if

all

Perform conditional processing in shell scripts. See also: `test`, `[`.

Examples (8)

Execute the specified commands if the condition command's exit status is zero

if condition_command; then echo "Condition is true"; fi

Execute the specified commands if the condition command's exit status is not zero

if ! condition_command; then echo "Condition is true"; fi

Execute the first specified commands if the condition command's exit status is zero otherwise execute the second specified commands

if condition_command; then echo "Condition is true"; else echo "Condition is false"; fi

Check whether a [f]ile exists

if [[ -f path/to/file ]]; then echo "Condition is true"; fi

Check whether a [d]irectory exists

if [[ -d path/to/directory ]]; then echo "Condition is true"; fi

Check whether a file or directory [e]xists

if [[ -e path/to/file_or_directory ]]; then echo "Condition is true"; fi

Check whether a variable is defined

if [[ -n "$variable" ]]; then echo "Condition is true"; fi

List all possible conditions (`test` is an alias to `[`; both are commonly used with `if`)

man test