あなたの推し様が配信開始したら LINE に通知が来るやつ

mixch-live-notify.sh

#!/bin/sh

LIVER_ID=17861268
LIVER_NAME=ゆかりん
LINE_NOTIFY_TOKEN=SEtYoUrpeRsOnaLLInEnOtiFysaCceSStOkeNaTHEre

function get_last_started_at () {
    live_status_file=$HOME/.mixch_${LIVER_ID}_started_at
    if [ ! -f $live_status_file ]
    then
        touch $live_status_file
    fi
    cat $live_status_file
}

function set_last_started_at () {
    last_started_at=$1
    live_status_file=$HOME/.mixch_${LIVER_ID}_started_at
    /bin/echo $last_started_at > $live_status_file
}

function get_current_started_at () {
    curl -s -A 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36' \
      https://mixch.tv/u/$LIVER_ID/live \
      | grep '__INITIAL_JS_STATE__ = ' \
      | cut -d= -f2 \
      | sed 's/;$//' \
      | jq '.liveInfo.created'
}

function send_line_notify () {
    msg=$'\n'"${LIVER_NAME}がミクチャ配信を始めたよ！観に行こう！"$'\n'"https://mixch.tv/u/$LIVER_ID/live"
    curl -s -X POST -H "Authorization: Bearer $LINE_NOTIFY_TOKEN" \
      --data-urlencode "message=${msg}" \
      https://notify-api.line.me/api/notify > /dev/null
}

current_started_at=$(get_current_started_at)

if [ "$current_started_at" != "null" ]
then
    last_started_at=$(get_last_started_at)
    if [ "$last_started_at" != "$current_started_at" ]
    then
        send_line_notify
    fi
fi

set_last_started_at $current_started_at

とりあえず雑に

* * * * * /path/to/mixch-live-notify.sh > /dev/null 2>&1

みたいに設定すれば良いと思います。