Send Telegram messages from bash

telegram-http.sh

#!bin/bash

TELEGRAM_BOT_TOKEN="botid:token"
CHAT_ID="1234567890"

send_telegram () {
    title="$1"
    timestamp="$(date -R)"
    msg="$title\n$timestamp\n\n$(echo "$2" | sed -z -e 's|\\|\\\\|g' -e 's|\n|\\n|g' -e 's|\t|\\t|g' -e 's|\"|\\"|g')"
    entities="[{\"offset\":0,\"length\":${#title},\"type\":\"bold\"},{\"offset\":$((${#title}+1)),\"length\":${#timestamp},\"type\":\"italic\"}]"
    data="{\"chat_id\":\"$CHAT_ID\",\"text\":\"$msg\",\"entities\":$entities,\"disable_notification\": true}"
    curl -s -o /dev/null -H 'Content-Type: application/json' -d "$data" -X POST https://api.telegram.org/bot$TELEGRAM_BOT_TOKEN/sendMessage
}

telegram-readme.md

1. Create a bot

2. Get the bot's API token from @BotFather

3. Add your bot to the chat you'll be sending messages to

4. Get the ID of the chat
   Fetch bot updates and look for the chat id:

   curl https://api.telegram.org/bot$TELEGRAM_BOT_TOKEN/getUpdates | jq .message.chat.id
   

   The bot may need temporary message access: @BotFather > Bot Settings > Group Privacy > Turn off

5. Set both parameters TELEGRAM_BOT_TOKEN and CHAT_ID in telegram-http.sh

6. To send a message using the HTTP API: https://core.telegram.org/bots/api#sendmessage From another bash script, import with source /path/to/telegram-http.sh then can call the function each time you want to send a message like so send_telegram "title in bold" "this is the message body".

   Output: title in bold Sat, 07 Oct 2022 00:24:57 +0100 this is the message body