IEEE/The Open Group
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.
what — identify SCCS files (DEVELOPMENT)
what [-s] file...
The what utility shall search the given files for all occurrences of the pattern that get (see get) substitutes for the %Z% keyword ( \(dq@(#)\(dq) and shall write to standard output what follows until the first occurrence of one of the following:
" > newline \ NUL
The what utility shall conform to the Base Definitions volume of POSIX.1-2008, 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.|
The following operands shall be supported:
|file||A pathname of a file to search.|
The input files shall be of any file type.
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.1-2008, 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.|
The standard output shall consist of the following for each file operand:
"%s:\n\t%s\n", <pathname>, <identification string>
The standard error shall be used only for diagnostic messages.
The following exit values shall be returned:
|0||Any matches were found.|
CONSEQUENCES OF ERRORS
The following sections are informative.
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 \(dq@(#)\(dq is included in a library routine in a shared library, it might not be found in an a.out file using that library routine.
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
f.c: identification information ... f.o: identification information ... a.out: identification information ...
The Base Definitions volume of POSIX.1-2008, Chapter 8, Environment Variables, Section 12.2, Utility Syntax Guidelines
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 .