if_statements.md

IF Statements in Bash

IF statment

if [ condition ]; then
    # Code to execute if condition is true
fi

IF ELSE statement

if [ condition ]; then
    # Code to execute if condition is true
else
    # Code to execute if condition is false
fi

ELSE IF statement

if [ condition1 ]; then
    # Code to execute if condition1 is true
elif [ condition2 ]; then
    # Code to execute if condition2 is true
else
    # Code to execute if all conditions are false
fi

CASE statement

case "$variable" in
    pattern1)
        # Code to execute for pattern1
        ;;
    pattern2)
        # Code to execute for pattern2
        ;;
    *)
        # Code to execute if no patterns match
        ;;
esac

Test conditions:

Bash uses the test command (or [) to evaluate conditions. Here are some common tests:

• -eq: Equal
• -ne: Not equal
• -lt: Less than
• -le: Less than or equal
• -gt: Greater than
• -ge: Greater than or equal
• -z: Empty string
• -n: Non-empty string
• !: Logical NOT
• -f: Check if file exists and is a regular file
• -d: Check if directory exists

Logical operators:

You can combine conditions using logical operators:

• &&: Logical AND
• ||: Logical OR