initialise_testing_debian_stable.bash

#!/bin/bash
# Bash script to setup testing alongside stable on Debian.
# Based on http://serverfault.com/a/382101
# with fixes from http://serverfault.com/a/653552

# FUNCTIONS #
# This is a general-purpose function to ask Yes/No questions in Bash, either
# with or without a default answer. It keeps repeating the question until it
# gets a valid answer.
# https://gist.github.com/davejamesmiller/1965569
ask() {
    # http://djm.me/ask
    while true; do

        if [ "${2:-}" = "Y" ]; then
            prompt="Y/n"
            default=Y
        elif [ "${2:-}" = "N" ]; then
            prompt="y/N"
            default=N
        else
            prompt="y/n"
            default=
        fi

        # Ask the question - use /dev/tty in case stdin is redirected from somewhere else
        read -p "$1 [$prompt] " REPLY </dev/tty

        # Default?
        if [ -z "$REPLY" ]; then
            REPLY=$default
        fi

        # Check if the reply is valid
        case "$REPLY" in
            Y*|y*) return 0 ;;
            N*|n*) return 1 ;;
        esac

    done
}

if [[ $# -eq 0 ]] ; then
    echo "Missing argument: mirror (http://ftp.nluug.nl/pub/os/Linux/distr/debian/)"
    exit 0
fi
echo "Creating files in /etc/apt/preferences.d..."
cat > /etc/apt/preferences.d/security.pref <<EOF
Package: *
Pin: release l=Debian-Security
Pin-Priority: 900
EOF
cat > /etc/apt/preferences.d/stable.pref <<EOF
Package: *
Pin: release a=stable
Pin-Priority: 995
EOF
cat > /etc/apt/preferences.d/testing.pref <<EOF
Package: *
Pin: release a=testing
Pin-Priority: 750
EOF
cat > /etc/apt/preferences.d/unstable.pref <<EOF
Package: *
Pin: release a=unstable
Pin-Priority: 50
EOF
cat > /etc/apt/preferences.d/experimental.pref <<EOF
Package: *
Pin: release a=experimental
Pin-Priority: 1
EOF
echo "Created files in /etc/apt/preferences.d"
echo ""
echo "Creating files in /etc/apt/sources.list.d"
cat > /etc/apt/sources.list.d/security.list <<EOF
deb     http://security.debian.org/         stable/updates  main contrib non-free
deb     http://security.debian.org/         testing/updates main contrib non-free
EOF
cat > /etc/apt/sources.list.d/stable.list <<EOF
deb     $1 stable main contrib non-free
deb-src $1 stable main contrib non-free
deb     http://ftp.debian.org/debian/    stable main contrib non-free
deb-src http://ftp.debian.org/debian/    stable main contrib non-free
EOF
cat > /etc/apt/sources.list.d/testing.list <<EOF
deb     $1 testing main contrib non-free
deb-src $1 testing main contrib non-free
deb     http://ftp.debian.org/debian/    testing main contrib non-free
deb-src http://ftp.debian.org/debian/    testing main contrib non-free
EOF
cat > /etc/apt/sources.list.d/unstable.list <<EOF
deb     $1 unstable main contrib non-free
deb-src $1 unstable main contrib non-free
deb     http://ftp.debian.org/debian/    unstable main contrib non-free
deb-src http://ftp.debian.org/debian/    unstable main contrib non-free
EOF
cat > /etc/apt/sources.list.d/experimental.list <<EOF
deb     $1 experimental main contrib non-free
deb-src $1 experimental main contrib non-free
deb     http://ftp.debian.org/debian/    experimental main contrib non-free
deb-src http://ftp.debian.org/debian/    experimental main contrib non-free
EOF
echo "Created files in /etc/apt/sources.list.d"
echo ""
# Default to No if the user presses enter without giving an answer:
if ask "Do you want to run apt-get update now?" N; then
    sudo apt-get update
    echo ""
    echo "Done! Testing enabled."
else
    echo ""
    echo "Ok. Please verify the files and run apt-get update manually later."
fi