NAME

nl − line numbering filter

SYNOPSIS

nl [−htype] [−btype] [−ftype] [−vstart#] [−iincr] [−p] [−lnum] [−ssep] [−wwidth] [−nformat] file

DESCRIPTION

Nl reads lines from the named file or the standard input if no file is named and reproduces the lines on the standard output.  Lines are numbered on the left in accordance with the command options in effect. 

Nl views the text it reads in terms of logical pages.  Line numbering is reset at the start of each logical page.  A logical page consists of a header, a body, and a footer section.  Empty sections are valid.  Different line numbering options are independently available for header, body, and footer (e.g. no numbering of header and footer lines while numbering blank lines only in the body). 

The start of logical page sections are signaled by input lines containing nothing but the following character(s):

Line contents Start of

\:\:\: header

\:\: body

\: footer

Unless signaled otherwise, nl assumes the text being read is in a single logical page body. 

Command options may appear in any order and may be intermingled with an optional file name.  Only one file may be named.  The options are:

−btype Specifies which logical page body lines are to be numbered.  Recognized types and their meaning are: a, number all lines; t, number lines with printable text only; n, no line numbering; pstring, number only lines that contain the regular expression specified in string. Default type for logical page body is t (text lines numbered). 

−htype Same as −btype except for header.  Default type for logical page header is n (no lines numbered). 

−ftype Same as −btype except for footer.  Default for logical page footer is n (no lines numbered). 

−p Do not restart numbering at logical page delimiters. 

−vstart# Start# is the initial value used to number logical page lines.  Default is 1. 

−iincr Incr is the increment value used to number logical page lines.  Default is 1. 

−ssep Sep is the character(s) used in separating the line number and the corresponding text line.  Default sep is a tab. 

−wwidth Width is the number of characters to be used for the line number.  Default width is 6. 

−nformat Format is the line numbering format.  Recognized values are: ln, left justified, leading zeroes supressed; rn, right justified, leading zeroes supressed; rz, right justified, leading zeroes kept.  Default format is rn (right justified). 

−lnum Num is the number of blank lines to be considered as one.  For example, −l2 results in only the second adjacent blank being numbered (if the appropriate −ha, −ba, and/or −fa option is set).  Default is 1. 

SEE ALSO

pr(1). 

May 16, 1980