JOIN(1) JOIN(1) (NAME) join - (SYNOPSIS) join []... (DESCRIPTION) . . - . -a FILENUM FILENUM ( ) -e STRING STRING -i, --ignore-case -j FIELD '-1 FIELD -2 FIELD' -o FORMAT FORMAT -t CHAR CHAR -v FILENUM -a FILENUM -1 FIELD FIELD -2 FIELD FIELD --check-order --nocheck-order --help --version (SEE ALSO) comm(1), sort(1) GNU coreutils 9.11 July 2026 JOIN(1)