nl
Number lines from a file or from stdin.
More information: https://manned.org/nl.1p.
- Number non-blank lines in a file:
nl path/to/file
- Read from
stdin:
command | nl -
- Number [a]ll [b]ody lines including blank lines or do [n]ot number [b]ody lines:
nl -b a|n path/to/file
- Number only the [b]ody lines that match a basic regular expression (BRE) [p]attern:
nl -b p'FooBar[0-9]' path/to/file
- Use a specific [i]ncrement for line numbering:
nl -i 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 rz|ln|rn
- Specify the line numbering's [w]idth (6 by default):
nl -w col_width path/to/file
- Use a specific string to [s]eparate the line numbers from the lines (TAB by default):
nl -s separator path/to/file