fseek

#include <stdio.h>

int fseek  (
    FILE* stream,    /* file stream */
    long offset,     /* file position offset */
    int  origin);    /* initial offset origin */

The function fseek positions the file cursor to a new location. The parameter stream is a file pointer defining the file. The parameter offset is a long value defining the number of bytes to move. The parameter origin is an integer defining the file cursor location.

The function is included in the library RL-FlashFS. The prototype is defined in the file stdio.h.

The parameter origin can have one of the following values:

The file cursor can be positioned anywhere within the file. FlashFS does not allow fseek to position file cursor past the end of the file. Attempts to position the file cursor past the end of the file causes an error.

note

When using EFS, fseek works only for files opened in read mode. Seeking within files opened for writing is not supported.

• 0 - on success.
• EOF - on error.

ftell, rewind

#include <rtl.h>
#include <stdio.h>

void tst_fseek (void)  {
  FILE *fin;
  char ch;

  fin = fopen ("Test.txt","r");
  if (fin != NULL)  {
    fseek (fin, 5L, SEEK_SET);                     // Read the 5th character from file
    ch = fgetc (fin);
    fseek (fin, -1L, SEEK_END);                    // Read the last character from file
    ch = fgetc (fin);
    fclose (fin);
  }
}