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 .