#define BLEN 512

struct iob {
	int fd;		/*file descriptor*/
	int cc;		/*char count*/
	char *cp;	/*ptr to next char*/
	char cbuf[BLEN];	/*char buffer*/
} fin;

getchar()
{
	char c;
	register int i;

	if(fin.fd==0) {
		if(read(0,&c,1)<=0 || c==4)
			return(0);
		i = c;
		return(i&0xff);
	}
	if(fin.cc<=0) {
		fin.cp = &(fin.cbuf[0]);
		fin.cc = read(fin.fd,fin.cp,BLEN);
	}
	if(fin.cc <= 0) {
		return(0);
	}
	fin.cc--;
	i = *(fin.cp)++;
	return(i&0xff);
}