	Tools for creation of formal metadata
	mp

A compiler for formal metadata

This program is a compiler to parse formal metadata, checking the syntax against the FGDC Content Standard for Digital Geospatial Metadata and generating output suitable for viewing with a web browser or text editor. It runs on UNIX systems and on PC's running Windows 95, 98, or NT. MP generates a textual report indicating errors in the metadata, primarily in the structure but also in the values of some of the scalar elements (i.e. those whose values are restricted by the standard).

The compiler, its source code, executables for UNIX (DG/UX, HP/UX, IRIX, and Linux) and Microsoft Windows 95, 98, and NT, and its own formal metadata are available through

<http://geology.usgs.gov/tools/metadata/>

Usage

Basic usage is

    mp [options] input_file

where input_file is the name of a text file containing metadata encoded as described in the encoding format document or in SGML conforming to a specific Document Type Definition (DTD). These command-line options are available:

	-c cfile    obtains configuration information from cfile
	-e efile    directs syntax errors to efile
	-t tfile    creates text output in tfile
	-h hfile    creates html output in hfile
	-f ffile    creates FAQ-style html output in ffile
	-s sfile    creates sgml output in sfile
	-d dfile    creates DIF  output in dfile

Syntax error messages indicate the nature of discrepancies between the input file and the standard, and the line numbers of the relevant elements in the input file. If -e efile is not specified, syntax errors are written to stderr, which is usually the console (for MS-DOS) or the terminal from which the compiler is launched.

Input

Since the FGDC Content Standard for Digital Geospatial Metadata, as the name implies, specifies only the contents of metadata files and not their encoding, it was necessary to devise a specification for metadata encoding in order to develop and use this compiler. The encoding format is purely textual and the fidelity of the compiler to this format is fanatical.

Note: mp does not read word-processor documents, it only reads ASCII text, SGML, and XML!

Output

Text output, if requested, follows the encoding format. This provides a check of the compiler; any such program should be able to reproduce its input without significant loss of information.
HTML output, if requested, uses descriptive lists to arrange the elements hierarchically. The HEAD element of the metadata contains META elements corresponding to the Dublin Core.
FAQ-style HTML output, if requested, uses the general arrangement of information found in Metadata in Plain Language and re-expresses the metadata in a manner that is easier to read. This format is not parseable in subsequent software processing. To see how mp writes standard metadata elements in this output format, consult
- a specially built input file,
- the config file used to process it with mp, and
- the FAQ-style output that mp generated for it.
Dublin core elements are added to the HEAD element as META tags.
NOTE: mp now provides in its HTML output a link to each of the other output formats that you requested when running mp. These links are relative to the current directory by default, and will work correctly when someone retrieves a metadata record directly through a web server. However, HTML metadata records retrieved through the Clearinghouse gateway interface come tagged with the URL of the gateway, consequently these links will not work by default with HTML records found through the gateway interface. To make these links work without regard to the retrieval method, place a BASE tag into the HEAD element of the output HTML code. As you might guess, mp can do this for you, but it needs to know the URL where your metadata will be available as web pages. It gets this information from a config file entry as follows:
```
output:
  html:
    base: URL
```
So if your web site has a URL like
```
  http://www.our-data.org/metadata/
```
that will contain your metadata records, put this into your config file: output: html: base: http://www.our-data.org/metadata/
```
Obviously you have to use the -c config_file command line option
for mp, substituting for config_file the name of the actual config
file you'll be using.
```
SGML output uses the eight-character tags proposed by the FGDC Clearinghouse Working Group. The SGML output is designed to work with a Document Type Definition (DTD) that I have developed and tested.
XML output uses the eight-character tags given in the 1998 version of the CSDGM. The XML output is designed to work with a Document Type Definition (DTD) that I have developed and tested.
Directory Interchange Format (DIF) output will require editing to fix inconsistencies between the DIF and FGDC metadata standards, and to add information required by DIF that is not clearly identified in the FGDC scheme, such as Entry_ID.

Acknowledgements

Questions, comments, and suggestions are welcome. A number of people have assisted me with performance and portability issues, including Chuck Denham (USGS), Mark Graves (US Army), Sol Katz (BLM), Tom McCulloch (USGS), Eric Miller (OCLC), Doug Nebert (USGS), Tom Northcutt (NASA), Barbara Poore (USGS), Chuck Stein (Mirror Imaging), and Susan Stitt (NBS).

Technical contact:

    Peter N. Schweitzer
    Mail Stop 918, National Center
    U.S. Geological Survey
    Reston, VA 20192

    Tel: (703) 648-6533
    FAX: (703) 648-6560
    Email: pschweitzer@usgs.gov

This file is <http://geology.usgs.gov/tools/metadata/tools/doc/mp.html>
Last updated 29-Apr-1999