Run A number of Instructions in Linux at As soon as

The Linux Terminal is a powerful tool that allows you to perform a wide variety of operations using commands. You can use these commands to perform a variety of computational tasks, including file manipulation, program management, and service automation.

If you need to run a series of terminal commands, ideally do them one at a time. It turns out, however, that there is a better way to do this, and it involves executing multiple commands at the same time.

Follow us as we demonstrate the different ways you can run multiple terminal commands on Linux.

Execute multiple Linux commands at the same time

On Linux there are three ways to run multiple commands in a terminal:

  1. the semicolon (;) Operator

  2. the Logical OR (||) Operator

  3. the Logical AND (&&) Operator

All of these methods require an operator. While any of these operators can execute two or more shell commands at the same time, knowing which operator to use and when can help you create effective commands. The following sections explain both the purpose and syntax for using these operators properly.

Related: What Is The Linux Command Line And How Is It Used?

1. Using the semicolon (;) operator

Segmenting a chain of commands with the semicolon is the most common practice when you want to execute multiple commands in a terminal. One reason for this is the way the operator works: it executes all commands in order, regardless of whether the previous command ran successfully or failed.

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For example, if there are two commands: Command A and Command B, the use of the semicolon operator in between ensures that both the first and second commands are executed sequentially regardless of the output of the first command.

Command A; Command B

So, if you're in a situation where two or more independent terminal commands need to be executed so that the output status of the first command doesn't affect the execution of the latter, the semicolon operator is the way to go.

Example use case: To display the current user name and the system host name:

Who am I ; Hostname

Note, however, that the shell executes these commands in the order in which you mention them. This is what the output would look like:

2. Using the OR operator (||)

The definition of the word "or" here is just a giveaway: when you run two commands with the OR operator, you're telling the shell to run only one command between the two.

Imagine a scenario where you used the OR operator with two commands: Command A and Command B. This is what the Conjoined command would look like with the OR operator:

Command A || Command B

Here, Command B will only run if Command A fails, d. H. if Command A returns an error. Likewise if Command A runs successfully, Command B will not be performed.

Speaking of the use case, you can use the OR operator when you need to run two related commands together so that the shell only runs the next command if the previous one fails.

Example use case: Let's say you want to create a new file, let's say Document.txt, but before you do that you want to make sure that there is no file with the same name in the current directory. In situations like this, you can run your commands in the following order:

Find . -name document.txt || Touch Document.txt

Here the find command looks for the in the current working directory Documents.txt File. If the file is found, the command history will stop – and the second command will not run.

On the other hand, if it doesn't find a suitable file, the command on the right is executed and a new file named Document.txt is created in your current working directory.

3. Using the AND operator (&&)

As you have probably guessed by now, the AND operator will only execute the next instruction in a sequence if the previous instruction was successful.

To better understand this, imagine a scenario where you want to run two related commands so that you only want the second command to run if the first returns valid output. In this case we can join the commands together using the AND operator called && to get the result we want.

Example use case: One of the most common use cases of the AND operator in Linux is to create a new directory and access it immediately. That way, you don't have to run the two commands individually to complete the operation.

For the purposes of this guide, let's assume you have a new directory called. want to create documents and immediately change your current working directory there.

mkdir documents && CD documents

Here that mkdir Command creates a new directory called documents in your current working directory. If this is successful, the cd command can be executed.

Combine multiple operators to meet your execution criteria

In addition to using operators individually in your commands, you can also group multiple operators to meet your execution criteria. This is useful when you want to run commands based on multiple conditions.

Imagine a scenario where you want to run two commands (Command B and Command C) only if Command A fails. To do this, you need to use operators as shown in the following notation:

Command A || Command B && Command C

Example use case: Suppose you want to determine if a folder (named Document) exists in your current working directory and create it if it doesn't exist. In this case, instead of running separate commands to find the directory and create a new one, you can use the OR and AND operators together to do the whole process efficiently.

This is what it would look like:

Find . -name document || echo "Directory not found" && mkdir document

At this command Find asks the shell for a folder named. to search Document in the current working directory. If the directory does not exist, the terminal transfers the flow to the echo and mkdir Commands that print the specified string or create a new folder.

Efficient execution of terminal commands on Linux

As you just saw, using operators in your commands can simplify many command line operations.

If you enjoy performing various system operations on your computer from the terminal, knowing these operators can be very helpful, and it will definitely help you to execute Linux commands more efficiently.

If you are just starting out with Linux or are less familiar, learning various terminal commands is another step in mastering the command line interface.

The Linux Commands Reference Cheat Sheet

This simple cheat sheet will help you become familiar with the Linux command line terminal in no time.

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About the author

Yash Wate
(34 articles published)

Yash is Staff Writer at MUO for DIY, Linux, programming and security. Before he discovered his passion for writing, he developed for the web and iOS. You can also find his writing on TechPP where he covers other industries. In addition to technology, he likes to talk about astronomy, Formula 1 and clocks.

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