static char rcsid[]="$Id: testif.c,v 1.0 1992/07/28 23:07:53 maurer $";       
/***********************************************************************      
                                                                              
  testif.c                                                                    
                                                                              
  Function:  program illustrates how to read SIF/OIF image data files         
                                                                              
  This file is part of the STARLab Magellan Altimeter Data Processing         
  Software.  Joe Twicken, June 1992.                                          
                                                                              
***********************************************************************/      
/* $Log: testif.c,v $                                                         
 * Revision 1.0  1992/07/28  23:07:53  maurer                                 
 * Initial revision                                                           
 * */                                                                         
                                                                              
#include <stdio.h>                                                            
                                                                              
#include "scvdr.h"                                                            
#include "scvparse.h"                                                         
                                                                              
#include "scvparse.i"                                                         
#include "scv_rdr.i"                                                          
                                                                              
#define RECNUM 10               /* Number data recs to read at once */        
                                                                              
int                                                                           
main(argc,argv)                                                               
int argc;                       /* Number of program arguments */             
char *argv[];                   /* Argument strings */                        
{                                                                             
        sfdu sf1;               /* CCSDS header SFDU label */                 
        sfdu sf2;               /* Keyword/value SFDU label */                
        sfdu sf3;               /* Image header SFDU label */                 
        sfdu sf4;               /* Aggr start marker SFDU label */            
                                                                              
        keyval_t *kv2;          /* Catalog keyword/value list */              
        keyval_t *kv4;          /* Aggr smarker keyword/value list */         
                                                                              
        ih_rec ih;              /* Image header record */                     
        ir_rec ir[RECNUM];      /* Image data records */                      
                                                                              
        int orb,ver;            /* Orbit and version */                       
        int nrec;               /* Number of data records remaining */        
        int nread;              /* Number of data records to read */          
        int nfoot;              /* Footprint number */                        
                                                                              
        float inten;            /* Cumulative intensity */                    
                                                                              
        char product_file_name[80];/* Product file name */                    
                                                                              
        FILE *f_if;             /* SIF/OIF file pointer */                    
                                                                              
        /* Check usage */                                                     
                                                                              
        if (argc != 2) {                                                      
                fprintf(stderr,"usage: testif sif/oif_file\n");               
                exit(1);                                                      
        }                                                                     
                                                                              
        /* Open the SIF/OIF file for reading */                               
                                                                              
        if ((f_if = fopen(argv[1],"r")) == NULL) {                            
                fprintf(stderr,                                               
                        "testif: [main] can't open %s\n",argv[1]);            
                exit(2);                                                      
        }                                                                     
                                                                              
        /* Read the 4 header SFDU's. Remember to free the keyword/value       
           list pointers with free_catalog() when they are no longer          
           needed */                                                          
                                                                              
        if (hdr_read(f_if,&sf1,&sf2,&kv2,&sf3,&ih,&sf4,&kv4)) {               
                fprintf(stderr,                                               
                        "testif: [main] can't read sif/oif header\n");        
                exit(3);                                                      
        }                                                                     
                                                                              
        /* Do something with the header values. The example here shows        
           how to get the orbit, version, record number and product file      
           name */                                                            
                                                                              
        orb  = ih.ih_orb;                                                     
        ver  = ih.ih_ver;                                                     
        nrec = ih.ih_nrec;                                                    
        strncpy(product_file_name,kv2[0].val,sizeof(product_file_name));      
                                                                              
        /* Allocate space for the variable length fields in the image         
           data records. sif_oif_allocn() need only be called once per        
           orbit; sufficient memory space is allocated to accommodate         
           the largest possible data record */                                
                                                                              
        if (sif_oif_allocn(ir,RECNUM,&ih)) {                                  
                fprintf(stderr,                                               
                        "testif: [main] can't allocate memory space\n");      
                exit(4);                                                      
        }                                                                     
                                                                              
        /* Read image data records, 10 at a time */                           
                                                                              
        while (nrec > 0) {                                                    
                                                                              
                /* Read the data records 10 at a time. Note that              
                   sif_oif_readn() returns the number of records              
                   successfully read */                                       
                                                                              
                nread = (nrec > RECNUM) ? RECNUM : nrec;                      
                if (sif_oif_readn(f_if,ir,nread) != nread) {                  
                        fprintf(stderr,                                       
                       "testif: [main] can't read sif/oif data recs\n");      
                        exit(5);                                              
                }                                                             
                nrec -= nread;                                                
                                                                              
                /* Do somethings with the data values. The example here       
                   shows how to read the footprint number and the             
                   intensity value from the first angle in the first          
                   data record */                                             
                                                                              
                nfoot = ir[0].ir_nfoot;                                       
                inten = ir[0].ir_bins[0].inten;                               
        }                                                                     
                                                                              
        /* Free the memory allocated for the variable length fields           
           in the image data records. The sif_oif_freen() routine must        
           be called once for each call to sif_oif_allocn() */                
                                                                              
        sif_oif_freen(ir,RECNUM);                                             
                                                                              
        /* Free the header keyword/value lists */                             
                                                                              
        free_catalog(kv2);                                                    
        free_catalog(kv4);                                                    
                                                                              
        /* Close the SIF/OIF file */                                          
                                                                              
        fclose(f_if);                                                         
                                                                              
        return(0);                                                            
}