Terminal what is bash

The script only has two lines. The first indicates what interpreter to use to run the file in this case, bash. It is due to the permissions set on the file.

To avoid that use:. Cat is used to read a file sequentially and print it to the standard output. The name is derived from its function to con cat enate files. Change Directory to the path specified, for example cd projects. Head is used to print the first ten lines by default or any other amount specified of a file or files. The head command allows you to view the first N lines of a file. Choosing to display the file header is optional using the option below.

It's not the usual automation that makes the difference, though; it's the bespoke workflows that people invent for themselves, the things nobody else thinks need automation. When experienced users say that they want to learn Bash, if they don't mean they want to learn Linux commands, then they probably mean that they want to improve the way they script their commands. For instance, this is an extremely rudimentary Bash script that converts a temporary file imagine it's a file created by a separate process to a specific directory:.

That's valid Bash. You can verify it by copying and pasting the command the last line beginning with cp into a terminal. As long as there's a file called tmp. Learning Bash, though, is all about understanding how a simple command like this can be improved for the sake of automation.

For instance, if the file tmp. If this script is a key component to, for instance, a blogging site that requires a new image each day so that a custom header image can be constructed, then the script's failure could cause catastrophic errors elsewhere. A user who knows Bash could add resiliency using Bash syntax:. This is just one example of the process of learning to script with Bash, but it demonstrates how learning both Linux and Bash are equally useful and not entirely separate tasks.

Bash is as powerful as other shells but adds convenience functions like the double brackets [[ and ]] in the sample code. These "Bashisms" are much loved by Bash users because they avoid the sometimes verbose and awkward syntax in other shells like tcsh or ash.

Then again, Bash is open source free software , so most users can install it if they need it. The lack of compatibility only forces an extra dependency and does not exclude anyone from using a script. If you've been using Linux for long at all, you've no doubt seen the word Bash thrown around in forums and articles. It sometimes seems like a synonym for the terminal, but Bash and the terminal emulator are definitely two different applications. So what is Bash exactly? In this short article, we'll explore what Bash is, what it does, and how you can start using it.

The first beta was released in , and, as of this writing, has seen its most recent update in December version 5. Bash is among the most popular of shell languages, known for its combination of powerful capabilities and user-friendly commands. That's why it's so prolific across Linux distributions. A shell is an application that accepts input from a user and executes an action in response, typically communicating with the kernel to make that happen.

In that way, it's like a "shell" around the kernel. Davidenko 1, 4 4 gold badges 16 16 silver badges 31 31 bronze badges. Koray Tugay Koray Tugay 1, 5 5 gold badges 21 21 silver badges 35 35 bronze badges. The provided question marked as origin for this "presumed" duplicate is not appropriate. That question is referring to the general understanding between a shell and a terminal, not the difference between the certain applications of bash and terminal in Linux or macOS.

Of course this question rather would be in the Ubuntu forum askubuntu. Add a comment. Active Oldest Votes. Improve this answer. But why doesn't it say bash the first time it is opened? Btw this was the answer I was looking for thanks, it is clear now.. I will give the bounty to you once the required time expires.

Thanks, this is a great great answer.. The export keyword does exactly that: marks the variable for "export" to child processes.

Could you please see this: pastebin. It's also not set up to be inherited by child shells" but the paths are same for both the first bash and the bash inside the bash? Check my previous comment: your profile script says " export PATH…", and exported variables are inherited by child processes - unlike your PS1 which isn't set to be exported.

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