Bash Command Quick Reference

 Bash Command Quick Reference

ls => list of files in a folder / directory 

$ ls

 

List of files with permission (long format)

$ ls -l 

List of all files in a directory

$ ls -a 

cd => change directory

$ cd <folder>

Go back to home

$ cd 

Or 

$ cd ~

Create or make a directory or folder

$ mkdir Junk

Locate or search a file.

$ locate filename

To update system db

$ sudo updatedb

"Which" command is used to find other commands

$ which cal

(cal represents calendar command)

Use "history" command to display the history of all the commands you used

$ history

To know what the command does (use whatis command)

$ whatis cal

Copy a file use cp command (cp sourcefile newfile)

$ cp ~/.bashrc bashrc

Move a file (this overwrites and deletes the source file)

$ mv sourcefile targetfile.bash

Remove a file (rm command)

Cat command - "cat" command is used to read the file and display in the monitor

$ cat file1 file2

(merge file1 and file 2 content and shows in the screen)

$ cat >> file2

Append text

$ cat > file3 

(new file)

$cat 

Nano => 

$ nano

Copy the list of files and access from root directory and write it to a file called out.txt

$ ls -al / > out.txt

To see the output of a file used below command

$ less out.txt

Sudo => if we need to run a command with elevated privileges / access.

$ sudo updatedb

$ sudo -s

Exit

$ su - cindy

(This command will switch user to cindy and do necessary work)

$ exit

logout

This appends the output to all.txt

cat *.txt >> all.txt

This overwrites all.txt

cat *.txt > all.txt

Kill a process or application

$ killall firefox