In this article, you will walk through the creation of a simple Bash shell script to send messages to Telegram messenger using the Curl command. Then you will use this script to send a notification on every ssh login into your server.
To send a message to Telegram group or channel, you should first create your own bot. Just open Telegram, find @BotFather and type
/start. Then follow instructions to create bot and get token to access the HTTP API.
Create a new Channel in Telegram and add your bot as a member. So your bot could send messages to the Channel.
In order to get Channel Id, first, post any message to the Channel. Then use this link template to get Channel Id:
Here is a response example:
In order to send a message we could use simple command:
But in programming, it is good practice to hide the low-level implementation. So we will create a linux terminal command
telegram-send and could send messages with this simple command.
Lets create file
Then add script to this file. Set your group id and token in script.
It is not a good practice to store your token in that place, but for now, it is ok. Also, you could limit actions your bot could do in the Channel only to send messages.
To run this script we should add permission
chmod +x telegram-send.sh
Now you can test it
./telegram-send.sh "Test message"
In order to use this script from everywhere and type
./telegram-send.sh add it to /usr/bin/ folder
sudo mv telegram-send.sh /usr/bin/telegram-send
Owner of all files in /usr/bin is root user. So let’s do the same with our script:
sudo chown root:root /usr/bin/telegram-send
Now you can test it
telegram-send "Test message"
All files with .sh extension in /etc/profile.d/ folder will be executed whenever a bash login shell is entered or the desktop session loads.
Let’s add a new script to send the notification.
Add this code to script
Then move this script to /etc/profile.d/ folder
sudo mv login-notify.sh /etc/profile.d/login-notify.sh
Now re-login to your web server and check it works.