How to Save Output of Command in a File in Linux?

Last Updated : 24 Sep, 2024

Linux has a robust command-line interface (CLI) that makes system interaction efficient for users. Saving a command's output to a file is among the most frequent activities in Linux. When working with big outputs, generating logs, or needing to save command results for later use, this is quite helpful. When we run a command on a terminal on Linux it generates some output of that command. Sometimes we need the output result of the commands. Today we are going to see how to save the output of the command.

Here, we'll explore all the essential steps and requirements to Save the Output of a Command in a File in Linux effectively.

How to Save Output of Command in a File in Linux?

There are multiple methods available in Linux for saving command output to a file. Some of the more popular methods are listed below:

Using Redirection Operators in Linux

We can use the redirections operators to save the output of commands into files. Redirection operators redirect the output of a command to the file instead of the output terminal.

There are two main redirection operators in Linux:

Example 1: Using the > Operator

The first operator is ">" which is used to redirect the output of a command to the file, but this operator erases all existing data in that file and overwrites the command output,

Let's see one example of > redirection operator:

How to save output of command in a file in Linux.

In the above image, we can see that the previous content of the output.txt file gets erased and the output of the ls command is written into the file.

Example 2: Using the >> Operator

Now let's see about the second redirection operator is >>. Using this operator we can append the output of the command to the file. It does not erase any previous content of the file.

Let's see the example of the>> operator.

In the above image, we can see that the output of the command is appended to the output.txt file without erasing the content stored in that file.

If the file mentioned after the Redirection operator in not exist then it will be created automatically.

Using tee command

When we use the redirection operator the output goes to the file only the redirection operator does not print it on the terminal. To see the output on the terminal and also save it into the file we can use the tee command. It sends the output of the file as well as to the terminal.

First, let's see how to use the tee operator using the pipeline. Following is the syntax of using the tee operator:

command | tee outfile.txt

Now let's see one example of the tee command:

We can see in the above image the output is redirected to the terminal as well as the output.txt file.

To append the output of the command to the file use the -a option with the tee command. Here is the syntax of the command:

command | tee outfile.txt

Now Let's see one example of this command

In this image, we can see that the output of the cowsay command is stored in the output.txt file without erasing the existing data of the file.

Conclusion

One simple but effective feature in Linux is the ability to save command output to a file. Redirecting output is a useful ability whether you're writing logs, troubleshooting, or just storing data for later use. You can collect errors, merge outputs, and append to or rewrite files based on your needs. You may improve the effectiveness and organization of your workflow by learning these strategies.