Example

       #include <stdio.h>
       #include <stdlib.h>

       main()
       {
           FILE *fp;
           int stat,
               i;
           int character;
           char ch,
                c_ptr[130],
                d_ptr[130];
           fpos_t posit;

           /* Open a file for writing.  */

           if ((fp = fopen("file.dat", "w+")) == NULL) {
               perror("open");
               exit(1);
           }

          /* Get the beginning position in the file.  */

           if (fgetpos(fp, &posit) != 0)
               perror("fgetpos");

           /* Write some data to the file. */

           if (fprintf(fp, "this is a test\n") == 0) {
               perror("fprintf");
               exit(1);
           }

           /* Set the file position back to the beginning. */

           if (fsetpos(fp, &posit) != 0)
               perror("fsetpos");

           fgets(c_ptr, 130, fp);
           puts(c_ptr);        /* Should be "this is a test."  */

           /* Close the file. */

           if (fclose(fp) != 0) {
               perror("close");
               exit(1);
           }

       }