fsetpos(S)

fsetpos -- sets the file position indicator for a stream

Syntax

cc . . . -lc

#include  <stdio.h>

int fsetpos(stream, pos)
FILE *stream;
const fpos_t *pos;

Description

The fsetpos function sets the file position indicator for stream to the value of pos, which is obtained in a prior call to fgetpos against stream.

The function clears the end-of-file indicator and undoes any effects of the ungetc(stream). After calling fsetpos, the next operation on stream may be either input or output.

Return value

If successful, the fsetpos function returns 0. On failure, the function returns a nonzero value and sets errno to one of the following manifest constants (defined in stdio.h):

EBADF: The specified stream is not a valid file handle, or is not accessible.
EINVAL: The stream value is invalid.

Standards conformance

fsetpos is conformant with:

ANSI X3.159-1989 Programming Language -- C .

Example

   #include <stdio.h>
   
   FILE *stream;
   fpos_t pos[];
   int val;
   char list[100];
   

   main()
   {
                   /* open file1 */
          if ((stream = fopen ("file1","rb")) == NULL)
                   printf ("Trouble opening file\n");
          else {
                   /* Read some data */
                   fread (list, sizeof(char), 100, stream);
                   /* Save current position */
                   if (fgetpos (stream, &pos) != 0)
                           perror("fgetpos error");
                   /* Read some more */
                   fread (list, sizeof(char), 100, stream);
                   /* Return to saved position */
                   if (fsetpos (stream, &pos) != 0)
                           perror ("fsetpos error");
          }
   }