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       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

       what — identify SCCS files (DEVELOPMENT)

SYNOPSIS

       what [-s] file...

DESCRIPTION

       The  what utility shall search the given files for all occurrences of the pattern that get
       (see get) substitutes for the %Z% keyword ("@(#)") and shall write to standard output what
       follows until the first occurrence of one of the following:

           "   >   newline   \   NUL

OPTIONS

       The  what  utility  shall  conform to the Base Definitions volume of POSIX.1‐2017, Section
       12.2, Utility Syntax Guidelines.

       The following option shall be supported:

       -s        Quit after finding the first occurrence of the pattern in each file.

OPERANDS

       The following operands shall be supported:

       file      A pathname of a file to search.

STDIN

       Not used.

INPUT FILES

       The input files shall be of any file type.

ENVIRONMENT VARIABLES

       The following environment variables shall affect the execution of what:

       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).

       LC_MESSAGES
                 Determine the locale that should be used to affect the format  and  contents  of
                 diagnostic messages written to standard error.

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

ASYNCHRONOUS EVENTS

       Default.

STDOUT

       The standard output shall consist of the following for each file operand:

           "%s:\n\t%s\n", <pathname>, <identification string>

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     Any matches were found.

       1     Otherwise.

CONSEQUENCES OF ERRORS

       Default.

       The following sections are informative.

APPLICATION USAGE

       The  what  utility  is intended to be used in conjunction with the SCCS command get, which
       automatically inserts  identifying  information,  but  it  can  also  be  used  where  the
       information is inserted by any other means.

       When  the string "@(#)" is included in a library routine in a shared library, it might not
       be found in an a.out file using that library routine.

EXAMPLES

       If the C-language program in file f.c contains:

           char ident[] = "@(#)identification information";

       and f.c is compiled to yield f.o and a.out, then the command:

           what f.c f.o a.out

       writes:

           f.c:
               identification information
               ...
           f.o:
               identification information
               ...
           a.out:
               identification information
               ...

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       get

       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 .