A shell is an important layer of Linux architecture. Shell is an interface which takes input from Users and sends instructions to the Kernel, Also takes the output from Kernel and send the result back to output shell. In this tutorial, we use Bash shell for the examples. Basically a shell is of two...
An array is a data structure consist multiple elements based on key pair basis. Each array element is accessible via a key index number. This tutorial will help you to create an Array in bash script. Also, initialize an array, add an element, update element and delete an element in the bash script. Define...
The Python subprocess module allows to spawn new processes, execute external commands from Python scripts. You can install the latest version of Python using these tutorials. Also, there is number of IDE available for Python. Like Install PyCharm Python IDE on Ubuntu systems. A Simple Python Example Let’s create your first program to list...
Question. I am running a Linux system (Ubuntu) system. Its root user has 100K emails to their mailbox. How do I remove all emails from the root mailbox? How can I remove all emails using shell prompt on Linux system? This tutorial will help you delete all root user emails from the shell in...
In our previous docker tutorials your learned about how to Install Docker on CentOS or Install Docker on Debian based system. Also, write tutorials about how to create or delete docker containers. This tutorial will help you to get shell access to your running docker container. #1. Using Docker Attach You can get bash...
While working with the Linux systems, we used many of commands on daily basis. Most of the commands are available in binary format in /bin, /sbin , /usr/bin, /usr/sbin, etc directories. As a system administrator or student we wrote many of shell script to do few task or automate them. This article will help...
This is good to test a file has enough permission to do read, write or execute operations. For a good programmer, you should use these functions before doing any operations on the file. 1. Test read permission: Below script will check if the given file has read permission for currently logged in user. This...
A Command-line Arguments are passed after the name of a program in command-line operating systems like DOS or Linux and are passed into the program from the operating system. Shell scripts also accept command line arguments similar to nix commands. Command line arguments are useful for passing input to script at runtime which has...
Similar to for loop, while loop is also entry restricted loop. It means condition is checked before executing while loop. Mostly it also can do all the works which for loop can do but in uses it has own benefit of use in programming. Syntax: while [ condition ] do // programme to execute...
While Loop: while read line do echo $line done < /tmp/file.txt Note: “line” is a variable which contains a single line read from file. Example:- Some times we required to read file content line by line inside shell a script. For this example this script will read /etc/passwd file line by line and print...