PortLib
=============================================

The module is available through the NTCC Webpage,
w3.pppl.gov/NTTC  under "Modules Library", as compressed
tarfile, portlib.tar.gz, and as zip archive, portlib.zip.
Alternatively it can be obtained from ftp.pppl.gov
in pub/NTCC/.

For documentation see:
http://w3.pppl.gov/ntcc/Port


o AUTHOR
  D. McCune dmccune@pppl.gov 

o CONTACT
  ntcc_webmaster@pppl.gov  
  D. McCune : dmccune@pppl.gov 
  C. Ludescher-Furth : cludesche@pppl.gov

****************
REVISION HISTORY
****************
      date         Description

  May 15, 1999  -- Created
  May 15, 2000  -- Update of README / Makefile

----------------------------------------------------------------

Index:
   1. CONTENTS
   2. UNPACKING INSTRUCTIONS
   3. DESTINATIONS
   4. BUILDING INSTRUCTIONS
   5. RUNNING INSTRUCTIONS
   6. TESTING INSTRUCTIONS
   7. FINAL INSTALLATION
   8. ABSTRACT

************
1. CONTENTS:
************
   Makefile:     NOTE, "GNU make" must be used
                 (usually in /usr/gnu/bin or /usr/local/bin).
                 Main Makefile to invoke Makefile(s) in subdirectories
                 (allows for several modules to be built with one step).

-- in subdirectory portlib:

   README:   This file.  Brief descriptions of the other files, and
             instructions for compiling libportlib.a  and a test. 

   Makefile: Makefile to build library and test. 

   Sources to build libportlib.a:
             *.F, *.f, *.f9f, *.c, *.h

   Test program:  porttest.F  
     

-- in subdirectory fpreproc:
   Python scripts for fortran pre-processing.

-- in subdirectory share:
   Make.flags:  Include file for Makefile, to setup Flags, etc.


**************************
2. UNPACKING INSTRUCTIONS:
**************************

for tarfiles:
  > gunzip portlib.tar.gz
  > tar xvf portlib.tar

or, for zip archives:
  > unzip portlib.zip


****************
3. DESTINATIONS:
****************
Or where do the files go?

When you extract the tar file you get three sub directories:
./portlib  --  sources and Makefile
./share    --  include file Make.flags 

The location of the following subtrees, containing binaries, can be
controlled via environment variable "OBJ".
   
test        : test program
lib         : the actual library modules
obj/portlib : temporary for objects


By default above directories are created in ./<MACHINE>/, where
MACHINE is defined in Make.flags.
e.g.: if you are running Linux, the destination would be ./LINUX/obj, etc.

You can overwrite the destination by defining OBJ, as an environment
variable (e.g. export OBJ=/dir1/dir2),
or with make (e.g. "make  OBJ=.").
If OBJ is defined, the destinations will be
$OBJ/lib and $OBJ/test.
If OBJ is defined as "." then, in the example above, the destination
would be $HOME/foo/lib.

The rational behind <MACHINE> is to facilitate building for various platforms.

Note: If you define OBJ as option to gmake, you have to consistently do so;
      e.g: gmake clean OBJ=., gmake install OBJ=.

*************************
4. BUILDING INSTRUCTIONS:
************************* 

> gmake            -- to build/link library and porttest

> gmake libs       -- to build library only
> gmake clean      -- to remove all .o files
> gmake realclean  -- to remove everything but sources.



Compiling on Linux:
-------------------

At present, there is no native Linux  fortran 90 compiler. However, many
vendors offer good quality compilers. The following have been successfully
used:

-Fujitsu f95
-PGI pgf77 / pgf90

By default the Makefile will select Fujitsu f95.

To select a different compiler define
FORTRAN_VARIANT to "Portland"  "NagWare"  "Fujitsu" or "Absoft"
e.g.:
setenv FORTRAN_VARIANT Portland (csh)
FORTRAN_VARIANT=Portland; export  FORTRAN_VARIANT (sh)

Alternatively, FORTRAN_VARIANT can be passed directly to the gmake
command, as in:
gmake  FORTRAN_VARIANT=Portland

To use vastf90:
> gmake all VAST90=y

Caveat: Be careful to use the same compiler for all objects.


Compiling on Alpha Linux:
-------------------------
The Makefile assumes the Compaq compiler and specifies the 
 " -assume no2underscores " option.

Therefore the calling user software must also be compiled with this
option to link.


Compiling on SUN:
-----------------
The Makefile specifies the " -fast " option which includes -dalign.
Therefore the calling user software must also be compiled with this
option to link.


***********
5. TESTING:
***********

cd <MACHINE>/test  or  cd $OBJ/test
./porttest

**********************
7. FINAL INSTALLATION:
**********************

Choose or create the root directory in which you wish to install the software.
A common location would be /usr/ntcc, but installation can occur in any
directory where you have appropriate permissions.

You define your choice of root directory via PREFIX.
The default for PREFIX is /usr/ntcc.

The assumptions are:

libraries in: $PREFIX/lib        = $LIBDIR       
man pages in: $PREFIX/man/man3   = $MANDIR/man3

To install the software, return to the top directory (the directory,
where you downloaded the tar files) and type

> gmake install  
    to install into /usr/ntcc/...

> gmake install PREFIX=/dir1/dir2/
    to install into /dir1/dir2/...

If you want things elsewhere, you can overwrite the default with
> gmake install LIBDIR=/yyy MANDIR=/zzz

NOTE:
-----
The library is installed as libportlib.a
Users should link with

-L<PREFIX>/lib -lportlib

Make sure users know what <PREFIX> is.

After you have installed the software, you can delete the entire tree
with
> cd ..
> rm -r foo
   assuming the previous example.



************
8. ABSTRACT
************

There are a number of "operating systems support" functions that are frequently
needed in programs, for which no standard interface is available. Examples of 
such functions are: access to the shell, access to command line arguments, 
access to environment variables, elapsed cpu time, and so
on. In UNIX terminology these are the fortran "3f" routines: system, getarg, 
getenv, etc. Accessing these routines requires slightly different code, 
depending on vendor or operating system.
    The portlib library provides a standardized portable interface to these 
routines, encapsulating the system to system variability, making it easier for 
the applications developer to achieve portability without the need to resort to
such techniques as conditional compilation via cpp directives. 

-------------------------------------------------------------------------------

IF YOU HAVE ANY PROBLEMS, PLEASE CONTACT EITHER:


        Doug McCune, Princeton University
                dmccune@pppl.gov
        or

        Christiane Ludescher-Furth, Princeton University
                cludescher@pppl.gov
        or      
                ntcc_webmaster@pppl.gov
