diff --git a/README.md b/README.md index 709e979..28040e3 100644 --- a/README.md +++ b/README.md @@ -3,28 +3,67 @@

## Table of Contents - 1. [Basic Operations](#1-basic-operations) - 1.1. [File Operations](#11-file-operations) - 1.2. [Text Operations](#12-text-operations) - 1.3. [Directory Operations](#13-directory-operations) - 1.4. [SSH, System Info & Network Operations](#14-ssh-system-info--network-operations) - 1.5. [Process Monitoring Operations](#15-process-monitoring-operations) - 2. [Basic Shell Programming](#2-basic-shell-programming) - 2.1. [Variables](#21-variables) - 2.2. [Array](#22-array) - 2.3. [String Substitution](#23-string-substitution) - 2.4. [Other String Tricks](#24-other-string-tricks) - 2.5. [Functions](#25-functions) - 2.6. [Conditionals](#26-conditionals) - 2.7. [Loops](#27-loops) - 3. [Tricks](#3-tricks) - 4. [Debugging](#4-debugging) - 5. [Multi-threading](#5-multi-threading) + + 1. [Basic Operations](#basic-operations) + 1.1. [File Operations](#file-operations) + 1.2. [Text Operations](#text-operations) + 1.3. [Directory Operations](#directory-operations) + 1.4. [SSH, System Info & Network Operations](#ssh-system-info--network-operations) + 1.5. [Process Monitoring Operations](#process-monitoring-operations) + 1.6. [Redirections and Piping](#redirections-and-piping) + 1.6.1. [`>`](#greater-than) + 1.6.2. [`>>`](#double-greater-than) + 1.6.3. [`|`](#pipe) + 1.7. [Permission Management](#permission-management) + 1.7.1. [chmod](#chmod) + 1.7.2. [chown](#chown) + 1.7.3. [chgrp](#chgrp) + 1.8. [Pattern Search and Manipulation](#pattern-search-and-manipulation) + 1.8.1. [grep](#grep) + 1.8.2. [awk](#awk) + 1.8.3. [sed](#sed) + + 2. [Basic Shell Programming](#basic-shell-programming) + 2.1. [Variables](#variables) + 2.2. [Array](#array) + 2.3. [String Substitution](#string-substitution) + 2.4. [Other String Tricks](#other-string-tricks) + 2.5. [Functions](#functions) + 2.6. [Conditionals](#conditionals) + 2.7. [Loops](#loops) + 2.8. [Working with History](#working-with-history) + 2.8.1. [history](#history) + 2.8.2. [History Shortcuts and Tricks](#history-shortcuts) + 2.9. [Advanced Shell Programming](#advanced-shell-programming) + 2.9.1. [trap](#trap) + 2.9.2. [getopts](#getopts) + 2.10. [Interacting with Other Languages](#interacting-with-other-languages) + 2.10.1. [Executing Other Languages](#executing-other-languages) + 2.10.2. [Running SQL Commands from Bash](#sql-from-bash) + 2.11. [Use of Additional Tools](#use-of-additional-tools) + 2.11.1. [tmux](#tmux) + 2.11.2. [wget](#wget) + + 3. [Tricks](#tricks) + 3.1. [Best Practices](#best-practices) + 3.1.1. [Writing Style](#writing-style) + 3.1.2. [Tips for Maintainability](#maintainability-tips) + 3.2. [Environments and Profiles](#environments-and-profiles) + 3.2.1. [`.bashrc vs .bash_profile`](#bashrc-vs-bash_profile) + 3.2.2. [Custom Aliases](#custom-aliases) + 3.3. [Package and Software Management](#package-and-software-management) + 3.3.1. [Package Managers](#package-managers) + 3.3.2. [Installation from Source Code](#source-code-installation) + 3.4. [Archiving and Compression](#archiving-and-compression) + 4.1. [tar](#tar) + 4.2. [Compression Tools](#compression-tools) + 4. [Debugging](#debugging) + 5. [Multi-threading](#multi-threading) # 1. Basic Operations ### a. `export` -Displays all environment variables. If you want to get details of a specific variable, use `echo $VARIABLE_NAME`. +Displays all environment variables. If you want to get details of a specific variable, use `echo $VARIABLE_NAME`. ```bash export ``` @@ -957,8 +996,75 @@ Combine it with `&` to create background processes nohup command & ``` -# 2. Basic Shell Programming +## 1.6. Redirections and Piping + + + + + + +
Input,Output, and Error RedirectionUsing pipe '|' to connect commands
+ +### a. `imput,output,errorRedirection` +Redirects input, output, or errors to/from files or commands. +```bash +command > output.txt # Redirects output +command 2> error.txt # Redirects errors +command < input.txt # Redirects input +``` +Example: +``` +$ echo "Hello, World!" > hello.txt +$ cat < hello.txt +Hello, World! +``` + +### b. `pipe` +Pipe the output of one command into another +```bash +command1 | command2 +``` +Example: +```bash +$ echo "Hello, World!" | awk '{print $2}' +World! +``` +## 1.7. Permisions managment + + + + + + + + +
chmodchownchgrpumask
+ +### a. `chmod` +Change files permissions. +```bash +chmod [permissions] [file] +``` + +### b. `chown` +Change file owner +```bash +chown [owner]:[group] [file] +``` + +### c. `chgrp` +Change group ownership of a file +```bash +chgrp [group] [file] +``` + +### d. `umask` +Set default permisions for newly created files +```bash +umask [value] +``` +# 2. Basic Shell Programming The first line that you will write in bash script files is called `shebang`. This line in any script determines the script's ability to be executed like a standalone executable without typing sh, bash, python, php etc beforehand in the terminal.