Bash Script Operator Reference

This page contains a reference of helpful operators that can be used in Bash scripts.

You can learn more about (most) of these operators in the article on Bash operators.

Arithmetic Operators

• + (Addition)
• - (Subtraction)
• * (Multiplication)
• / (Division)
• % (Modulus)

Comparison Operators

• -eq (Equal to)
• -ne (Not equal to)
• -lt (Less than)
• -le (Less than or equal to)
• -gt (Greater than)
• -ge (Greater than or equal to)

String Operators

• = (Equal to)
• != (Not equal to)
• -z (Empty string)
• -n (Non-empty string)
• > (Greater than, in ASCII order)
• < (Less than, in ASCII order)

Logical Operators

• ! (Logical NOT)
• && (Logical AND)
• || (Logical OR)

File Test Operators

• -e (File exists)
• -f (File is a regular file)
• -d (File is a directory)
• -r (File is readable)
• -w (File is writable)
• -x (File is executable)

Assignment Operators

• = (Simple assignment)
• += (Add and assign to variable)
• -= (Subtract and assign)
• *= (Multiply and assign)
• /= (Divide and assign)

Miscellaneous Operators

• : (Null command, does nothing, used for syntax purposes)
• . (Source a script, execute commands in the current shell)

These operators can be combined with conditional statements (if, elif, else) and loops (for, while, until) to build complex scripts for various purposes.