POSTIN

/bin/sh

if [ ! -f /etc/shells ]; then
	echo "/bin/tcsh" >> /etc/shells
	echo "/bin/csh"  >> /etc/shells
else
	grep -q '^/bin/tcsh$' /etc/shells || \
	echo "/bin/tcsh" >> /etc/shells
	grep -q '^/bin/csh$'  /etc/shells || \
	echo "/bin/csh"  >> /etc/shells
fi

POSTUN

/bin/sh

if [ ! -x /bin/tcsh ]; then
	grep -v '^/bin/tcsh$'  /etc/shells | \
	grep -v '^/bin/csh$' > /etc/shells.rpm
	cat /etc/shells.rpm > /etc/shells && rm /etc/shells.rpm
fi