postinst is in fizsh 1.0.2-1.
This file is a maintainer script. It is executed when installing (*inst) or removing (*rm) the package.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 | #!/bin/sh
#
#
set -e
fizsh=$(which fizsh)
/etc/fizsh/modify-etc-shells.zsh --add $fizsh
exit 0
|