Fortran 200x interface to the libudunits2 library from Unidata
(currently modeled after version 2.0.4, but should work with subsequent versions)
the C library libudunits2 is
Copyright University Corporation for Atmospheric Research and contributors
this Fortran Interface is
Copyright Université du Québec à Montréal (UQAM) 2012-2021
a version of the Fortran compiler that supports
use ISO_C_BINDING
is needed (development/testing done originally with gfortran 4.6)
recent versions of the GNU / Portland group / Intel / IBM xlf compilers should work
recently tested with GNU Fortran, Nvidia, AOCC, Intel Fortran compilers
GNU Fortran (GCC) 11.1.0
AMD clang version 13.0.0 (CLANG: AOCC_3.2.0-Build#128 2021_11_12) (based on LLVM Mirror.Version.13.0.0)
ifort (IFORT) 2021.4.0 20210910
pgfortran (aka nvfortran) 21.11-0 64-bit target on x86-64 Linux
for all the C functions that have been interfaced:
0- the calling Fortran code must include
use f_udunits_2
to use these Fortran functions/subroutines
1- the Fortran name will be the C name prefixed with f_
Fortran function f_ut_read_xml mimics C function ut_read_xml
2- where the C code uses a typed pointer, the Fortran code uses a typed object
type(UT_SYSTEM_PTR) replaces ut_system*
type(UT_UNIT_PTR) replaces ut_unit*
type(CV_CONVERTER_PTR) replaces cv_converter*
3- where a C function has a void return, a Fortran subroutine is used
4- where a C function returns zero/nonzero for a C style true/false
the equivalent Fortran function returns a Fortran logical
(to be usable in an equivalent way in a logical expression)
5a- where a C input argument is char *, the Fortran code uses character(len=*)
copy to a C compatible zero terminated string is handled internally
the Fortran string is "trailing blanks trimmed" before the zero byte is added
5b- where a C function returns char *, the Fortran function return type is character(len=256)
6- ut_status is an integer, symbols with the same name are available to Fortran with
use f_udunits_2
7- ut_encoding is an integer, symbols with the same name are available to Fortran with
use f_udunits_2
NOTES:
Fortran interface(s) for function(s) returning char * (ut_trim) not implemented
one should use the Fortran trim function (may not work in all cases)
Fortran interfaces to "visitor" functions are not implemented
ut_accept_visitor (const ut_unit* unit, const ut_visitor* visitor, void* arg)
Data type: ut_visitor
Fortran interfaces to functions using a variable argument list and message handler
are not implemented
int ut_handle_error_message (const char* fmt, ...)
ut_error_message_handler ut_set_error_message_handler (ut_error_message_handler handler)
int ut_write_to_stderr (const char* fmt, va_list args)
int ut_ignore (const char* fmt, va_list args)
int ut_ignore (const char* fmt, va_list args)
typedef int (*ut_error_message_handler)(const char* fmt, va_list args);
see C API documentation https://www.unidata.ucar.edu/software/udunits/udunits-2.0.4/udunits2lib.html