open,read and write problem

[*nix]

i am new to unix.
i have written a code for testing the basic functions
read / write and open

i have read that read/write returns the no of bytes read/written but
here my write is returning 1 and read is returning 0 no matter how many
chars i write.
could not rectify where is the problem
plz help me.

#include<stdio.h>
#include<fcntl.h>
int main()
{
        int fd , nob;
        char buf[30],rbuf[30];

        fd = open( "Ux1", O_CREAT| O_RDWR | O_TRUNC, 0777);
        if(fd<0)
        {       printf("cannot create file\n");
                exit(0);
        }
        printf(" fd =%d",fd);
        printf("Enter Sth\n");
        fgets(buf, sizeof(buf), stdin);
        if(nob = write ( fd , buf, sizeof(buf)) >  0)
        printf ( "%d bytes written \n",nob);
        nob = read (fd , rbuf, sizeof(rbuf))  ;
        printf ( "%d bytes read \n",nob);
        printf(" %s\n",rbuf);
        close(fd);
return 0;
}