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01bash

What is Bash? 🤔⚓︎

  • A bash script is a file containing a sequence of commands that are executed by the bash program line by line. It allows you to perform a series of actions, such as navigating to a specific directory, creating a folder, and launching a process using the command line.
  • By saving these commands in a script, you can repeat the same sequence of steps multiple times and execute them by running the script.

Advantages of Bash scripting 🤩⚓︎

Bash scripting is a powerful and versatile tool for automating system administration tasks, managing system resources, and performing other routine tasks in Unix/Linux systems. Some advantages of shell scripting are:

  • Automation: Shell scripts allow you to automate repetitive tasks and processes, saving time and reducing the risk of errors that can occur with manual execution.
  • Portability: Shell scripts can be run on various platforms and operating systems, including Unix, Linux, macOS, and even Windows through the use of emulators or virtual machines.
  • Flexibility: Shell scripts are highly customizable and can be easily modified to suit specific requirements. They can also be combined with other programming languages or utilities to create more powerful scripts.
  • Accessibility: Shell scripts are easy to write and don't require any special tools or software. They can be edited using any text editor, and most operating systems have a built-in shell interpreter.
  • Integration: Shell scripts can be integrated with other tools and applications, such as databases, web servers, and cloud services, allowing for more complex automation and system management tasks.
  • Debugging: Shell scripts are easy to debug, and most shells have built-in debugging and error-reporting tools that can help identify and fix issues quickly.

Certainly! Bash, short for "Bourne Again SHell," is a command processor that typically runs in a text window where the user types commands that cause actions. It is one of the most widely used Unix shells, serving as the default shell for many Unix-like operating systems, including Linux.

  • BASH is an acronym for Bourne Again Shell, a punning name, which is a tribute to Bourne Shell (i.e., invented by Steven Bourne).

  • Bash is a shell program written by Brian Fox as an upgraded version of Bourne Shell program 'sh'. It is an open source GNU project. It was released in 1989 as one of the most popular shell distribution of GNU/Linux operating systems. It provides functional improvements over Bourne Shell for both programming and interactive uses. It includes command line editing, key bindings, command history with unlimited size, etc.

  • In basic terms, Bash is a command line interpreter that typically runs in a text window where user can interpret commands to carry out various actions. The combination of these commands as a series within a file is known as a Shell Script. Bash can read and execute the commands from a Shell Script.
  • Bash is the default login shell for most Linux distributions and Apple's mac OS. It is also accessible for Windows 10 with a version and default user shell in Solaris 11.
  • BASH is an acronym for Bourne Again Shell, a punning name, which is a tribute to Bourne Shell (i.e., invented by Steven Bourne).
  • Bash is a shell program written by Brian Fox as an upgraded version of Bourne Shell program 'sh'. It is an open source GNU project. It was released in 1989 as one of the most popular shell distribution of GNU/Linux operating systems. It provides functional improvements over Bourne Shell for both programming and interactive uses. It includes command line editing, key bindings, command history with unlimited size, etc.
  • In basic terms, Bash is a command line interpreter that typically runs in a text window where user can interpret commands to carry out various actions. The combination of these commands as a series within a file is known as a Shell Script. Bash can read and execute the commands from a Shell Script.
  • Bash is the default login shell for most Linux distributions and Apple's mac OS. It is also accessible for Windows 10 with a version and default user shell in Solaris 11.

Shell: A UNIX Shell is a program or a command line interpreter that interprets the user commands which are either entered by the user directly or which can be read from a file (i.e., Shall Script), and then pass them to the operating system for processing. It is important to note that Shall scripts are interpreted and not compiled, as the computer system interprets them and there is not any need to compile Shell Scripts in order of execution.

