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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 dif-
       fer (consult the corresponding 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>s, 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 IEEE Std 1003.1-2001, Section 12.2, Utility Syn-
       tax 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>s 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 only if no file operands are specified. 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 IEEE Std 1003.1-2001, Section 8.2, Internationalization Variables for  the  prece-
              dence 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  exam-
              ple,  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  writ-
              ten 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\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>s 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>s 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\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  erro-
       neous  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>s 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 IEEE Std 1003.1-2001 should not break  many
       historical applications (and do not break any historical conforming applications).

FUTURE DIRECTIONS
       None.

SEE ALSO
       cksum

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Stan-
       dard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base  Specifica-
       tions  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 Stan-
       dard,  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 .



IEEE/The Open Group                  2003                               WC(1P)