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NL(1)                       General Commands Manual                      NL(1)

     nl - line numbering filter

     nl [-p] [-b type] [-d delim] [-f type] [-h type] [-i incr] [-l num]
        [-n format] [-s sep] [-v startnum] [-w width] [file]

     The nl utility reads lines from the named file, applies a configurable
     line numbering filter operation, and writes the result to the standard
     output.  If file is a single dash (`-') or absent, nl reads from the
     standard input.

     The nl utility treats the text it reads in terms of logical pages.
     Unless specified otherwise, 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 sections.

     The starts of logical page sections are signaled by input lines
     containing nothing but one of the following sequences of delimiter

           Line       Start of
           \:\:\:     header
           \:\:       body
           \:         footer

     If the input does not contain any logical page section signaling
     directives, the text being read is assumed to consist of a single logical
     page body.

     The following options are available:

     -b type
             Specify the logical page body lines to be numbered.  Recognized
             type arguments are:

             a          Number all lines.

             t          Number only non-empty lines.

             n          No line numbering.

             pexpr      Number only those lines that contain the basic regular
                        expression specified by expr.

             The default type for logical page body lines is t.

     -d delim
             Specify the delimiter characters used to indicate the start of a
             logical page section in the input file.  At most two characters
             may be specified; if only one character is specified, the first
             character is replaced and the second character remains unchanged.
             The default delim characters are ``\:''.

     -f type
             Specify the same as -b type except for logical page footer lines.
             The default type for logical page footer lines is n.

     -h type
             Specify the same as -b type except for logical page header lines.
             The default type for logical page header lines is n.

     -i incr
             Specify the increment value used to number logical page lines.
             The default incr value is 1.

     -l num  If numbering of all lines is specified for the current logical
             section using the corresponding -b a, -f a or -h a option,
             specify the number of adjacent blank lines to be considered as
             one.  For example, -l 2 results in only the second adjacent blank
             line being numbered.  The default num value is 1.

     -n format
             Specify the line numbering output format.  Recognized format
             arguments are:

                   ln    Left justified.
                   rn    Right justified, leading zeros suppressed.
                   rz    Right justified, leading zeros kept.

             The default format is rn.

     -p      Specify that line numbering should not be restarted at logical
             page delimiters.

     -s sep  Specify the characters used in separating the line number and the
             corresponding text line.  The default sep setting is a single tab

     -v startnum
             Specify the initial value used to number logical page lines; see
             also the description of the -p option.  The default startnum
             value is 1.

     -w width
             Specify the number of characters to be occupied by the line
             number; if the width is insufficient to hold the line number, it
             will be truncated to its width least significant digits.  The
             default width is 6.

     The nl utility exits 0 on success, and >0 if an error occurs.


     The nl utility is compliant with the X/Open Portability Guide Issue 4,
     Version 2 ("XPG4.2") specification.

     The nl utility first appeared in AT&T System V Release 2 UNIX.

NetBSD 9.99                       May 1, 2013                      NetBSD 9.99