User Commands  - what (1)

NAME
what(1f) - [DEVELOPER] extract SCCS-style metadata from a file (LICENSE:PD)

CONTENTS

Synopsis
Description
Options
Examples
Exit Status
Environment Variables
Author
License
See Also
Bugs

SYNOPSIS
what [ filename(s) [ -s] [ -q] [ -html|-table] ] | [ [ -help] [ -version] ]

DESCRIPTION
The what(1) utility searches each filename for occurrences of the SCCS identification string @### and prints what follows up to a ",>,\, or any non-printable ASCII character(NULL,NEWLINE,TAB,.....).

This allows files to quickly be scanned for metadata such as simple descriptions, versions and pedigree placed in the files.

OPTIONS
The following options are supported:
-single, -s
  Stops after the first occurrence of the pattern in each file.
--html, -H
  Print output as a table in an HTML document.
--table, -t
  Print output as a HTML table.
--verbose, -q
  Quiet mode (do not report errors when opening filenames)
--help, -h
  Print description of this program.
--version, -v
  Print version information for this program

EXAMPLES
Example 1: Extracting SCCS version information

Text files are generally easy to place a @### string into by using the appropriate format for a comment in the language being used. Exactly how to place a string into an object file or executable may vary depending on your compiler or optimization level. Generally the following strings will work:

o C/C++ #ident "@###identification info"
o C: char sccsid[] = "@###identification info" /* must be global scope or optimization usually removes it */
o C++: #pragma ident "@###identification info" /* many references say this should work, but unreliable */
o Fortran: character(len=*),parameter::sccsid= @###identification info be careful it is not removed by high optimization levels

For example, if program.f90 were compiled to yield program.o and executable a.out, the command: what program.f90 program.o a.out should produce: 

        program.f90:
              identification info
        program.o:
              identification info
        a.out:
              identification info
A few tips for common interpreted file types:
o shell script: #@###identification info
o HTML: <!--"@###identification info"-->

EXIT STATUS
The following exit values are returned:
0 Any matches were found.
1 No matches found.

ENVIRONMENT VARIABLES

AUTHOR
John S. Urban

LICENSE
Public Domain

SEE ALSO
The following commands can help identify file contents file(1), strings(1), nm(1), ldd(1), cpp(1), fpp(1), ident(1), ar(1), objdump(1), ranlib(1), [if SCCS installed ] sccs(1), sccs-admin(1), sccs-get(1), ...

Related topics: schema, IDL (Information Description Language), ...

BUGS
There is a remote possibility that a spurious occurrence of the "@###" pattern could be found by what(1).

If standard input is processed it must be a text file with line width less than 4,096 characters or errors may occur.

The length of the file arguments may be limited depending on what command-line argument parser is used.

Nemo Release 3.1 what (1) February 23, 2025
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