Get Free cronjob from Cron-Job.org!

Cronjob or CRON is an important tool to perform automated / schedule task for web application.

Some shared hosting company may limit (or completely disable) the cron service functionality leading to some web application unable to perform periodic / automated task.

Luckily there’s website such as Cron-Job.org which offers free cron-job to those who aren’t able to obtain one.

The best thing about Cron-Job.org service, is they allow minute-by-minute cronjob execution for free!

 

Bonus: The folks at Cron-Job also releases  the source code behind the service at GitHub!

A Bash script for sending telegram messages in Linux

Would it be nice to be able to receive notification from your Linux system in Telegram?

t_logo

I’ve come up with a rudimentary bash script which lets you integrate the telegram-cli into your own script which is useful for sending messages or notification within automated process to your Telegram account.

The bash script is very useful when you want to send notification to your Telegram account. Example usage: notifying you instantly whenever a backup has been completed or whenever somebody logged into your system or if there’s a brute-force attempt to log into your SSH. Basically anything that you can imagine!

First Step: Install telegram-cli

The first step is to install the telegram-cli client on your Linux system. You may choose to:

  1. Build it on your own – using source code, or
  2. Install telegram-cli from *.deb (Ubuntu LTS only)

IMPORTANT: Please read on how to initialize and sign-in the telegram-cli and key in the required telegram “CODE” in your phone.

Second Step: Copy send-telegram.sh script to /usr/local/bin

You may copy this telegram bash script and chmod it to be executed from command line (up to you).

Download the script at: https://blog.mypapit.net/upload/files/send-telegram.sh.txt

#!/bin/bash
######
###
# telegram-cli bash script r0.1
# change 'to' to your own  Telegram account name
# by =  Mohammad Hafiz bin Ismail  [mypapit@gmail.com]
# url=  https://blog.mypapit.net/
###
######

## Replace 'to' with your account name

to=Replace_this_with_your-Telegram_account_name
##


function show_usage {

 echo "Usage $0 [message]"
 exit
}




if [ $# -lt 1 ]
then
  show_usage
fi


telegram-cli -W -e "msg $to $1"

IMPORTANT: Do not forget to “chmod a+x” the “send-telegram.sh” script.
IMPORTANT: Change the “to” variable in the script to match your own Telegram username.

Third Step: Using the send-telegram.sh script

Using the send-telegram.sh is easy!

Once you’ve logged in and initialized your telegram-cli application. You only need to execute the “send-telegram.sh” to send instant messages to your Telegram account!

Just do this

wget -c https://blog.mypapit.net/upload/files/send-telegram.sh.txt
cp send-telegram.sh.txt /usr/local/bin/send-telegram.sh

Then chmod it, to make it executable,

sudo chmod a+x  /usr/local/bin/send-telegram.sh

IMPORTANT: Change the “to” variable in the send-telegram.sh script to match your own Telegram username.

sudo nano /usr/local/bin/send-telegram.sh

To test your telegram script, just make sure you’ve logged into Telegram and telegram-cli, and have entered the correct activation “CODE”. Read Step 1, if you are unsure.

Then you may try out the send-telegram.sh script

send-telegram.sh "this is my message"

To send telegram message with timestamp type:

send-telegram.sh "`date -I` : this is a message with timestamp"

What should I do next?

Use your imagination! You can integrate this script in crontab, or put it inside another another bash script or conditional operation, or even launch it from a web application, the potential is limitless.

Happy trying!

How to optimize MySQL tables automatically using cron

Busy websites which has a lot of insert/delete transactions may introduce fragmentation in MySQL tables. Fortunately, users and optimize mysql tables with ‘OPTIMIZE TABLE’ command, but how to execute it automatically?

Here’s how:
The mysql-client package in Ubuntu installation comes with a tool called mysqlcheck which is handy for optimizing table in mysql. This command can be executed from bash and can be executed using cron.

to do that, just run this command.

[bash]
cron -e

#in the crontab file– add this line
59 23 * * * /usr/bin/mysqlcheck -o -v -u <mysql username> -h localhost <database_name> -p <password>
[/bash]

This will tell cron to execute mysqlcheck and optimize mysql table of the specified database exactly on 11:59pm, every day. You can change the setting to suit your need.