-R VAR (conditional operator)

true if the shell variable VAR is set and is a name.

-R is not included in POSIX.1-2017.

Links

• Bash manual
• POSIX specification of test

Examples

Different ways to test if a shell variable is set and is a name:

1 2 3 4

test -R var && echo "set" [ -R var ] && echo "set" # Bash [[ -R var ]] && echo "set"