seekgb.c File Reference

Searches a file for the next GRIB message. More...

#include <stdio.h>
#include <stdlib.h>
#include "grib2_int.h"

Go to the source code of this file.

Macros
#define	BITS_PER_BYTE   8
	8 bits per byte. More...

Functions
void	seekgb (FILE *lugb, g2int iseek, g2int mseek, g2int *lskip, g2int *lgrib)
	This subprogram searches a file for the next GRIB Message. More...

Detailed Description

Searches a file for the next GRIB message.

Author

Stephen Gilbert

Date

2002-10-28

Definition in file seekgb.c.

Macro Definition Documentation

BITS_PER_BYTE

#define BITS_PER_BYTE   8

8 bits per byte.

Definition at line 10 of file seekgb.c.

Function Documentation

seekgb()

void seekgb	(	FILE *	lugb,
		g2int	iseek,
		g2int	mseek,
		g2int *	lskip,
		g2int *	lgrib
	)

This subprogram searches a file for the next GRIB Message.

The search is done starting at byte offset iseek of the file referenced by lugb for mseek bytes at a time. If found, the starting position and length of the message are returned in lskip and lgrib, respectively. The search is terminated when an EOF or I/O error is encountered.

Program History Log

Date	Programmer	Comments
2002-10-28	GILBERT	Modified from Iredell's skgb subroutine
2009-01-16	VUONG	Changed lskip to 4 instead of sizof(g2int)

Parameters

lugb	FILE pointer for the file to search. File must be opened before this routine is called.
iseek	number of bytes in the file to skip before search.
mseek	number of bytes to search at a time (must be at least 16).
lskip	number of bytes to skip from the beggining of the file to where the GRIB message starts.
lgrib	number of bytes in message (set to 0, if no message found).

Author

Stephen Gilbert

Date

2002-10-28

Definition at line 39 of file seekgb.c.

References BITS_PER_BYTE, and gbit().