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.1‐2017, 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         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

       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.

                 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.



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

       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 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



SEE ALSO         top


       The Base Definitions volume of POSIX.1‐2017, 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 1003.1-2017, 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(1P)