nl(C)                           19 June 1992                           nl(C)


 Name

    nl - add line numbers to a file

 Syntax

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

 Description

    The nl command 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.  Dif-
    ferent line numbering options are independently available for header,
    body, and footer (for example, no numbering of header and footer lines
    while numbering blank lines only in the body).

    The start of logical page sections is signaled by input lines containing
    nothing but one or more pairs of backslash-followed-by-colon:

    _________________________________________________________________________
    Page Section                            Line Contents
    _________________________________________________________________________
    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 filename.  Only one file may be named.  The options are:

    -b type   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).

    -h type   Same as -b type except for header.  Default type for logical
              page header is n (no lines numbered).

    -f type   Same as -b type except for footer.  Default for logical page
              footer is n (no lines numbered).

    -p        Does not restart numbering at logical page delimiters.

    -v start# start# is the initial value used to number logical page lines.
              Default is 1.

    -i incr   incr is the increment value used to number logical page lines.
              Default is 1.

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

    -w width  width is the number of characters to be used for the line num-
              ber.  Default width is 6.

    -n format format is the line numbering format.  Recognized values are:
              ln, left justified, leading zeroes suppressed; rn, right justi-
              fied, leading zeroes suppressed; rz, right justified, leading
              zeroes kept.  Default format is rn (right justified).

    -l num    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(C)

 Standards conformance

    nl is conformant with:

    AT&T SVID Issue 2;
    and X/Open Portability Guide, Issue 3, 1989.