#include	"call.h"#include	<poll.h>#define	BUFFSIZE	512/* * Copy everything from stdin to "remfd", * and everything from "remfd" to stdout. */voidloop(int remfd){	int				bol, n, nread;	char			c;	char			buff[BUFFSIZE];	struct pollfd	fds[2];	/*	 * Set stdout unbuffered for printfs in take() and put().	 */	setbuf(stdout, NULL);	fds[0].fd = STDIN_FILENO;	/* user's terminal input */	fds[0].events = POLLIN;	fds[1].fd = remfd;			/* input from remote (modem) */	fds[1].events = POLLIN;	for ( ; ; ) {		if (poll(fds, 2, -1) <= 0)			err_sys("poll error");		if (fds[0].revents & POLLIN) {	/* data to read on stdin */			if (read(STDIN_FILENO, &c, 1) != 1)				err_sys("read error from stdin");			if (c == escapec && bol) {				if ((n = doescape(remfd)) < 0)					break;		/* user wants to terminate */				else if (n == 0)					continue;	/* escape seq has been processed */				/* else char following escape wasn't special, */				/* so return and echo it below. */				c = n;			}			if (c == '\r' || c == '\n')				bol = 1;			else				bol = 0;			if (write(remfd, &c, 1) != 1)				err_sys("write error");		}		if (fds[0].revents & POLLHUP)			break;		/* stdin hangup -> done */		if (fds[1].revents & POLLIN) {	/* data to read from remote */			if ((nread = read(remfd, buff, BUFFSIZE)) <= 0)				break;		/* error or EOF, terminate */			if (writen(STDOUT_FILENO, buff, nread) != nread)				err_sys("writen error to stdout");		}		if (fds[1].revents & POLLHUP)			break;		/* modem hangup -> done */	}}