随机块读

[c]代码库

#include <process.h> 
#include <string.h> 
#include <stdio.h> 
#include <dos.h> 

int main(void) 
{ 
   char far *save_dta; 
   char line[80], buffer[256]; 
   struct fcb blk; 
   int i, result; 

   /* get user input file name for dta */ 
   printf("Enter drive and file name (no path - i.e. a:file.dat)\n"); 
   gets(line); 

   /* put file name in fcb */ 
   if (!parsfnm(line, &blk, 1)) 
   { 
      printf("Error in call to parsfnm\n"); 
      exit(1); 
   } 
   printf("Drive #%d  File: %s\n\n", blk.fcb_drive, blk.fcb_name); 

   /* open file with DOS FCB open file */ 
   bdosptr(0x0F, &blk, 0); 

   /* save old dta, and set new one */ 
   save_dta = getdta(); 
   setdta(buffer); 

   /* set up info for the new dta */ 
   blk.fcb_recsize = 128; 
   blk.fcb_random = 0L; 
   result = randbrd(&blk, 1); 

   /* check results from randbrd */ 
   if (!result) 
      printf("Read OK\n\n"); 
   else 
   { 
      perror("Error during read"); 
      exit(1); 
   } 

   /* read in data from the new dta */ 
   printf("The first 128 characters are:\n"); 
   for (i=0; i<128; i++) 
      putchar(buffer[i]); 

   /* restore previous dta */ 
   setdta(save_dta); 

   return 0; 
}