g2_unpack2.c

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#include <stdio.h>
#include <stdlib.h>
#include "grib2.h"
 
g2int
g2_unpack2(unsigned char *cgrib, g2int *iofst, g2int *lencsec2,
           unsigned char **csec2)
{
    g2int ierr = 0, isecnum;
    g2int lensec, ipos, j;
 
    *lencsec2 = 0;
    *csec2 = NULL;
 
    gbit(cgrib, &lensec, *iofst, 32);        /* Get Length of Section */
    *iofst = *iofst + 32;
    *lencsec2 = lensec - 5;
    gbit(cgrib, &isecnum, *iofst, 8);         /* Get Section Number */
    *iofst = *iofst + 8;
    ipos = (*iofst/8);
 
    if ( isecnum != 2 )
    {
        ierr = 2;
        *lencsec2 = 0;
        fprintf(stderr, "g2_unpack2: Not Section 2 data.\n");
        return(ierr);
    }
 
    if (*lencsec2 == 0)
    {
        ierr = 0;
        return(ierr);
    }
 
    if (!(*csec2 = malloc(*lencsec2 + 1)))
    {
        ierr = 6;
        *lencsec2 = 0;
        return(ierr);
    }
 
    /*printf(" SAGIPO %d \n", (int)ipos);*/
    for (j = 0; j < *lencsec2; j++)
        *(*csec2 + j) = cgrib[ipos + j];
 
    *iofst = *iofst + (*lencsec2 * 8);
 
    return(ierr);    /* End of Section 2 processing */
}