How to display line numbers when viewing file contents?

Displaying Line Numbers When Viewing File Contents

Displaying line numbers when viewing file contents is a common task in the Linux environment, and it can be easily accomplished using various commands and tools. Here's how you can do it:

Using the cat Command with the -n Option

The cat command is a powerful tool for viewing the contents of a file. To display line numbers along with the file contents, you can use the -n option. Here's an example:

cat -n file.txt

This will output the file contents with line numbers displayed on the left-hand side.

Using the less Command with the -N Option

The less command is another popular tool for viewing file contents. It provides more advanced features, such as the ability to navigate through the file and search for specific content. To display line numbers, you can use the -N option:

less -N file.txt

This will open the file in the less pager, and the line numbers will be displayed on the left-hand side.

Using the nl Command

The nl command is specifically designed to add line numbers to the output of a file. Here's how you can use it:

nl file.txt

This will output the file contents with line numbers on the left-hand side.

Using the sed Command

The sed command is a powerful text processing tool that can be used to add line numbers to a file. Here's an example:

sed = file.txt | sed 'N;s/\n/\t/'

This command first uses the = command to add line numbers to the file, and then the sed command is used to format the output by replacing the newline character (\n) with a tab (\t).

Mermaid Diagram

Here's a Mermaid diagram that illustrates the different ways to display line numbers when viewing file contents:

In summary, there are several ways to display line numbers when viewing file contents in the Linux environment, including using the cat, less, nl, and sed commands. Each method has its own advantages and can be chosen based on your specific needs and preferences.