nl

Number lines from a file or from stdin. More information: https://manned.org/nl.

• Number non-blank lines in a file:

nl {{path/to/file}}

• Read from stdin:

{{command}} | nl

• Number [a]ll body lines including blank lines or do [n]ot number body lines:

nl {{[-b|--body-numbering]}} {{a|n}} {{path/to/file}}

• Number only the body lines that match a basic regex (BRE) [p]attern:

nl {{[-b|--body-numbering]}} p'FooBar[0-9]' {{path/to/file}}

• Use a specific increment for line numbering:

nl {{[-i|--line-increment]}} {{increment}} {{path/to/file}}

• Specify the line numbering format to [r]ight or [l]eft justified, keeping leading [z]eros or [n]ot:

nl {{[-n|--number-format]}} {{rz|ln|rn}}

• Specify the line numbering’s width (6 by default):

nl {{[-w|--number-width]}} {{col_width}} {{path/to/file}}

• Use a specific string to separate the line numbers from the lines (TAB by default):

nl {{[-s|--number-separator]}} {{separator}} {{path/to/file}}