What are other `nl` options?

Here are some additional options for the nl command:

1. -v NUM: Start numbering at the specified number NUM instead of the default starting value of 1.

2. -i NUM: Increment the line numbers by NUM instead of the default increment of 1.

3. -l NUM: Group NUM lines together and only number the first line of each group. This can be useful for organizing output.

4. -f a: Number all header lines (lines before the first body line). This is useful for distinguishing header information in structured files.

5. -b t: Number only non-empty lines. This option is helpful when you want to skip blank lines in the numbering.

6. -b p'PATTERN': Number lines that match a specific pattern defined by PATTERN. This allows for selective numbering based on content.

7. -s STRING: Customize the separator between the line number and the text. By default, a tab is used, but you can specify a different string.

These options provide flexibility in how you number lines in text files, allowing for various formatting and selection criteria based on your needs.