WC(1P)							     POSIX Programmer's Manual							    WC(1P)

PROLOG

       This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
       ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

NAME

       wc -- word, line, and byte or character count

SYNOPSIS

       wc [-c|-m] [-lw] [file...]

DESCRIPTION

       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.

OPTIONS

       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.

OPERANDS

       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.

STDIN

       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.

INPUT FILES

       The input files may be of any type.

ENVIRONMENT VARIABLES

       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.

ASYNCHRONOUS EVENTS

       Default.

STDOUT

       By default, the standard output shall contain an entry for each input file of the form:

	   "%d %d %d %s
", <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.

STDERR

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES

       None.

EXTENDED DESCRIPTION

       None.

EXIT STATUS

       The following exit values shall be returned:

	0    Successful completion.

       >0    An error occurred.

CONSEQUENCES OF ERRORS

       Default.

       The following sections are informative.

APPLICATION USAGE

       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

EXAMPLES

       None.

RATIONALE

       The output file format pseudo-printf() string differs from the System V version of wc:

	   "%7d%7d%7d %s
"

       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 mul-
       tiple 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).

FUTURE DIRECTIONS

       None.

SEE ALSO

       cksum

       The Base Definitions volume of POSIX.1-2008, Chapter 8, Environment Variables, Section 12.2, Utility Syntax Guidelines

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technol-
       ogy -- 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 Stan-
       dard 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)