apt-get hold / un-hold debian package

apt-hold

#!/bin/bash
#
# To hold one or more packages:
#   apt-hold <pkg> [pkg2 ...]
#
# To un-hold one ore more packages:
#   apt-hold -u <pkg> [pkg2 ...]
# or if this script is symlinked as apt-unhold:
#   apt-unhold <pkg> [pkg2 ...]

function display_usage {
    while [ $# -gt 0 ]; do echo "$1" 1>&2; shift; done
    echo "Place APT packages on hold." 1>&2
    echo "usage: $(basename $0) [pkgname...]" 1>&2
    exit 1
}

function apt_hold {
    local pkg="$1"
    dpkg --get-selections | egrep -q "\\b${pkg}\\b\\s*install"
    if [ $? -ne 0 ]
    then
        echo "${pkg} is not set for install"
        return 0
    fi
    echo "Marking ${pkg} for holding"
    echo "${pkg} hold" | dpkg --set-selections
    return $?
}

function apt_unhold {
    local pkg="$1"
    dpkg --get-selections | egrep -q "\\b${pkg}\\b\\s*hold"
    if [ $? -ne 0 ]
    then
        echo "${pkg} is not set for hold"
        return 0
    fi
    echo "Marking ${pkg} for installation"
    echo "${pkg} install" | dpkg --set-selections
    return $?
}


if [ $EUID -ne 0 ]
then
    echo "root privileges required."
    exit 1
fi

PKG_NAMES=""
DO_UNHOLD=0
[ "$(basename $0)" == "apt-unhold" ] && DO_UNHOLD=1

while [ $# -gt 0 ]
do
    case "$1" in
        "-h"|"--help") display_usage;;
        "-u"|"--unhold") DO_UNHOLD=1;;
        *)
            export PKG_NAMES="${PKG_NAMES} $1"
        ;;
    esac
    shift
done

if [ -z "${PKG_NAMES}" ]
then
    dpkg --get-selections | grep hold
    if [ $? -ne 0 ]
    then
        echo "No packages are being held."
    fi
    exit 0
fi

for pkg in ${PKG_NAMES}
do
    if [ $DO_UNHOLD -eq 1 ]
    then
        apt_unhold "${pkg}"
    else
        apt_hold "${pkg}"
    fi
done