User:Cicku/Drafts/Take account of shells file

Preamble

/etc/shells is a text file which controls system login shell of users. It contains a set of valid shells which can be used in the system.

See: SHELLS(5)

How to handle new shells in Fedora packages

As this file can be edited by any people as default, we need to first determine if relevant lines are already existed. If existed already, then just echo relevant binary path to the file. Thus, here is an example of package with shell "foo" underneath /usr/bin:

%post
if [ "$1" = 1 ]; then
  if [ ! -f %{_sysconfdir}/shells ] ; then
    echo "%{_bindir}/foo" > %{_sysconfdir}/shells
  else
    grep -q "^%{_bindir}/foo$" %{_sysconfdir}/shells || echo "%{_bindir}/foo" >> %{_sysconfdir}/shells
fi

%postun
if [ "$1" = 0 ] && [ -f %{_sysconfdir}/shells ] ; then
  sed -i '\!^%{_bindir}/foo$!d' %{_sysconfdir}/shells
fi