postinst is in php-smbclient 0.8.0~rc1-2.
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 13 14 | #!/bin/sh
set -e
# Automatically added by dh_php
if [ -e /usr/lib/php/php-maintscript-helper ] ; then
    . /usr/lib/php/php-maintscript-helper
    for conf in smbclient  ; do
        php_invoke enmod ALL ALL $conf || exit $?
    done
else
    for conf in smbclient  ; do
        phpenmod $conf
    done
fi
# End automatically added section
 |