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Код: Выделить всё

#include <stdio.h>
     
 int main()
    {
      FILE *file;
     
      char buffer1[5];
      char buffer2[3];
      char buffer3[3];
      char buffer4[5];
      int n,m,k,l;
      int i = 0;

      if (file = fopen("example.txt", "rb"))
    
      {

//     while(!feof(file))
//      {

        n = fread(buffer1, 1, 4, file);    //  возвращает количество считанных байтов
        buffer1[n] = 0;
/* a char array is only a string if it has the null character at the end */


	fseek ( file, n , SEEK_SET );

	m = fread(buffer2, 1, 2, file);
        buffer2[m] = 0;

	fseek ( file, n+m, SEEK_SET);

        k = fread(buffer3, 1, 2, file);
        buffer3[k] = 0;
        
        fseek ( file, n+m+k, SEEK_SET);

        l = fread(buffer4, 1, 4, file);
	buffer4[l] = 0;

      fseek ( file, n+m+k+(long int)buffer4, SEEK_SET);

//     i++;	
        
//	}

        fclose(file);
	printf ("Number of reading %d\n", i-1);
        printf("1st %d characters of the file:\n%s\n", n, buffer1);
        printf("2nd %d characters of the file:\n%s\n", m, buffer2);
        printf("3rd %d characters of the file:\n%s\n", k, buffer3);
	printf("4   %d characters of the file:\n%s\n", l, buffer4);

      }
     
      return 0;
    }

Код: Выделить всё

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>

typedef struct
{
  uint32_t time;
  uint16_t type;
  uint16_t subtype;
  uint32_t length;
} MRT_Struct __attribute__ ((packed));

int main(int argc, char *argv[])
{
  //unsigned long int num_records = 0;
  unsigned long long int num_records = 0;
  MRT_Struct mrt;
  char buf[4096];
  memset(&mrt, 0, sizeof(mrt));
  char *szFile = "rv4-rib";
  if (argc > 1)
  {
    szFile = argv[1];
  }

  FILE *infile;
  if (NULL == (infile = fopen(szFile, "rb")))
    {
      perror ("fopen");
      exit (EXIT_FAILURE);
    }
    else
    {

     while (!feof (infile))
    {
    fread (&mrt, sizeof (mrt), 1, infile);
    mrt.length = ntohl (mrt.length);

    if (feof (infile))
    {
    break;
    }
    fread (buf, mrt.length, 1, infile);
    num_records++;
    }

    }
  printf ("Number of records in file = %d\n", num_records);
  return 0;
}

Код: Выделить всё

fread (buf, mrt.length, 1, infile);

Код: Выделить всё

 char buf[4096]; 

Код: Выделить всё

 int buf[4096];

Код: Выделить всё

mrt.length = ntohl (mrt.length);

Код: Выделить всё

     int
     fseek(FILE *stream, long offset, int whence);

DESCRIPTION
     The fseek() function sets the file position indicator for the stream
     pointed to by stream.  The new position, measured in bytes, is obtained
     by adding offset bytes to the position specified by whence.  If whence is
     set to SEEK_SET, SEEK_CUR, or SEEK_END, the offset is relative to the
     start of the file, the current position indicator, or end-of-file,
     respectively.  A successful call to the fseek() function clears the end-
     of-file indicator for the stream and undoes any effects of the ungetc(3)
     and ungetwc(3) functions on the same stream.

Код: Выделить всё

The mode string can also include the letter ``b'' either as a third char-
     acter or as a character between the characters in any of the two-charac-
     ter strings described above.  This is strictly for compatibility with
     ISO/IEC 9899:1990 (``ISO C90'') and has no effect; the ``b'' is ignored.