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fmt – Optimize processing and output after reading a file

The fmt command in Linux is used to optimize the processing and output of text files after reading them. The command is used to format text files into a specified width, making them more readable and presentable. The fmt command is commonly used in Linux systems to format text files before printing or sending them as emails.

Overview

The fmt command is used to format text files into a specified width, making them more readable and presentable. The command reads the input file and formats it to the specified width, which is usually 72 characters by default. The formatted output is then written to the standard output.

Here is the basic syntax for using the fmt command:

fmt [options] [file]

The file argument is the name of the file that you want to format. If you do not specify a file, the fmt command reads from the standard input.

Here is an example of how to use the fmt command:

fmt -w 80 myfile.txt

In this example, the fmt command is used to format the file myfile.txt to a width of 80 characters.

The fmt command can also be used to format text that is piped into it from another command. For example, you can use the echo command to pipe text into the fmt command like this:

echo "This is some text that needs formatting." | fmt

This will format the text to the default width of 72 characters.

Options

The fmt command comes with a few options that you can use to customize its behavior. Here is a table of the available options:

Option Description
-w Specifies the width of the output.
-s Splits long lines into multiple lines.
-t Preserves existing tabs.
-u Disables underlining of text.
-c Centers the output.
-p Preserves leading spaces.
-h Ignores hyphenation.
-n Does not split words.

Troubleshooting tips

If you are having issues with the fmt command, here are a few troubleshooting tips:

  • Make sure that you are using the correct syntax for the command.
  • Check the permissions of the file that you are trying to format. You may need to use the sudo command to run the fmt command with elevated privileges.
  • If you are piping text into the fmt command, make sure that the text is properly formatted and does not contain any special characters that could cause issues.

Notes

  • The fmt command is commonly used in Linux systems to format text files before printing or sending them as emails.
  • The default width of the fmt command is 72 characters.
  • The fmt command can be used to format text that is piped into it from another command.

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