Users and groups in Linux

useradd -g oinstall -G asmadmin,asmdba,asmoper,dba,asmdba grid
usermod -a -G asmadmin oracle
usermod -a -G asmoper oracle
usermod -a -G asmdba oracle
usermod -a -G oinstall oracle
usermod -a -G oinstall grid

$ grep ‘grpup-name-here’ /etc/group
$ grep ‘ftponly’ /etc/group
$ grep -i color ‘ftponly’ /etc/group