#!/bin/bash

# Given a script and it's content SHA-1, determine if it should run based upon
# whether its content has changed.
#
# Returns 0 if the script should run, other values indicate it should not run.
#
function should-run-script {
    local script="$1"; shift
    local script_sha1="$1"; shift
    
    if [[ -f /var/cache/runonce/$fname ]]; then
        previous_sha1=$(cat /var/cache/runonce/$fname)

        if [[ $script_sha1 == $previous_sha1 ]]; then
            return 1
        fi
    fi

    return 0
}

function main {
    local script=""

    for script in /etc/runonce.d/*; do
        local script_sha1=$(sha1sum $script |awk '{ print $1 }')

        if ! should-run-script $script $script_sha1; then
            continue;
        fi

        $script

        if [[ $? == 0 ]]; then
            local fname=$(basename $script)
            echo $script_sha1 > /var/cache/runonce/$fname
        fi
    done
}

main