There are different types of shells available in Linux Operating Systems. Some of which are as follows:⚓︎

  1. Bourne Shell
  2. C shell
  3. Korn Shell
  4. GNU Bourne Shell

To know, which shell types your operating system supports, type the command into the terminal as given below:

cat /etc/shells

And to know where bash is located in your OS, type the below command and you will get a specific location:

which bash

History of Bash 🔄⚓︎

  • Previously, most of the software in the UNIX world was proprietary and closed source. UNIX system was also not open-sourced for which, you had to use a shell. There was a shell existed at that time named by "Bourne Shell" under the /bin/sh command which was proprietary and closed source. Bourne named after its inventor- Steven Bourne.
  • Richard Stallman at that time began GNU project with Free Software Foundation (FSF) to create a UNIX-compatible operating system aiming everything as open-source. There was a lack of progress in the revolution. He needed a free shell that could run existing shell scripts. It was imperative to a completely open-source system built as one of the few projects he funded with FSF. Then on January 110, 1988, - -
  • Brian Fox (FSF employee) began coding on Bash and released Bash as beta, version 0.99 on June 8, 1989. Brian Fox remained in FSF as the primary Bash maintainer till 1993. Then he laid off from FSF, and Chet Ramey (earlier contributor in FSF) got his responsibility.
  • Further, on December 23, 1996, Chet Ramey released another bash version 2.0 for the public with a range of new features over the old bash version.
  • And now Chet Ramey is known for the official bash maintainer, and he continues to make further enhancements in bash.

Bash is the standard shell included with Linux. It is the most popular shell known today of being open-source and also with various productive features we read in the further topic. It is available for Linux distributions, macOS, Solaris 11, and Windows 10 too. It is offering the best experience for its users with a lot of improvements.

Importance of shell scripting in automation 📌📌⚓︎

Shell scripting plays a crucial role in automation, providing a means to streamline, optimize, and automate various tasks and processes within a computing environment. Here are some detailed explanations of the importance of shell scripting in automation:

  1. Task Automation:

  2. One of the primary purposes of shell scripting is to automate repetitive tasks. By writing scripts, users can encapsulate a series of commands or operations into a single script file, reducing the need for manual intervention.

  3. Time Efficiency:

  4. Automation with shell scripts saves time by eliminating the need to perform repetitive tasks manually. Scripts can be scheduled to run at specific times or triggered by events, allowing tasks to be executed automatically without constant user supervision.

  5. Consistency and Accuracy:

  6. Shell scripts ensure consistency and accuracy in task execution. Human errors are common when performing repetitive tasks manually, but scripts follow a predefined sequence of commands, minimizing the chances of mistakes.

  7. Batch Processing:

  8. Shell scripting is particularly useful for batch processing, where a large number of similar tasks need to be executed sequentially. This could include tasks like processing files, renaming multiple files, or running the same operation on various data sets.

  9. System Administration:

  10. System administrators use shell scripts extensively for managing and maintaining systems. Tasks such as system backups, log rotation, user management, and software installations can be automated with scripts, allowing administrators to focus on more complex issues.

  11. Resource Management:

  12. Automation scripts can help in monitoring and managing system resources efficiently. For instance, scripts can be written to monitor CPU usage, disk space, or memory usage and take appropriate actions, such as sending alerts or automatically adjusting configurations.

  13. Configuration Management:

  14. Shell scripting is instrumental in configuring and maintaining the settings of various applications and services. Configuration files can be modified, and services restarted automatically through scripts, ensuring that systems remain configured as desired.

  15. Error Handling and Logging:

  16. Shell scripts can include error-handling mechanisms and logging functionality. This ensures that in case of errors, the script can gracefully handle the situation, log relevant information, and send notifications to administrators.

  17. Cross-Platform Compatibility:

  18. Many shell scripts are designed to be portable and can run across different Unix-like operating systems. This cross-platform compatibility allows for the creation of scripts that can be used on various systems without modification.

  19. Integration with Other Tools:

    • Shell scripts can be integrated with other tools and utilities, creating a comprehensive automation solution. For example, scripts can invoke command-line tools, APIs, or even other scripts to achieve complex automation workflows.

  20. Customization and Extensibility:

    • Shell scripting provides a highly customizable and extensible environment. Users can create scripts tailored to their specific needs, adding new functionalities or modifying existing ones as requirements evolve.