uninstall app
$ sudo apt-get remove app_name
56 . Update packages
$ sudo apt-get update
57 . List files with specific extension
$ ls *.extension
e.g
ls *.txt
58 . Search words in files
$ grep -i -R 'the_word' search_path
e.g
$ grep -i -R 'users' /home/Desktop
59 . Restart machine
$ sudo shutdown -r
or:
$ sudo reboot
60 . Shutdown machine
$ sudo shutdown -h now
Shutdown machine after a specific period of time
$ sudo shutdown -h 10
# Do this to cancel
$ shutdown -c
or:
$ sudo shutdown -P +10
Thanks for reading, see you in the next one!
