ahuarc-dotfiles/bin/headlessvnc

#!/bin/sh
# shellcheck disable=SC2317

# cd to the local VNC directory, exit if it fails
cd "${HOME}/.vnc" || exit 5

# Variables
file_base="./$(hostname):1."
verbs="start|status|stop|restart|help"

echol() {
    col="$1"
    shift
    printf '\033['"${col}"'m%s\033[0m\n' "$*"
}

error() {
    >&2 printf '\033[1;31m%s\033[0m %s\n' "ERROR:" "$1"
    shift
    exit "$1"
}

help() {
    name="$(basename "$0")"
    cat << EOF
${name} - Start a VNC server

Usage:
    ${name} ${verbs}
EOF
}

usage() {
    >&2 help
    error "Invalid usage: ${1}" 1
}

is_running() {
    vncserver -list | grep -q '^:1'
}

start() {
    if ! is_running; then
        set -e
        vncserver \
            -xstartup xstartup \
            -localhost \
            -alwaysshared \
            -securitytypes none
    else
        error "The VNC server is already running!" 4
    fi
}

status() {
    log_f="${file_base}log"
    if is_running; then
        echol '1;32' "The VNC server is running."
        tail "$log_f"
    else
        echol '1;31' "The VNC server is not running."
    fi
}

stop() {
    if is_running; then
        vncserver -kill :1
    else
        error "The VNC server is not running!" 3
    fi
}

restart() {
    stop
    start
}

# Argument parsing
set -e; trap 'set +e; error "$error" "$?"' EXIT
error="You must give an argument"
[ -n "$1" ]; arg="$1"; shift
unset error
set +e; trap - EXIT


# Main case statement
case "$arg" in
    status|start|stop|restart|help)
        "$arg"
        ;;
    *)
        usage "Invalid argument \"$arg\""
        ;;
esac