#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/signal.h>
#include <sys/errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <termios.h>
extern FILE *scrfp;
extern char scrname[];
extern struct termios oldtty;
extern char t_flushc, t_intrc, t_quitc, sg_erase, sg_kill;
extern int errno;
int errexit(const char *format, ...), cerrexit(const char *format, ...);
int ttwrite(FILE *sfp, FILE *tfp, unsigned char *buf, int cc);
int sowrite(FILE *sfp, FILE *tfp, unsigned char *buf, int cc);
int fsmbuild(void);
void rcvurg(int);
#define BUFSIZE 2048
struct termios oldtty;
int connectTCP(const char *host, const char *service);
int ttysetup(void);
int telnet(const char *host, const char *service) {
int s, nfds;
u_char buf[BUFSIZE];
int cc;
int on = 1;
fd_set arfds, awfds, rfds, wfds;
FILE *sfp;
s = connectTCP(host, service);
ttysetup();
fsmbuild();
(void) signal(SIGURG, rcvurg);
(void) setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (char *)&on, sizeof(on));
nfds = getdtablesize();
FD_ZERO(&arfds);
FD_ZERO(&awfds);
FD_SET(s, &arfds);
FD_SET(0, &arfds);
sfp = fdopen(s, "w");
while (1) { memcpy(&rfds, &arfds, sizeof(rfds));
memcpy(&wfds, &awfds, sizeof(rfds));
if (select(nfds, &rfds, &wfds, (fd_set *)0,
(struct timeval *)0) < 0) { if (errno == EINTR)
continue;
cerrexit("select: %s\n", strerror(errno)); }
if (FD_ISSET(s, &rfds)) { cc = read(s, (char *)buf, sizeof(buf));
if (cc < 0)
cerrexit("socket read: %s\n", strerror(errno));
else if (cc == 0) { printf("\nconnection closed.\n"); if (tcsetattr(0, TCSADRAIN, &oldtty) < 0)
errexit("tcsetattr: %s\n", strerror(errno));
exit(0);
} else
ttwrite(sfp, stdout, buf, cc);
}
if (FD_ISSET(0, &rfds)) { cc = read(0, (char *)buf, sizeof(buf));
if (cc < 0)
cerrexit("tty read: %s\n", strerror(errno));
else if (cc == 0) { FD_CLR(0, &arfds);
(void) shutdown(s, 1);
} else
sowrite(sfp, stdout, buf, cc);
}
(void) fflush(sfp);
(void) fflush(stdout);
}
}
