preinst is in gcc-opt 1.20.
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 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 | #! /bin/sh
# preinst script for gcc-opt
#
# see: dh_installdeb(1)
set -e
# summary of how this script can be called:
#        * <new-preinst> `install'
#        * <new-preinst> `install' <old-version>
#        * <new-preinst> `upgrade' <old-version>
#        * <old-preinst> `abort-upgrade' <new-version>
#
# for details, see http://www.debian.org/doc/debian-policy/ or
# the debian-policy package
case "$1" in
    install|upgrade)
#        if [ "$1" = "upgrade" ]
#        then
#            start-stop-daemon --stop --quiet --oknodo  \
#                --pidfile /var/run/#PACKAGE#.pid  \
#                --exec /usr/sbin/#PACKAGE# 2>/dev/null || true
#        fi
	dpkg-divert --package gcc-opt --add --rename \
		--divert /usr/bin/g++-3.3.gcc-opt /usr/bin/g++-3.3
	dpkg-divert --package gcc-opt --add --rename \
		--divert /usr/bin/gcc-3.3.gcc-opt /usr/bin/gcc-3.3
	dpkg-divert --package gcc-opt --add --rename \
		--divert /usr/bin/g++-3.4.gcc-opt /usr/bin/g++-3.4
	dpkg-divert --package gcc-opt --add --rename \
		--divert /usr/bin/gcc-3.4.gcc-opt /usr/bin/gcc-3.4
	dpkg-divert --package gcc-opt --add --rename \
		--divert /usr/bin/g++-4.0.gcc-opt /usr/bin/g++-4.0
	dpkg-divert --package gcc-opt --add --rename \
		--divert /usr/bin/gcc-4.0.gcc-opt /usr/bin/gcc-4.0
    ;;
    abort-upgrade)
    ;;
    *)
        echo "preinst called with unknown argument \`$1'" >&2
        exit 1
    ;;
esac
# dh_installdeb will replace this with shell code automatically
# generated by other debhelper scripts.
exit 0
 |