This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       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.

       Default.

       Default.

       Thefollowingsectionsareinformative.

       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                                          WHAT(1POSIX)

       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

       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, Section8.2, InternationalizationVariables  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.

       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
               ...

       The following exit values shall be returned:

       0     Any matches were found.

       1     Otherwise.

       None.

       None.

       The input files shall be of any file type.

       what — identify SCCS files (DEVELOPMENT)

       The following operands shall be supported:

       file      A pathname of a file to search.

       The  what  utility  shall  conform  to the Base Definitions volume of POSIX.1‐2017, Section12.2, UtilitySyntaxGuidelines.

       The following option shall be supported:

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

       None.

       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.

       None.

get

       The Base Definitions volume of POSIX.1‐2017, Chapter8,  EnvironmentVariables,  Section12.2,  UtilitySyntaxGuidelines

       The standard error shall be used only for diagnostic messages.

       Not used.

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

           "%s:\n\t%s\n", <pathname>, <identificationstring>

       what [-s]file...