1NL(1P) POSIX Programmer's Manual NL(1P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 nl - line numbering filter
13
15 nl [-p][-b type][-d delim][-f type][-h type][-i incr][-l num][-n for‐
16 mat]
17 [-s sep][-v startnum][-w width][file]
18
20 The nl utility shall read lines from the named file or the standard
21 input if no file is named and shall reproduce the lines to standard
22 output. Lines shall be numbered on the left. Additional functionality
23 may be provided in accordance with the command options in effect.
24 The nl utility views the text it reads in terms of logical pages. Line
26 numbering shall be reset at the start of each logical page. A logical
27 page consists of a header, a body, and a footer section. Empty sections
28 are valid. Different line numbering options are independently available
29 for header, body, and footer (for example, no numbering of header and
30 footer lines while numbering blank lines only in the body).
31 The starts of logical page sections shall be signaled by input lines
33 containing nothing but the following delimiter characters:
34 Line Start of
36 \:\:\: Header
37 \:\: Body
38 \: Footer
39 Unless otherwise specified, nl shall assume the text being read is in a
41 single logical page body.
42
44 The nl utility shall conform to the Base Definitions volume of
45 IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines. Only
46 one file can be named.
47 The following options shall be supported:
49 -b type
51 Specify which logical page body lines shall be numbered. Recog‐
52 nized types and their meaning are:
53 a
55 Number all lines.
56 t
58 Number only non-empty lines.
59 n
61 No line numbering.
62 pstring
64 Number only lines that contain the basic regular expression
65 specified in string.
66 The default type for logical page body shall be t (text lines num‐
69 bered).
70 -d delim
72 Specify the delimiter characters that indicate the start of a
73 logical page section. These can be changed from the default
74 characters "\:" to two user-specified characters. If only one
75 character is entered, the second character shall remain the
76 default character ':' .
77 -f type
79 Specify the same as b type except for footer. The default for
80 logical page footer shall be n (no lines numbered).
81 -h type
83 Specify the same as b type except for header. The default type
84 for logical page header shall be n (no lines numbered).
85 -i incr
87 Specify the increment value used to number logical page lines.
88 The default shall be 1.
89 -l num
91 Specify the number of blank lines to be considered as one. For
92 example, -l 2 results in only the second adjacent blank line
93 being numbered (if the appropriate -h a, -b a, or -f a option is
94 set). The default shall be 1.
95 -n format
97 Specify the line numbering format. Recognized values are: ln,
98 left justified, leading zeros suppressed; rn, right justified,
99 leading zeros suppressed; rz, right justified, leading zeros
100 kept. The default format shall be rn (right justified).
101 -p Specify that numbering should not be restarted at logical page
103 delimiters.
104 -s sep
106 Specify the characters used in separating the line number and
107 the corresponding text line. The default sep shall be a <tab>.
108 -v startnum
110 Specify the initial value used to number logical page lines. The
111 default shall be 1.
112 -w width
114 Specify the number of characters to be used for the line number.
115 The default width shall be 6.
116
119 The following operand shall be supported:
120 file A pathname of a text file to be line-numbered.
122
125 The standard input is a text file that is used if no file operand is
126 given.
127
129 The input file named by the file operand is a text file.
130
132 The following environment variables shall affect the execution of nl:
133 LANG Provide a default value for the internationalization variables
135 that are unset or null. (See the Base Definitions volume of
136 IEEE Std 1003.1-2001, Section 8.2, Internationalization Vari‐
137 ables for the precedence of internationalization variables used
138 to determine the values of locale categories.)
139 LC_ALL If set to a non-empty string value, override the values of all
141 the other internationalization variables.
142 LC_COLLATE
144 Determine the locale for the behavior of ranges, equivalence
146 classes, and multi-character collating elements within regular
147 expressions.
148 LC_CTYPE
150 Determine the locale for the interpretation of sequences of
151 bytes of text data as characters (for example, single-byte as
152 opposed to multi-byte characters in arguments and input files),
153 the behavior of character classes within regular expressions,
154 and for deciding which characters are in character class graph
155 (for the -b t, -f t, and -h t options).
156 LC_MESSAGES
158 Determine the locale that should be used to affect the format
159 and contents of diagnostic messages written to standard error.
160 NLSPATH
162 Determine the location of message catalogs for the processing of
163 LC_MESSAGES .
164
167 Default.
168
170 The standard output shall be a text file in the following format:
171 "%s%s%s", <line number>, <separator>, <input line>
174 where <line number> is one of the following numeric formats:
176 %6d When the rn format is used (the default; see -n).
178 %06d When the rz format is used.
180 %-6d When the ln format is used.
182 <empty>
184 When line numbers are suppressed for a portion of the page; the
185 <separator> is also suppressed.
186 In the preceding list, the number 6 is the default width; the -w option
189 can change this value.
190
192 The standard error shall be used only for diagnostic messages.
193
195 None.
196
198 None.
199
201 The following exit values shall be returned:
202 0 Successful completion.
204 >0 An error occurred.
206
209 Default.
210 The following sections are informative.
212
214 In using the -d delim option, care should be taken to escape characters
215 that have special meaning to the command interpreter.
216
218 The command:
219 nl -v 10 -i 10 -d \!+ file1
222 numbers file1 starting at line number 10 with an increment of 10. The
224 logical page delimiter is "!+" . Note that the '!' has to be escaped
225 when using csh as a command interpreter because of its history substi‐
226 tution syntax. For ksh and sh the escape is not necessary, but does not
227 do any harm.
228
230 None.
231
233 None.
234
236 pr
237
239 Portions of this text are reprinted and reproduced in electronic form
240 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
241 -- Portable Operating System Interface (POSIX), The Open Group Base
242 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
243 Electrical and Electronics Engineers, Inc and The Open Group. In the
244 event of any discrepancy between this version and the original IEEE and
245 The Open Group Standard, the original IEEE and The Open Group Standard
246 is the referee document. The original Standard can be obtained online
247 at http://www.opengroup.org/unix/online.html .
248IEEE/The Open Group 2003 NL(1P)