# what

## 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



           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(1p)) 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.
    


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