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g2_addlocal.c
Go to the documentation of this file.
#include "grib2_int.h"
#include <stdio.h>
g2int
g2_addlocal(unsigned char *cgrib, unsigned char *csec2, g2int lcsec2)
{
static g2int two = 2;
g2int j, k, lensec2, iofst, ibeg, lencurr, ilen, len, istart;
g2int isecnum;
int ret;
/* Check for GRIB header and terminator. Translate the error codes
* to the legacy G2 error codes. */
if ((ret = g2c_check_msg(cgrib, &lencurr, 1)))
{
if (ret == G2C_ENOTGRIB)
return G2_ADD_MSG_INIT;
if (ret == G2C_EMSGCOMPLETE)
return G2_ADD_MSG_COMPLETE;
}
/* Loop through all current sections of the GRIB message to find
* the last section number. */
len = 16; /* length of Section 0 */
for (;;)
{
/* Get section number and length of next section. */
iofst = len * 8;
gbit(cgrib, &ilen, iofst, 32);
iofst = iofst + 32;
gbit(cgrib, &isecnum, iofst, 8);
len = len + ilen;
/* Exit loop if last section reached. */
if (len == lencurr)
break;
/* If byte count for each section doesn't match current total
* length, then there is a problem. */
if (len > lencurr)
{
printf("g2_addlocal: Section byte counts don't add to total.\n");
printf("g2_addlocal: Sum of section byte counts = %ld\n", len);
printf("g2_addlocal: Total byte count in Section 0 = %ld\n", lencurr);
return G2_BAD_SEC_COUNTS;
}
}
/* Section 2 can only be added after sections 1 and 7. */
if (isecnum != 1 && isecnum != 7)
{
printf("g2_addlocal: Section 2 can only be added after Section 1 or Section 7.\n");
printf("g2_addlocal: Section %ld was the last found in given GRIB message.\n", isecnum);
return G2_BAD_SEC;
}
/* Add Section 2 - Local Use Section. */
ibeg = lencurr * 8; /* Calculate offset for beginning of section 2 */
iofst = ibeg + 32; /* leave space for length of section */
sbit(cgrib, &two, iofst, 8); /* Store section number (2) */
istart = lencurr + 5;
k = 0;
for (j = istart; j < istart + lcsec2; j++)
cgrib[j] = csec2[k++];
/* Calculate length of section 2 and store it in octets 1-4 of
* section 2. */
lensec2 = lcsec2 + 5; /* bytes */
sbit(cgrib, &lensec2, ibeg, 32);
/* Update current byte total of message in Section 0. */
lencurr += lensec2;
sbit(cgrib, &lencurr, 96, 32);
return lencurr;
}
g2_addlocal
g2int g2_addlocal(unsigned char *cgrib, unsigned char *csec2, g2int lcsec2)
Adds a Local Use Section (Section 2) to a GRIB2 message.
Definition g2_addlocal.c:41
gbit
void gbit(unsigned char *in, g2int *iout, g2int iskip, g2int nbits)
Get arbitrary size values from a packed bit string, right justifying each value in the unpacked iout ...
Definition gbits.c:20
sbit
void sbit(unsigned char *out, g2int *in, g2int iskip, g2int nbits)
Store arbitrary size values into a packed bit string, taking the low order bits from each value in th...
Definition gbits.c:38
G2_BAD_SEC_COUNTS
#define G2_BAD_SEC_COUNTS
Sum of Section byte counts doesn't add to total byte count.
Definition grib2.h:468
G2_BAD_SEC
#define G2_BAD_SEC
Previous Section was unexpected.
Definition grib2.h:456
G2_ADD_MSG_COMPLETE
#define G2_ADD_MSG_COMPLETE
GRIB message already complete.
Definition grib2.h:467
G2_ADD_MSG_INIT
#define G2_ADD_MSG_INIT
GRIB message was not initialized - call g2_create() first.
Definition grib2.h:466
G2C_ENOTGRIB
#define G2C_ENOTGRIB
GRIB header not found.
Definition grib2.h:486
G2C_EMSGCOMPLETE
#define G2C_EMSGCOMPLETE
GRIB message already complete.
Definition grib2.h:487
g2int
int64_t g2int
Long integer type.
Definition grib2.h:32
grib2_int.h
Header file with internal function prototypes NCEPLIBS-g2c library.
g2c_check_msg
int g2c_check_msg(unsigned char *cgrib, g2int *lencurr, int verbose)
Check for 'GRIB' at the beginning of a GRIB message, and check to see if the message is already termi...
Definition util.c:26