/***************************************************************************
*
* write_hdr
*
*   Writes the specified values into a 5000-byte header block of the 
*   specified file, using the new standard CDC distributed data header format. 
*
* LAST UPDATE: 26 November 1997
*
* ARGUMENTS:
*
*   Name         Type       Description
*   ----         ----       -----------
*   outfile    *FILE                 Opened output data file pointer
*   hdr        *struct std_hdr       Pointer to std_hdr structure
*
* ORIGINAL AUTHORS:
*   Don Anderson and Wesley Berg, CIRES/CDC, November 1997
*
* RETURNS:   0   If successful
*          < 0   If error
*
* NOTES:
*   (1) The passed file descriptor ("outfile") must be for a file which
*       has already been opened for writing.
*   (2) Binary write (fwrite) continues up to the 5000th byte of the file
*       (end of header)
*
***************************************************************************/

#include <stdio.h>
#include "common_structures"

 int write_hdr ( FILE *outfile, struct std_hdr hdr )

 {

 char   buff[5000] ;      /* Buffer for filler bytes  */
 int    error_flag ;      /* Error flag               */
 short  i ;               /* Generic counter          */

 error_flag = 0 ;

 fwrite ( hdr.filename, 1, 80, outfile ) ;
 fwrite ( hdr.satellite, 1, 20, outfile ) ;
 fwrite ( hdr.sensor, 1, 20, outfile ) ;
 fwrite ( &hdr.satid, 2, 1, outfile ) ;
 fwrite ( &hdr.fields, 2, 1, outfile ) ;
 fwrite ( &hdr.pixperscan, 2, 1, outfile ) ;
 fwrite ( &hdr.hifields, 2, 1, outfile ) ;
 fwrite ( &hdr.hipixperscan, 2, 1, outfile ) ;
 fwrite ( &hdr.missing_val, 2, 1, outfile ) ;
 for ( i = 0 ; i < hdr.fields + hdr.hifields ; i++ ) 
   {
   fwrite ( &hdr.scale[i], 4, 1, outfile ) ;
   fwrite ( &hdr.offset[i], 4, 1, outfile ) ;
   fwrite ( &hdr.units[i], 1, 40, outfile ) ;
   fwrite ( &hdr.description[i], 1, 80, outfile ) ;
   }

 if (!fwrite (buff,1,5000-132-((hdr.fields+hdr.hifields)*128),outfile))
   error_flag = -1 ;

 return ( error_flag ) ;
 }