Originální popis anglicky:
nl - line numbering filter
Návod, kniha: POSIX Programmer's Manual
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 shall read lines from the named
file or the
standard input if no
file is named and shall reproduce the lines to
standard output. Lines shall be numbered on the left. Additional functionality
may be provided in accordance with the command options in effect.
The
nl utility views the text it reads in terms of logical pages. Line
numbering shall be 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 (for example, no numbering of header and footer lines while
numbering blank lines only in the body).
The starts of logical page sections shall be signaled by input lines containing
nothing but the following delimiter characters:
| Line |
Start of |
| \:\:\: |
Header |
| \:\: |
Body |
| \: |
Footer |
Unless otherwise specified,
nl shall assume the text being read is in a
single logical page body.
The
nl utility shall conform to the Base Definitions volume of
IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
Only one file can be named.
The following options shall be supported:
- -b type
- Specify which logical page body lines shall be numbered.
Recognized types and their meaning are:
- a
Number all lines.
- t
Number only non-empty lines.
- n
No line numbering.
- pstring
Number only lines that contain the basic
regular expression specified in string.
The default
type for logical page body shall be
t (text lines
numbered).
- -d delim
- Specify the delimiter characters that indicate the start of
a logical page section. These can be changed from the default characters
"\:" to two user-specified characters. If only one
character is entered, the second character shall remain the default
character ':' .
- -f type
- Specify the same as b type except for footer.
The default for logical page footer shall be n (no lines
numbered).
- -h type
- Specify the same as b type except for header.
The default type for logical page header shall be n (no
lines numbered).
- -i incr
- Specify the increment value used to number logical page
lines. The default shall be 1.
- -l num
- Specify the number of blank lines to be considered as one.
For example, -l 2 results in only the second adjacent blank
line being numbered (if the appropriate -h a,
-b a, or -f a option is set). The default
shall be 1.
- -n format
- Specify the line numbering format. Recognized values are:
ln, left justified, leading zeros suppressed; rn, right
justified, leading zeros suppressed; rz, right justified, leading
zeros kept. The default format shall be rn (right
justified).
- -p
- Specify that 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 shall be a
<tab>.
- -v startnum
- Specify the initial value used to number logical page
lines. The default shall be 1.
- -w width
- Specify the number of characters to be used for the line
number. The default width shall be 6.
The following operand shall be supported:
- file
- A pathname of a text file to be line-numbered.
The standard input is a text file that is used if no
file operand is
given.
The input file named by the
file operand is a text file.
The following environment variables shall affect the execution of
nl:
- LANG
- Provide a default value for the internationalization
variables that are unset or null. (See the Base Definitions volume of
IEEE Std 1003.1-2001, Section 8.2, Internationalization
Variables for the precedence of internationalization variables used to
determine the values of locale categories.)
- LC_ALL
- If set to a non-empty string value, override the values of
all the other internationalization variables.
- LC_COLLATE
-
Determine the locale for the behavior of ranges, equivalence classes, and
multi-character collating elements within regular expressions.
- LC_CTYPE
- Determine the locale for the interpretation of sequences of
bytes of text data as characters (for example, single-byte as opposed to
multi-byte characters in arguments and input files), the behavior of
character classes within regular expressions, and for deciding which
characters are in character class graph (for the
-b t, -f t, and -h t
options).
- LC_MESSAGES
- Determine the locale that should be used to affect the
format and contents of diagnostic messages written to standard error.
- NLSPATH
- Determine the location of message catalogs for the
processing of LC_MESSAGES .
Default.
The standard output shall be a text file in the following format:
"%s%s%s", <line number>, <separator>, <input line>
where <
line number> is one of the following numeric
formats:
- %6d
- When the rn format is used (the default; see
-n).
- %06d
- When the rz format is used.
- %-6d
- When the ln format is used.
- <empty>
- When line numbers are suppressed for a portion of the page;
the < separator> is also suppressed.
In the preceding list, the number 6 is the default width; the
-w option
can change this value.
The standard error shall be used only for diagnostic messages.
None.
None.
The following exit values shall be returned:
- 0
- Successful completion.
- >0
- An error occurred.
Default.
The following sections are informative.
In using the
-d delim option, care should be taken to escape
characters that have special meaning to the command interpreter.
The command:
nl -v 10 -i 10 -d \!+ file1
numbers
file1 starting at line number 10 with an increment of 10. The
logical page delimiter is
"!+" . Note that the
'!' has
to be escaped when using
csh as a command interpreter because of its
history substitution syntax. For
ksh and
sh the escape is not
necessary, but does not do any harm.
None.
None.
pr
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html
.
