PREUN

/bin/sh

if [ $1 = 0 ]; then
        /usr/sbin/alternatives --remove ksh /bin/ksh93
fi

POSTIN

/bin/sh

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

/usr/sbin/alternatives --install /bin/ksh ksh \
		/bin/ksh93 50 \
	--slave /usr/bin/ksh ksh-usrbin \
		/bin/ksh93 \
	--slave /usr/share/man/man1/ksh.1.gz ksh-man \
		/usr/share/man/man1/ksh93.1.gz

#if not symlink we are updating ksh where there was no alternatives before
#so replace with symlink and set alternatives
if [ ! -L /bin/ksh ]; then
        /usr/sbin/alternatives --auto ksh
	ln -sf /etc/alternatives/ksh /bin/ksh
	ln -sf /etc/alternatives/ksh-usrbin /usr/bin/ksh
	ln -sf /etc/alternatives/ksh-man /usr/share/man/man1/ksh.1.gz
fi

POSTUN

/bin/sh

if [ ! -f /bin/ksh ]; then
        grep -v '^/bin/ksh$' /etc/shells >/etc/shells.new
        mv /etc/shells.new /etc/shells
        chmod 644 /etc/shells
fi