wc(1p) — Linux manual page


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

PROLOG         top

       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         top

       wc — word, line, and byte or character count

SYNOPSIS         top

       wc [−c|−m] [−lw] [file...]

DESCRIPTION         top

       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         top

       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         top

       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         top

       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         top

       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

       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

                 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

       NLSPATH   Determine the location of message catalogs for the
                 processing of LC_MESSAGES.



STDOUT         top

       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         top

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES         top




EXIT STATUS         top

       The following exit values shall be returned:

        0    Successful completion.

       >0    An error occurred.



       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

EXAMPLES         top


RATIONALE         top

       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

       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).



SEE ALSO         top


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

COPYRIGHT         top

       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)