Bash Scripting Cheat Sheet

Bash scripting is a powerful tool that allows users to automate tasks and perform complex operations on their computer systems. Bash is a command-line shell that is widely used in Linux and Unix-based operating systems. It provides a powerful set of tools for managing files, running programs, and manipulating data.

Bash scripts are essentially a series of commands that are executed in sequence. They can be used to automate repetitive tasks, such as backing up files or running system maintenance tasks. They can also be used to perform complex operations, such as parsing data or manipulating files.

This cheat sheet provides an extensive list of commands and syntax used in Bash scripting. Enjoy!

Basic Commands

Command	Description
echo	Prints text to the terminal
cd	Changes the current directory
ls	Lists the contents of a directory
pwd	Prints the current working directory
mkdir	Creates a new directory
touch	Creates a new file
rm	Removes a file or directory
cp	Copies a file or directory
mv	Moves a file or directory
cat	Concatenates and displays files
grep	Searches for a pattern in a file
chmod	Changes the permissions of a file or directory
chown	Changes the owner of a file or directory
sudo	Executes a command with superuser privileges

Variables

Syntax	Description
variable=value	Assigns a value to a variable
$variable	Retrieves the value of a variable
${variable}	Alternative syntax for retrieving the value of a variable
unset variable	Removes the value of a variable
readonly variable	Makes a variable read-only
export variable	Makes a variable available to child processes

Conditional Statements

Syntax	Description
if condition; then command; fi	Executes a command if a condition is true
if condition; then command; else command; fi	Executes one command if a condition is true, and another command if it is false
if condition; then command; elif condition; then command; else command; fi	Executes one command if the first condition is true, another command if the second condition is true, and another command if both conditions are false
case variable in pattern1) command;; pattern2) command;; *) command;; esac	Executes a command based on the value of a variable

Loops

Syntax	Description
for variable in list; do command; done	Executes a command for each item in a list
while condition; do command; done	Executes a command while a condition is true
until condition; do command; done	Executes a command until a condition is true
select variable in list; do command; done	Displays a menu of options and executes a command based on the user’s selection

Functions

Syntax	Description
function_name() { command; }	Defines a function
function_name argument1 argument2	Calls a function with arguments
return value	Returns a value from a function

Input/Output

Syntax	Description
command > file	Redirects the output of a command to a file
command >> file	Appends the output of a command to a file
command < file	Redirects the input of a command from a file
command1 | command2	Pipes the output of one command to the input of another command
command &> file	Redirects both standard output and standard error to a file

References

• Bash Reference Manual