c4wled.sh/wled

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

CURL_FLAGS="--silent --show-error --fail --ipv4 --max-filesize 64K"

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 $CURL_FLAGS --json '{"on":true}' "http://$wled_host/json")
    ;;
    off)
        api_resp=$(curl $CURL_FLAGS --json '{"on":false}' "http://$wled_host/json")
    ;;
    [1-9]|[1-9][0-7])
        api_resp=$(curl $CURL_FLAGS --json "{'on':true,'ps':$2}" "http://$wled_host/json")
    ;;
    l|list)
        echo "Presets on $wled_host:"
        curl $CURL_FLAGS "http://$wled_host/presets.json" | \
            # Split into lines - one line per preset. Append final newline.
            sed --sandbox 's/"\(1\?[0-9]\)"/\n"\1"/g; $a\' | \
            # Extract number and name of every preset.
            sed --sandbox -n 's/^"\(1\?[0-9]\)":.*"n":"\([[:print:]]*\)".*$/\1: \2/p'
        exit $?
    ;;
    dump)
        curl $CURL_FLAGS -w '\n' "http://$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