fig11_11.c

C程序设计经典教程第5版程序示例,比较适合初级c语言的学生

/* Fig. 11.11: fig11_11.c
   Creating a random-access file sequentially */
#include <stdio.h>

/* clientData structure definition */
struct clientData { 
   int acctNum;          /* account number */
   char lastName[ 15 ];  /* account last name */
   char firstName[ 10 ]; /* account first name */
   double balance;       /* account balance */
}; /* end structure clientData */

int main( void )
{ 
   int i; /* counter used to count from 1-100 */

   /* create clientData with default information */
   struct clientData blankClient = { 0, "", "", 0.0 }; 
   
   FILE *cfPtr; /* credit.dat file pointer */

   /* fopen opens the file; exits if file cannot be opened */
   if ( ( cfPtr = fopen( "credit.dat", "wb" ) ) == NULL ) {
      printf( "File could not be opened.\n" );
   } /* end if */
   else { 
 
      /* output 100 blank records to file */
      for ( i = 1; i <= 100; i++ ) {
         fwrite( &blankClient, sizeof( struct clientData ), 1, cfPtr );
      } /* end for */

      fclose ( cfPtr ); /* fclose closes the file */
   } /* end else */

   return 0; /* indicates successful termination */

} /* end main */


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