C,C++ redirect and pipeline

[root@localhost ~]# cat t3.c | ./t3
start...
#include 
int main(int argc , char * argv[])
{
        char in[1024];
        int rlen = 0;
        printf("start...\n");
        do
        {
                rlen = fread(in , 1,sizeof(in),stdin);
                if(rlen> 0)
                {
                        printf("%s\n",in);
                }
        }while(rlen > 0);
        printf("end...\n");
        return 0;
}

end...
[root@localhost ~]# ./t3 < `echo t3.c`
start...
#include 
int main(int argc , char * argv[])
{
        char in[1024];
        int rlen = 0;
        printf("start...\n");
        do
        {
                rlen = fread(in , 1,sizeof(in),stdin);
                if(rlen> 0)
                {
                        printf("%s\n",in);
                }
        }while(rlen > 0);
        printf("end...\n");
        return 0;
}

end...
[root@localhost ~]# gcc -o t3 t3.c