PROLOG

       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.

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.1‐2017, 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.1‐2017, 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\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.

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
       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.1‐2017
       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.1‐2017, 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 1003.1-2017, Standard
       for Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group  Base
       Specifications  Issue  7, 2018 Edition, Copyright (C) 2018 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 Standard, 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 .

       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                                   2017                                            WC(1POSIX)