How can I use the nl command to display line numbers with right-zero-padding?

Using the nl Command to Display Line Numbers with Right-Zero-Padding

The nl command in Linux is a useful tool for displaying line numbers in the output of a file or command. By default, the nl command will display line numbers without any padding, but you can use the -w option to specify the width of the line number field and the -n option to control the format of the line numbers.

To display line numbers with right-zero-padding, you can use the following command:

nl -w [width] -n rz [file]

Here's how it works:

• -w [width]: Specifies the width of the line number field. For example, -w 4 will display line numbers with a width of 4 characters.
• -n rz: Specifies the line number format as "right-zero-padded". This means that the line numbers will be padded with leading zeros to maintain the specified width.
• [file]: The file you want to display with line numbers.

Here's an example:

$ cat example.txt
This is a sample text file.
It has three lines.

Without any options, the nl command will display the line numbers as follows:

$ nl example.txt
     1  This is a sample text file.
     2  It has three lines.
     3

To display the line numbers with right-zero-padding, you can use the following command:

$ nl -w 4 -n rz example.txt
0001  This is a sample text file.
0002  It has three lines.
0003

In this example, the line numbers are displayed with a width of 4 characters and are right-zero-padded, so the line numbers are displayed as "0001", "0002", and "0003".

Here's a Mermaid diagram that illustrates the key concepts:

By using the nl command with the right options, you can easily display line numbers with right-zero-padding, which can be useful for various text processing tasks, such as code formatting, document organization, and data analysis.