fsetpos

 NAME
  fsetpos - set position within file pointer (nearly equivalent to
  fseek absolute)

 SYNOPSIS
  #include <stdio.h>

  int error = fsetpos(fp, &pos);
  FILE *fp;
  fpos_t pos;

 FUNCTION
  fsetpos() is a nearly useless call that is essentially the same
  as fseek(fp, (long)pos, 0);  fsetpos() seeks within a file pointer
  to the absolute position specified by an fpos_t type.  The
  address of an fpos_t object is passed to fsetpos().

  Normally one saves the current seek position into an fpos_t
  type using the fgetpos() function, then seeks back using
  the fsetpos() function.  In this way the programmer need not make
  any direct reference to the contents of the fpos_t type.

 EXAMPLE
  /*
   *  get a line, save current position, get rest of file, go back
   *  to saved position, retrieve line again and print again.
   */

  #include <stdio.h>

  main(ac, av)
  int ac;
  char **av;
  {
      FILE *fp;
      fpos_t save_pos;
      int count;
      char buf[256];

      if (ac == 1) {
      puts("Expected textfile argument");
      exit(1);
      }
      fp = fopen(av[1], "r");
      if (fp == NULL) {
      printf("Unable to open %sn", av[1]);
      exit(1);
      }
      for (count = 0; fgets(buf, sizeof(buf), fp); ++count) {
      if (count == 0)             /*  just before second line */
          fgetpos(fp, &save_pos);
      fprintf(stdout, "%-3d: %s", count + 1, buf);
      }
      if (count < 2) {
      puts("not enough lines in file for example!");
      exit(1);
      }
      puts("--end of file, now seeking back to line 2--");
      fsetpos(fp, &save_pos);
      if (fgets(buf, sizeof(buf), fp) == NULL) {
      puts("error!");
      exit(1);
      }
      fprintf(stdout, "%-3d: %s", 2, buf);
      fclose(fp);
      return(0);
  }

 INPUTS
  FILE *fp;       file pointer to seek
  fpos_t *pos;    pointer to fpos_t type previously initialized
                  by a fgetpos() call.

 RESULTS
  int error;      0 if no error, < 0 if error

 SEE ALSO
  ftell, fsetpos, fseek, rewind