/*****************************************************************

                  SUBROUTINE FINDCRUISE

 FINDCRUISE PLACES ALL THE RECORD NUMBERS FOR A USER INPUT
 CRUISE INTO AN ARRAY FOR USE IN THE MAIN PROGRAM.

******************************************************************/

/*****************************************************************

 MAKE INC A WRITE2 STRUCTURE (TWO INTEGERS).  THE FIRST INTEGER
 IS THE NUMBER OF PROFILES IN A CRUISE, THE SECOND IS THE LOCATION
 OF THE RECORD NUMBER FOR THE FIRST PROFILE IN A CRUISE, IN
 THE PRIMARY FILE.

******************************************************************/

struct write2 inc;

findcruise_(

 int *choice,       /* USER INPUT CRUISE NUMBER */

 int *nproc,        /* NUMBER OF PROFILES FOR THIS CRUISE */

 int *icgrid,       /* RECORD NUMBERS OF PROFILES FOR THIS CRUISE */

 int *fn,           /* FILE IDENTIFICATION NUMBER FOR FILE
                       CONTAINING CRUISE NUMBER AND POSITION OF
                       INFORMATION ON CRUISE IN SECONDARY FILE */

 int *fn1,          /* FILE IDENTIFICATION NUMBER FOR FILE CONTAINING 
                       RECORD NUMBERS SORTED BY CRUISE 
                       (PRIMARY FILE) */ 

 int *fn2           /* FILE IDENTIFICATION NUMBER FOR FILE CONTAINING
                       NUMBER OF PROFILES FOR A CRUISE AND LOCATION
                       IN PRIMARY FILE OF RECORD NUMBER OF FIRST
                       PROFILE (SECONDARY FILE) */

            )

{

/****************************************************************

 INTERNAL VARIABLES:

  CNUM - CRUISE NUMBER READ IN FROM INDEX FILE
  INDEX - ORDER OF CRUISE IN INDEX FILE (ALSO POSITION OF
          CRUISE INFORMATION IN SECONDARY FILE)

******************************************************************/

 int cnum = 0;
 int index = 0;

/*****************************************************************

 READ THROUGH INDEX FILE UNTIL REQUESTED CRUISE NUMBER IS FOUND
 ADD ONE TO INDEX FOR EACH CRUISE NUMBER READ IN.

******************************************************************/

 fseek( fp[*fn], 0L, SEEK_SET );
 while ( cnum != *choice && !feof( fp[*fn] ) ) {

  fread( &cnum, sizeof( int ), 1, fp[*fn] );
  index +=1;

 }

/****************************************************************

 IF THE CRUISE NUMBER WAS NOT FOUND, SET NUMBER OF PROFILES TO
 -1 AND RETURN TO MAIN PROGRAM.

*****************************************************************/

 if ( feof( fp[*fn] ) ) {

  *nproc = -1;
  fseek( fp[*fn], 0L, SEEK_SET );
  return;

 }

/****************************************************************

 USE INDEX TO GO TO THE CORRECT POSITION IN THE SECONDARY FILE
 TO READ IN INFORMATION ON THE CRUISE

 READ IN THE NUMBER OF PROFILES IN THIS CRUISE (INC.NUM) AND
 THE STARTING POSITION OF PROFILE RECORD NUMBERS (INC.REC).

*****************************************************************/

 fseek( fp[*fn2], (index-1) * sizeof( struct write2 ), SEEK_SET );
 fread( &inc, sizeof( struct write2 ), 1, fp[*fn2] );

/****************************************************************

 USE THIS INFORMATION TO SCROLL TO THE PROPER POSITION IN THE
 PRIMARY FILE AND TO SET THE NUMBER OF PROFILES.

*****************************************************************/

 fseek( fp[*fn1], inc.rec * sizeof( int ), SEEK_SET );
 *nproc = inc.num;

/****************************************************************

 READ IN THE PROFILE NUMBERS TO ARRAY ICGRID

*****************************************************************/

 fread( icgrid, sizeof( int ), *nproc, fp[*fn1] );

/***************************************************************

 REWIND FILES

****************************************************************/

 fseek( fp[*fn], 0L, SEEK_SET );
 fseek( fp[*fn1], 0L, SEEK_SET );
 fseek( fp[*fn2], 0L, SEEK_SET );
}