$Id: README,v 1.8 1997/05/22 14:53:36 steve Exp $


INTRODUCTION:

This package contains sources for the Unidata units library (udunits(3))
the conversion utility (udunits(1)) and an optional perl extension
module (UDUNITS).



PACKAGE COMPONENTS:

    Directory		Contents
    ---------		--------

    lib			Source for the units library, libudunits.a.

    udunits		Source for the units program, udunits.

    perl		Source for the perl 5 extension for UDUNITS.
			This only works for version 5 of perl.

    port		Portability stuff and miscellaneous support
			functions.



INSTALLATION:

Please read the file INSTALL and follow its instructions.

If you have a problem installing the package, then please include the
following in any request for assistance from the Unidata Program Center:

    1.  The standard output of the command "uname -a".

    2.  The standard and error output of the configure script.

    3.  The file "config.log".

    4.  The standard and error output of the "make" command.

SunOS 4 Note:
    If you use Sun's unbundled C compiler (acc), then you might have to 
    change the `char *' argument declarations in memory.h to `void *' 
    in order to compile utparse.y.  This is a problem with Sun's header 
    files: the declarations in memory.h conflict with those in string.h.

Time-handling Note:
    There is a problem in the handling of time in all versions of the
    UDUNITS library prior to version 1.10.  The temporal algorithms in
    the pre-1.10 libraries are valid only for times after October 15,
    1582 (when the Gregorian calendar was adopted).  At some time prior
    to that point, the algorithms return incorrect results.  This has
    caused problems for at least one user who used a temporal unit of
    "hours since 1-1-1".  The exact time at which the algorithms break
    down is unknown, but year 1 is definitely in the invalid region.



USE:

To use the UDUNITS package, reference it in your compile and link 
commands, e.g.

    cc -c -I/usr/local/include ...
    cc ... -L/usr/local/lib -ludunits ...

Here are some notes for specific operating systems:

    AIX:

	Use the "-qextname" when compiling FORTRAN sources that use the
	UDUNITS package.  This option separates the FORTRAN and C
	namespaces -- obviating many problems.  The UDUNITS library
	should have been built using this option.

    HP-UX:

	Use the "+ppu" when compiling FORTRAN sources that use the
	UDUNITS package.  This option separates the FORTRAN and C
	namespaces -- obviating many problems.  The UDUNITS library
	should have been built using this option.



FEEDBACK:

Please send questions, bug reports, complaints, praise, criticisms, etc. to
the following address at the Unidata Program Center:

	support@unidata.ucar.edu
