c4wled.sh/wled

#!/bin/sh
#
# Simpel command line tool to turn predefined wled instances on/off or switch
# presets.
#
# Author: Shy
# License: CC0

print_usage() {
    echo "Usage: $0 f(nordcenter)|w(ohnzimmer) on|off|1-17|list"
}

if test $# -ne 2; then
    print_usage
    exit 0
fi

# Parse host argument.
case "$1" in
    f|fnordcenter)
        wled_host='wled-fnordcenter.local'
    ;;
    w|wohnzimmer)
        wled_host='wled-wohnzimmer.local'
    ;;
    *)
        echo "Error: unknown host \"$1\"." >&2
        print_usage
        exit 1
    ;;
esac

# Parse and execute command argument.
case "$2" in
    on)
        api_resp=$(curl -s -4 --json '{"on":true}' "http://$wled_host/json")
    ;;
    off)
        api_resp=$(curl -s -4 --json '{"on":false}' "http://$wled_host/json")
    ;;
    [1-9]|[1-9][0-7])
        api_resp=$(curl -s -4 --json "{'on':true,'ps':$2}" "http://$wled_host/json")
    ;;
    l|list)
        echo "Presets on $wled_host:"
        curl -s -4 "http://$wled_host/presets.json" | \
            # Split into lines. One line per preset.
            sed --sandbox -n 's/"\([0-9]\{1,2\}\)"/\n"\1"/gp' | \
            # Extract number and name. Append final newline.
            sed --sandbox -n 's/^"\([0-9]\{1,2\}\)":.*"n":"\([[:print:]]*\)".*$/\1: \2/p; a\'
        exit $?
    ;;
    dump)
        curl -s -4 -w '\n' "http://$wled_host/json"
        exit 0
    ;;
    *)
        echo "Error: unknown command \"$2\"." >&2
        print_usage
        exit 1
    ;;
esac

curl_exit=$?
if test $curl_exit -ne 0; then
    echo "Error: curl exited with exit code $curl_exit."
    exit 1
fi

# Check API responce. Should be {"success":true}.
if test "$(echo -n "$api_resp"|tr -c -d '[:alpha:]')" != 'successtrue'; then
    echo "Error: unexpected responce from WLED API." >&2
    exit 1
fi