fgetpos example in C

Header file:

    stdio.h

Synopsis:

     int fgetpos(FILE *stream, fpos_t *ptr);

Description:

     fgetpos gets the current position of file pointer(stream) in *ptr.  Returns 0 on  success, non-zero on failure.

fgetpos function C example:

  #include<stdio.h>

  #include<string.h>

  #include<errno.h>

  int main() {

        FILE *fp;

        char *str;

        fpos_t ptr;

        int val;

        fp = fopen("mastering-c.txt", "w");

        if (fp == NULL) {

                str =  strerror(errno);

                perror(str);

                return;

        }

        fgetpos(fp, &ptr);  // gets current position of file pointer

        fputs("Example for fgetpos...... this is the 1st line\n", fp);
        fputs("Example for fgetpos\n", fp);
        fputs("Example for fgetpos\n", fp

        printf("Do you want write at the beginning of the the file(0/1):");

        scanf("%d", &val);

        if(val == 1) {

                fsetpos(fp, &ptr); // sets current position of file pointer

                fputs("Writing at the beginning of the file\n", fp);

        } else if (val == 0) {

                fputs("Writing at the end of the file\n", fp);

        }

        fclose(fp);

        return 0;

  }

  Output:

  jp@jp-VirtualBox:~/cpgms/exp$ ./a.out

  Do you want write at the beginnig of the the file(0/1):0

  jp@jp-VirtualBox:~/cpgms/exp$ cat mastering-c.txt 
  Example for fgetpos...... this is the 1st line
  Example for fgetpos
  Example for fgetpos
  Writing at the end of the file

  jp@jp-VirtualBox:~/cpgms/exp$ ./a.out
  Do you want write at the beginnig of the the file(0/1):1

  jp@jp-VirtualBox:~/cpgms/exp$ cat mastering-c.txt 
  Writing at the beginning of the file
   1st line
  Example for fgetpos
  Example for fgetpos