Creating Custom Commands in Unix/Linux

Working smart means bringing maximum production from your work. In day to day life, Unix/Linux users encounter some certain set of commands which need to be executed quite frequently. Executing these commands on a regular basis may become quite irritating sometimes.

Unix/Linux systems allow us to create custom commands to cope up with this situation. Instead of executing the same set of commands every time, we can put these commands in a bash script and create a custom command. In today’s tutorial, we will create a custom command for monitoring Unix/Linux operating system with one command.

Steps To Create Custom Command in Unix/Linux

• Create a bash script
• Making the bash script executable
• Moving the bash script to /usr/bin location

Creating a Bash Script to Monitor Unix/Linux Operating Systems

We are creating a bash file with name monitoring.

vim monitoring

#!/bin/bash

        echo -e "\e[30;46m***** CURRENT LOAD *****\e[0m"
        echo Current load on Server: `cat /proc/loadavg | awk '{print $1}'`
        echo ""
        # -HostName Information
        echo -e "\e[30;46m8***** HOSTNAME INFORMATION *****\e[0m"
        hostname
        echo ""
        # -File system disk space usage:
        echo -e "\e[30;46m***** FILE SYSTEM DISK SPACE USAGE *****\e[0m"
        df -Th
        echo ""
        # -Free and used memory in the system:
        echo -e "\e[30;46m ***** FREE AND USED MEMORY *****\e[0m"
        free -h
        echo ""
        # -System uptime and load:
        echo -e "\e[30;46m***** SYSTEM UPTIME AND LOAD *****\e[0m"
        uptime
        echo ""
        # -Logged-in users:
        echo -e "\e[30;46m***** CURRENTLY LOGGED-IN USERS *****\e[0m"
        who
        echo ""
        # -Top 5 processes as far as memory usage is concerned
        echo -e "\e[30;46m***** TOP 5 MEMORY-CONSUMING PROCESSES *****\e[0m"
        ps -eo %mem,%cpu,comm --sort=-%mem | head -n 6
        echo ""
        echo -e "\e[1;32mDone.\e[0m"

Making a bash script executable

chmod +x monitoring

Moving the bash script to “/usr/bin” location

mv monitoring /usr/bin

Executing the command on Unix/Linux shell

monitoring

The output of the command

Creating custom commands will “cut corners” too hard way of executing the same set of commands again and again and also brings some sort of creativity and fun into Unix/Linux.

This brings an end to this tutorial. Visit back to find more cool stuff.

Cheers!