Generic bash init script. Should work on both OS X and *nix. Probably won't support apps that fork. Works great for daemonizing things like python or ruby scripts.

generic_init.sh

#!/bin/bash

BasePath="$(cd $(dirname "${BASH_SOURCE[0]}")/.. && pwd)" # Absolute path. Will be CWD when run.
AppName="SomeApp"
Command="$BasePath/bin/your_script.sh"
LogFile="$BasePath/logs/run.log"
PidFile="$BasePath/pid"
ReloadSignal="USR1" # Leave this blank if your app doesn't support reloading
StopTimeout=10 # Max seconds to wait for process to terminate

# ------

isRunning() {
    pid="$(cat $PidFile 2> /dev/null )"
    if [[ $? == "0" && ! -z "$pid" ]]; then
        ps $pid > /dev/null
        return $?
    fi
    return 1
}

doStart() {
    if isRunning; then
        echo "$AppName is already running"
    else
        echo "Starting $AppName..."
        cd $BasePath &&
        exec $Command > $LogFile 2>&1 <&- &
        # This is here as a total hack. Bash doesn't actually wait for a background process to launch.
        # So sometimes $! will be empty. Waiting a second "solves" that.
        sleep 1 
        pid=$!
        echo "$pid" > $PidFile
    fi
}

doStop() {
    if isRunning; then
        pid=$(cat "$PidFile")
        echo -n "Stopping $AppName..."
        kill $pid
        sleep 1
        while isRunning; do
            timer=$(($timer + 1))
            if [[ $timer -ge $StopTimeout ]]; then
                break;
            fi
            sleep 1
            echo -n "."
        done
        echo
        if isRunning; then
            echo "Unable to stop process" >&2
            exit 1
        fi
        rm $PidFile
    else
        echo "$AppName is not running"
    fi
}

doStatus() {
    if isRunning; then
        echo "$AppName is running: $(cat $PidFile)"
    else
        echo "$AppName is not running"
        return 3
    fi
}

doReload() {
    if isRunning; then
        if [[ $ReloadSignal != "" ]]; then
            kill -s $ReloadSignal $(cat $PidFile)
        else
            echo "Reload is not supported"
        fi
    else
        echo "$AppName is not running"
        return 3
    fi
}

case "$1" in
    start)
        doStart
        ;;
    stop)
        doStop
        ;;
    restart)
        doStop
        doStart
        ;;
    status)
        doStatus
        ;;
    reload)
        doReload
        ;;
    *)
        echo "Command must be one of: start, stop, restart, status, reload"
        exit 1
        ;;
esac

TODO: add support for running command as another user. Should probably add force-reload and try-restart too.