Format Text Lines with Fmt

The fmt command is a simple yet powerful utility found on Unix-like operating systems. Its primary purpose is to reformat and format text paragraphs. It reads text from standard input or files and writes the formatted text to standard output. This tool is particularly useful for tidying up text files, ensuring consistent line lengths, and improving readability, especially in command-line interfaces or when preparing text for display.

How to Use Fmt for Text Formatting

The fmt command works by reflowing text to fit a specified line width. By default, it uses a line width of 75 characters. You can easily adjust this width using the -w option, followed by the desired number of characters. This is invaluable for making long lines more manageable.

Example: Setting Line Width to 50 Characters

To format a file, ensuring that each line does not exceed 50 characters, you can pipe the file's content to the fmt command:

cat <file> | fmt -w 50

In this example:

• cat <file> reads the content of the specified file.
• The pipe symbol (|) sends the output of cat as input to the fmt command.
• fmt -w 50 reformats the input text, breaking lines to a maximum width of 50 characters.

Understanding Fmt Command Options

While the -w option is the most commonly used, fmt offers other functionalities:

• Indentation: fmt can also handle indentation, preserving existing indentation levels or applying new ones, which is crucial for code snippets or structured text.
• Paragraphs: It intelligently recognizes paragraphs, typically separated by blank lines, and reformats them independently.

Benefits of Using Fmt

Using the fmt command offers several advantages for developers and system administrators:

• Readability: Enhances the readability of text files, logs, and documentation.
• Consistency: Ensures a uniform line width across different text sources.
• Efficiency: A quick and efficient way to format text directly from the command line.

For more detailed information on the fmt command and its various options, you can refer to the official documentation or use the man fmt command in your terminal.

Explore other developer tools on our platform to streamline your workflow.