nl : number lines of files
[SYNOPSIS] nl OPTION FILE
OPTION
-b STYLE use STYLE for numbering body lines
-f STYLE use STYLE for numbering footer lines
-h STYLE use STYLE for numbering header lines
-i NUM line NUMBER increment at each line
-n FORMAT insert line numbers according to FORMAT
-s STRING add STRING after (possible) line number
-v NUM first line NUMBER for each section
-w NUM use NUMBER columns for line numbers
STYLE
a number all lines
t number only nonempty lines
n number no lines
pBRE number only lines that contain a match for the basic regular expression, BRE
FORMAT
ln left justified, no leading zeros
rn right justified, no leading zeros
rz right justified, leading zeros