Read a GRIB2 index file and return its contents. More...

Functions/Subroutines
subroutine	getg2i (LUGI, CBUF, NLEN, NNUM, IRET)
	Read a GRIB2 index file and return its contents. More...

Detailed Description

Read a GRIB2 index file and return its contents.

Definition in file getg2i.F90.

Function/Subroutine Documentation

subroutine getg2i	(	integer, intent(in)	LUGI,
		character(len=1), dimension(:), pointer	CBUF,
		integer, intent(out)	NLEN,
		integer, intent(out)	NNUM,
		integer, intent(out)	IRET
	)

Read a GRIB2 index file and return its contents.

The index file may be generated by the grb2index utility of the NCEPLIBS-grib_util project.

The index file has two header records:

an 81-byte header with 'GB2IX1' in columns 42-47
an 81-byte header with number of bytes to skip before index records, total length in bytes of the index records, number of index records, and GRIB file basename written in format ('IX1FORM:',3i10,2x,a40).

Each record in the index table contains the following fields. All integers are in big-endian format in the file.

byte 001 - 004 length of index record
byte 005 - 008 bytes to skip in data file before grib message
byte 009 - 012 bytes to skip in message before lus (local use) set = 0, if no local section.
byte 013 - 016 bytes to skip in message before gds
byte 017 - 020 bytes to skip in message before pds
byte 021 - 024 bytes to skip in message before drs
byte 025 - 028 bytes to skip in message before bms
byte 029 - 032 bytes to skip in message before data section
byte 033 - 040 bytes total in the message
byte 041 - 041 grib version number (currently 2)
byte 042 - 042 message discipline
byte 043 - 044 field number within grib2 message
byte 045 - ii identification section (ids)
byte ii+1- jj grid definition section (gds)
byte jj+1- kk product definition section (pds)
byte kk+1- ll the data representation section (drs)
byte ll+1-ll+6 first 6 bytes of the bit map section (bms)

Note: Subprogram can be called from a multiprocessing environment. Do not engage the same logical unit from more than one processor.

Parameters

[in]	lugi	Integer unit of the unblocked GRIB index file. Must be opened by baopen() or baopenr().
[out]	cbuf	Pointer to a buffer that will get the index records. Memory will be allocated within this function, so callers must free the memory that cbuf points to, using deallocate(cbuf) when cbuf is no longer needed.
[out]	nlen	Total length of all index records.
[out]	nnum	Number of index records.
[out]	iret	Return code. 0 No error. 2 not enough memory to hold index buffer 3 error reading index file buffer 4 error reading index file header

Definition at line 58 of file getg2i.F90.

Referenced by getgb2p(), and getidx().