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PROLOG | NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OPERANDS | STDIN | INPUT FILES | ENVIRONMENT VARIABLES | ASYNCHRONOUS EVENTS | STDOUT | STDERR | OUTPUT FILES | EXTENDED DESCRIPTION | EXIT STATUS | CONSEQUENCES OF ERRORS | APPLICATION USAGE | EXAMPLES | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT |
WC(1P) POSIX Programmer's Manual WC(1P)
This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior), or
the interface may not be implemented on Linux.
wc — word, line, and byte or character count
wc [−c|−m] [−lw] [file...]
The wc utility shall read one or more input files and, by default,
write the number of <newline> characters, words, and bytes contained
in each input file to the standard output.
The utility also shall write a total count for all named files, if
more than one input file is specified.
The wc utility shall consider a word to be a non-zero-length string
of characters delimited by white space.
The wc utility shall conform to the Base Definitions volume of
POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines.
The following options shall be supported:
−c Write to the standard output the number of bytes in each
input file.
−l Write to the standard output the number of <newline>
characters in each input file.
−m Write to the standard output the number of characters in
each input file.
−w Write to the standard output the number of words in each
input file.
When any option is specified, wc shall report only the information
requested by the specified options.
The following operand shall be supported:
file A pathname of an input file. If no file operands are
specified, the standard input shall be used.
The standard input shall be used if no file operands are specified,
and shall be used if a file operand is '−' and the implementation
treats the '−' as meaning standard input. Otherwise, the standard
input shall not be used. See the INPUT FILES section.
The input files may be of any type.
The following environment variables shall affect the execution of wc:
LANG Provide a default value for the internationalization
variables that are unset or null. (See the Base Definitions
volume of POSIX.1‐2008, 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_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) and which characters are defined as white-space
characters.
LC_MESSAGES
Determine the locale that should be used to affect the
format and contents of diagnostic messages written to
standard error and informative messages written to standard
output.
NLSPATH Determine the location of message catalogs for the
processing of LC_MESSAGES.
Default.
By default, the standard output shall contain an entry for each input
file of the form:
"%d %d %d %s\n", <newlines>, <words>, <bytes>, <file>
If the −m option is specified, the number of characters shall replace
the <bytes> field in this format.
If any options are specified and the −l option is not specified, the
number of <newline> characters shall not be written.
If any options are specified and the −w option is not specified, the
number of words shall not be written.
If any options are specified and neither −c nor −m is specified, the
number of bytes or characters shall not be written.
If no input file operands are specified, no name shall be written and
no <blank> characters preceding the pathname shall be written.
If more than one input file operand is specified, an additional line
shall be written, of the same format as the other lines, except that
the word total (in the POSIX locale) shall be written instead of a
pathname and the total of each column shall be written as
appropriate. Such an additional line, if any, is written at the end
of the output.
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.
The −m option is not a switch, but an option at the same level as −c.
Thus, to produce the full default output with character counts
instead of bytes, the command required is:
wc −mlw
None.
The output file format pseudo-printf() string differs from the System
V version of wc:
"%7d%7d%7d %s\n"
which produces possibly ambiguous and unparsable results for very
large files, as it assumes no number shall exceed six digits.
Some historical implementations use only <space>, <tab>, and
<newline> as word separators. The equivalent of the ISO C standard
isspace() function is more appropriate.
The −c option stands for ``character'' count, even though it counts
bytes. This stems from the sometimes erroneous historical view that
bytes and characters are the same size. Due to international
requirements, the −m option (reminiscent of ``multi-byte'') was added
to obtain actual character counts.
Early proposals only specified the results when input files were text
files. The current specification more closely matches historical
practice. (Bytes, words, and <newline> characters are counted
separately and the results are written when an end-of-file is
detected.)
Historical implementations of the wc utility only accepted one
argument to specify the options −c, −l, and −w. Some of them also
had multiple occurrences of an option cause the corresponding count
to be written multiple times and had the order of specification of
the options affect the order of the fields on output, but did not
document either of these. Because common usage either specifies no
options or only one option, and because none of this was documented,
the changes required by this volume of POSIX.1‐2008 should not break
many historical applications (and do not break any historical
conforming applications).
None.
cksum(1p)
The Base Definitions volume of POSIX.1‐2008, Chapter 8, Environment
Variables, Section 12.2, Utility Syntax Guidelines
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) 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.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the
source files to man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 WC(1P)