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This article focuses on "how to use the redirect operator and tee command to write text to a file in Bash", interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Let's let the editor learn how to write text to a file in Bash using the redirect operator and the tee command.

Write to a file using the redirect operator

In Bash, the redirection of output allows you to capture the output of a command and write it to a file.

The general format for redirecting and writing output to a file is as follows:

Output > filename output > > filename

The redirect operator writes the output to the given file. If the file exists, it will be truncated to zero length. Otherwise, a file is created. Be careful when using this operator, as you may overwrite an important file.

> > the redirect operator appends the output to the specified file. If the file does not exist, it is created.

You need to have write access to the file. Otherwise, you will receive an error in which permissions are denied.

This is a simple example that shows how to redirect the output of the echo command to a file:

Linuxmi@linuxmi:~$ echo "welcome to www.linuxmi.com" > linuxmi.txt

To prevent existing files from being overwritten, use the set built-in feature to enable the "noclobber" option:

Linuxmi@linuxmi:~$ set-o noclobber linuxmi@linuxmi:~$ echo "welcome to www.linuxmi.com" > linuxmi.txt

The output is as follows:

Bash: linuxmi.txt: cannot overwrite an existing file

> | operator allows you to override the "noclobber" option of Bash:

Linuxmi@linuxmi:~$ set-o noclobber linuxmi@linuxmi:~$ echo "welcome to www.linuxmi.com" > | linuxmi.txt

The > > operator appends the output to the end of the file instead of overwriting the file:

Linuxmi@linuxmi:~$ echo "welcome to www.linuxmi.com" > > linuxmi.txt

Use the printf command to create a complex output:

Printf "Hello, Isimm% s.\ n" $USER > Linuxmi.com.txt

If you want to write multiple lines to a file, refer to Here document (Heredoc) redirection.

For example, you can pass the content to the cat command and write it to a file:

Cat linuxmi.com.txt

The current working directory is: $PWD

You log in to $(whoami) as:

EOF

To attach these lines, use > > modify > before the file name:

Cat > linuxmi.txt

The current working directory is: $PWD

You log in to $(whoami) as:

EOF

You can write the output of any command to a file:

Linuxmi@linuxmi:~$ date + "Year:% Y, Month:% m, Day:% d" > xxvi.txt

The output of the date command is written to the file.

Use the tee command to write a file

The tee command reads data from standard input and writes data to both standard output and one or more files.

Linuxmi@linuxmi:~$ echo "welcome to www.linuxmi.com" | tee linuxmi.txt

The default behavior of this tee command is to overwrite the specified file, the same as the > operator. To attach the output to a file, invoke the command using the-a (--append) option:

Linuxmi@linuxmi:~$ echo "welcome to www.linuxmi.com" | tee-a linuxmi.com.txt

If you do not want tee to write to standard output, you can redirect it to / dev/null:

Linuxmi@linuxmi:~$ echo "welcome to www.linuxmi.com" | tee www.linuxmi.com.txt > / dev/null

To write text to multiple files, specify the file as an argument to the tee command:

Linuxmi@linuxmi:~$ echo "welcome to www.linuxmi.com" | tee file_1.txt file_2.txt file_3.txt

Another advantage of this tee command is that you can use it with and write to files owned by other sudo users. To append text to a file that you do not have write permission to, ask sudo to precede it with tee:

Linuxmi@linuxmi:~$ echo "welcome to www.linuxmi.com" | sudo tee linuxmi.txt

The output of the echo command is passed as input to tee, and tee elevates sudo privileges and writes text to the file.

Summary

In Linux, to write text to a file, use the > and > > redirection operators or the tee command.

At this point, I believe you have a better understanding of "how to write text to a file in Bash using the redirect operator and the tee command." you might as well do it in practice! Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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