chgrp - change the group ownership of files
chgrp [-Rcfv] [--recursive] [--changes] [--silent] [--quiet] [--verbose] [--help] [--version] group file...
This manual page documents the GNU version of chgrp. chgrp changes the group ownership of each given file to the named group, which can be either a group name or a numeric group ID. OPTIONS -c, --changes Verbosely describe only files whose ownership actu- ally changes. -f, --silent, --quiet Do not print error messages about files whose own- ership cannot be changed. -v, --verbose Verbosely describe ownership changes. -R, --recursive Recursively change ownership of directories and their contents. --help Print a usage message on standard output and exit successfully. --version Print version information on standard output then exit successfully.