The Essential 70 Linux Commands for DevOps

In the world of DevOps, efficiency and automation are kings. This is where Linux, with its vast array of command-line tools, shines. The command line is a powerful ally, providing direct control over the operating system and the machinery that runs your applications. Here, we introduce the top 70 Linux commands that are indispensable for DevOps engineers and system administrators. These commands form the backbone of many automated tasks, troubleshooting, and daily management of systems.

File and Directory Operations

1. ls: Unveil the contents of directories.
2. cd: Navigate through directories.
3. pwd: Display the current directory.
4. mkdir: Forge new directories.
5. touch: Create files without content.
6. cp: Duplicate files or directories.
7. mv: Relocate or rename files/directories.
8. rm: Eliminate files or directories.
9. find: Seek out files or directories.
10. grep: Filter patterns within files.

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How to Add a Progress Bar to a Shell Script

When writing shell scripts in Bash (or other *NIX shells), adding a progress bar can improve the user experience, especially when executing long-running tasks like file transfers, backups, or compressions. This post explores several techniques to implement progress bars, with different examples from the ones you’ve seen before.

1. Simple Progress Bar Using printf

A simple and effective method is using printf and \r to update the terminal line. Here’s how you can create a basic progress bar that shows the completion percentage as the task progresses:

#!/bin/bash

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How to Properly Sanitize User Input in PHP

Sanitizing user input is critical to protecting web applications from threats such as SQL injection and cross-site scripting (XSS). However, it is important to understand that there is no “catchall” function for all types of input sanitization in PHP, as different contexts require different approaches.

This blog post explores various methods for sanitizing input and securing your PHP application, covering SQL injection, XSS prevention, and safely handling user input in different contexts.

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Exiting a Shell Script Based on Process Exit Codes

In shell scripting, handling errors efficiently is crucial to ensure scripts behave as expected. One common scenario is wanting the script to stop execution when any command fails. Here’s a breakdown of several methods to manage exit codes and halt your script on errors.

Understanding $? and Exit Codes

Every command in a shell script returns an exit code, with 0 indicating success and any non-zero value indicating an error. You can access the exit code of the last executed command using $?.

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