3 grep -Fqx /bin/tcsh /etc/shells || echo /bin/tcsh >>/etc/shells
4 grep -Fqx /usr/bin/tcsh /etc/shells || echo /usr/bin/tcsh >>/etc/shells
7 grep -Fqx /bin/csh /etc/shells || echo /bin/csh >>/etc/shells
8 grep -Fqx /usr/bin/csh /etc/shells || echo /usr/bin/csh >>/etc/shells
17 sed -i -r '/^(\/usr)?\/bin\/tcsh$/d' etc/shells
20 sed -i -r '/^(\/usr)?\/bin\/csh$/d' etc/shells