-N FILE (conditional operator)

true if the file exists and has been modified since it was last read.

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

Links

• Bash manual
• POSIX specification of test

Examples

Different ways to test if a file was modified since it was last read:

1 2 3 4

test -N ~/file && echo "modified" [ -N ~/file ] && echo "modified" # Bash [[ -N ~/file ]] && echo "modified"