nl(1)							      General Commands Manual							     nl(1)

NAME

       nl - line numbering filter

SYNOPSIS

       type] type] type] start#] incr] sep] width] format] num] delim] [file]

DESCRIPTION

       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 num-
       bered on the left in accordance with the command options in effect.

       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 delimiter character(s):
									      |
								Line contents | Start of
								--------------+----------
								   :::     |  header
								   ::       |  body
								   :	      |  footer

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

       Command options can appear in any order and can be intermingled with an optional file name.  Only one file can be  named.   recognizes  the
       following options:

	      Specifies which logical page body lines are to be numbered.
			  Recognized types and their meanings are:

			       number all lines;
			       number lines with printable text only;
			       no line numbering;
			       number only lines that contain the regular expression
					   specified in string.  Basic Regular Expression syntax is supported (see regexp(5)).

			  The default type for logical page body is (text lines numbered).

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

	      Same as	  except for footer.  Default for logical page footer is (no lines numbered).

	      Do not restart numbering at logical page delimiters.

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

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

	      sep	  is  the  character  or  characters used in separating the line number and the corresponding text line.  Default sep is a
			  tab.

	      width	  is the number of character columns to be used for the line number.  Default width is

	      format	  is the line numbering format.  Recognized values are:

			       left justified, leading zeroes
				     suppressed;
			       right justified,
				     leading zeroes suppressed;
			       right justified, leading zeroes kept.

			  Default format is (right justified).

	      num	  is the number of consecutive blank lines to be treated and numbered as a single line.  For  example,	results  in  every
			  third adjacent blank line being numbered if the appropriate and/or option is set.  Default is

	      The delimiter characters specifying the start of a logical page
			  section  can be changed from the default characters to two user-specified characters.  If only one character is entered,
			  the second character remains the default character No space should appear between the and the delimiter characters, how-
			  ever,  this  restriction  is	not there for (see standards(5)) compliant To define a backslash as the delimiter, use two
			  backslashes.

EXTERNAL INFLUENCES

       For information about the UNIX Standard environment, see standards(5).

   Environment Variables
       determines the collating sequence used in evaluating regular expressions.

       determines the characters matched by character class expressions in regular expressions.

       If or is not specified in the environment or is set to the empty string, the value of is used as a default for each  unspecified  or  empty
       variable.  If is not specified or is set to the empty string, a default of "C" (see lang(5)) is used instead of

       If  any	internationalization  variable	contains an invalid setting, behaves as if all internationalization variables are set to "C".  See
       environ(5).

   International Code Set Support
       Single-byte character code sets are supported.

EXAMPLES

       Number starting at line number 10, using an increment of ten.  The logical page delimiters are and

SEE ALSO

       pr(1), environ(5), lang(5), regexp(5), standards(5).

STANDARDS CONFORMANCE

																	     nl(1)