1WC(1P) POSIX Programmer's Manual WC(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 wc — word, line, and byte or character count
13
15 wc [-c|-m] [-lw] [file...]
16
18 The wc utility shall read one or more input files and, by default,
19 write the number of <newline> characters, words, and bytes contained in
20 each input file to the standard output.
21 The utility also shall write a total count for all named files, if more
23 than one input file is specified.
24 The wc utility shall consider a word to be a non-zero-length string of
26 characters delimited by white space.
27
29 The wc utility shall conform to the Base Definitions volume of
30 POSIX.1‐2017, Section 12.2, Utility Syntax Guidelines.
31 The following options shall be supported:
33 -c Write to the standard output the number of bytes in each
35 input file.
36 -l Write to the standard output the number of <newline> charac‐
38 ters in each input file.
39 -m Write to the standard output the number of characters in each
41 input file.
42 -w Write to the standard output the number of words in each
44 input file.
45 When any option is specified, wc shall report only the information
47 requested by the specified options.
48
50 The following operand shall be supported:
51 file A pathname of an input file. If no file operands are speci‐
53 fied, the standard input shall be used.
54
56 The standard input shall be used if no file operands are specified, and
57 shall be used if a file operand is '-' and the implementation treats
58 the '-' as meaning standard input. Otherwise, the standard input shall
59 not be used. See the INPUT FILES section.
60
62 The input files may be of any type.
63
65 The following environment variables shall affect the execution of wc:
66 LANG Provide a default value for the internationalization vari‐
68 ables that are unset or null. (See the Base Definitions vol‐
69 ume of POSIX.1‐2017, Section 8.2, Internationalization Vari‐
70 ables for the precedence of internationalization variables
71 used to determine the values of locale categories.)
72 LC_ALL If set to a non-empty string value, override the values of
74 all the other internationalization variables.
75 LC_CTYPE Determine the locale for the interpretation of sequences of
77 bytes of text data as characters (for example, single-byte as
78 opposed to multi-byte characters in arguments and input
79 files) and which characters are defined as white-space char‐
80 acters.
81 LC_MESSAGES
83 Determine the locale that should be used to affect the format
84 and contents of diagnostic messages written to standard error
85 and informative messages written to standard output.
86 NLSPATH Determine the location of message catalogs for the processing
88 of LC_MESSAGES.
89
91 Default.
92
94 By default, the standard output shall contain an entry for each input
95 file of the form:
96 "%d %d %d %s\n", <newlines>, <words>, <bytes>, <file>
99 If the -m option is specified, the number of characters shall replace
101 the <bytes> field in this format.
102 If any options are specified and the -l option is not specified, the
104 number of <newline> characters shall not be written.
105 If any options are specified and the -w option is not specified, the
107 number of words shall not be written.
108 If any options are specified and neither -c nor -m is specified, the
110 number of bytes or characters shall not be written.
111 If no input file operands are specified, no name shall be written and
113 no <blank> characters preceding the pathname shall be written.
114 If more than one input file operand is specified, an additional line
116 shall be written, of the same format as the other lines, except that
117 the word total (in the POSIX locale) shall be written instead of a
118 pathname and the total of each column shall be written as appropriate.
119 Such an additional line, if any, is written at the end of the output.
120
122 The standard error shall be used only for diagnostic messages.
123
125 None.
126
128 None.
129
131 The following exit values shall be returned:
132 0 Successful completion.
134 >0 An error occurred.
136
138 Default.
139 The following sections are informative.
141
143 The -m option is not a switch, but an option at the same level as -c.
144 Thus, to produce the full default output with character counts instead
145 of bytes, the command required is:
146 wc -mlw
149
151 None.
152
154 The output file format pseudo-printf() string differs from the System V
155 version of wc:
156 "%7d%7d%7d %s\n"
159 which produces possibly ambiguous and unparsable results for very large
161 files, as it assumes no number shall exceed six digits.
162 Some historical implementations use only <space>, <tab>, and <newline>
164 as word separators. The equivalent of the ISO C standard isspace()
165 function is more appropriate.
166 The -c option stands for ``character'' count, even though it counts
168 bytes. This stems from the sometimes erroneous historical view that
169 bytes and characters are the same size. Due to international require‐
170 ments, the -m option (reminiscent of ``multi-byte'') was added to
171 obtain actual character counts.
172 Early proposals only specified the results when input files were text
174 files. The current specification more closely matches historical prac‐
175 tice. (Bytes, words, and <newline> characters are counted separately
176 and the results are written when an end-of-file is detected.)
177 Historical implementations of the wc utility only accepted one argument
179 to specify the options -c, -l, and -w. Some of them also had multiple
180 occurrences of an option cause the corresponding count to be written
181 multiple times and had the order of specification of the options affect
182 the order of the fields on output, but did not document either of
183 these. Because common usage either specifies no options or only one
184 option, and because none of this was documented, the changes required
185 by this volume of POSIX.1‐2017 should not break many historical appli‐
186 cations (and do not break any historical conforming applications).
187
189 None.
190
192 cksum
193 The Base Definitions volume of POSIX.1‐2017, Chapter 8, Environment
195 Variables, Section 12.2, Utility Syntax Guidelines
196
198 Portions of this text are reprinted and reproduced in electronic form
199 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
200 table Operating System Interface (POSIX), The Open Group Base Specifi‐
201 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
202 Electrical and Electronics Engineers, Inc and The Open Group. In the
203 event of any discrepancy between this version and the original IEEE and
204 The Open Group Standard, the original IEEE and The Open Group Standard
205 is the referee document. The original Standard can be obtained online
206 at http://www.opengroup.org/unix/online.html .
207 Any typographical or formatting errors that appear in this page are
209 most likely to have been introduced during the conversion of the source
210 files to man page format. To report such errors, see https://www.ker‐
211 nel.org/doc/man-pages/reporting_bugs.html .
212IEEE/The Open Group 2017 WC(1P)