tty.c

举世闻名的joe记事本源程序

/*
 *	UNIX Tty and Process interface
 *	Copyright
 *		(C) 1992 Joseph H. Allen
 *
 *	This file is part of JOE (Joe's Own Editor)
 */
#include "types.h"

#ifdef GWINSZ_IN_SYS_IOCTL
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#endif
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif

#ifdef HAVE_OPENPTY

#ifdef HAVE_PTY_H
#include <pty.h>
#endif

#ifdef HAVE_LIBUTIL_H
#include <libutil.h>
#endif

#endif

#ifdef HAVE_LOGIN_TTY
#ifdef HAVE_UTMP_H
#include <utmp.h>
#endif
#endif

int idleout = 1;

#ifdef __amigaos
#undef SIGTSTP
#endif

/* We use the defines in sys/ioctl to determine what type
 * tty interface the system uses and what type of system
 * we actually have.
 */
#ifdef HAVE_POSIX_TERMIOS
#  include <termios.h>
#else
#  ifdef HAVE_SYSV_TERMIO
#    include <termio.h>
#    include <sys/termio.h>
#  else
#    include <sgtty.h>
#  endif
#endif

#ifdef HAVE_SETITIMER
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#endif

/* I'm not sure if SCO_UNIX and ISC have __svr4__ defined, but I think
   they might */
#ifdef M_SYS5
#ifndef M_XENIX
#include <sys/stream.h>
#include <sys/ptem.h>
#ifndef __svr4__
#define __svr4__ 1
#endif
#endif
#endif

#ifdef ISC
#ifndef __svr4__
#define __svr4__ 1
#endif
#endif

#ifdef __svr4__
#include <stropts.h>
#endif

/** Aliased defines **/

/* O_NDELAY, O_NONBLOCK, and FNDELAY are all synonyms for placing a descriptor
 * in non-blocking mode; we make whichever one we have look like O_NDELAY
 */
#ifndef O_NDELAY
#ifdef O_NONBLOCK
#define O_NDELAY O_NONBLOCK
#endif
#ifdef FNDELAY
#define O_NDELAY FNDELAY
#endif
#endif

/* Some systems define this, some don't */
#ifndef sigmask
#define sigmask(x) (1<<((x)-1))
#endif

/* Some BSDs don't have TILDE */
#ifndef TILDE
#define TILDE 0
#endif

/* Global configuration variables */

int noxon = 0;			/* Set if ^S/^Q processing should be disabled */
int Baud = 0;			/* Baud rate from joerc, cmd line or environment */

/* The terminal */

FILE *termin = NULL;
FILE *termout = NULL;

/* Original state of tty */

#ifdef HAVE_POSIX_TERMIOS
struct termios oldterm;
#else /* HAVE_POSIX_TERMIOS */
#ifdef HAVE_SYSV_TERMIO
static struct termio oldterm;
#else /* HAVE_SYSV_TERMIO */
static struct sgttyb oarg;
static struct tchars otarg;
static struct ltchars oltarg;
#endif /* HAVE_SYSV_TERMIO */
#endif /* HAVE_POSIX_TERMIOS */

/* Output buffer, index and size */

unsigned char *obuf = NULL;
int obufp = 0;
int obufsiz;

/* The baud rate */

unsigned baud;			/* Bits per second */
unsigned long upc;		/* Microseconds per character */

/* TTY Speed code to baud-rate conversion table (this is dumb- is it really
 * too much to ask for them to just use an integer for the baud-rate?)
 */

static int speeds[] = {
	B50, 50, B75, 75, B110, 110, B134, 134, B150, 150, B200, 200, B300,
	300, B600, 600,
	B1200, 1200, B1800, 1800, B2400, 2400, B4800, 4800, B9600, 9600
#ifdef EXTA
	    , EXTA, 19200
#endif
#ifdef EXTB
	    , EXTB, 38400
#endif
#ifdef B19200
	    , B19200, 19200
#endif
#ifdef B38400
	    , B38400, 38400
#endif
};

/* Input buffer */

int have = 0;			/* Set if we have pending input */
static unsigned char havec;	/* Character read in during pending input check */
int leave = 0;			/* When set, typeahead checking is disabled */

/* TTY mode flag.  1 for open, 0 for closed */
static int ttymode = 0;

/* Signal state flag.  1 for joe, 0 for normal */
static int ttysig = 0;

/* Stuff for shell windows */

static pid_t kbdpid;		/* PID of kbd client */
static int ackkbd = -1;		/* Editor acks keyboard client to this */

static int mpxfd;		/* Editor reads packets from this fd */
static int mpxsfd;		/* Clients send packets to this fd */

static int nmpx = 0;
static int accept = NO_MORE_DATA;	/* =-1 if we have last packet */

struct packet {
	MPX *who;
	int size;
	int ch;
	unsigned char data[1024];
} pack;

MPX asyncs[NPROC];

/* Set signals for JOE */
void sigjoe(void)
{
	if (ttysig)
		return;
	ttysig = 1;
	joe_set_signal(SIGHUP, ttsig);
	joe_set_signal(SIGTERM, ttsig);
	joe_set_signal(SIGABRT, ttsig);
	joe_set_signal(SIGINT, SIG_IGN);
	joe_set_signal(SIGPIPE, SIG_IGN);
}

/* Restore signals for exiting */
void signrm(void)
{
	if (!ttysig)
		return;
	ttysig = 0;
	joe_set_signal(SIGABRT, SIG_DFL);
	joe_set_signal(SIGHUP, SIG_DFL);
	joe_set_signal(SIGTERM, SIG_DFL);
	joe_set_signal(SIGINT, SIG_DFL);
	joe_set_signal(SIGPIPE, SIG_DFL);
}

/* Open terminal and set signals */

void ttopen(void)
{
	sigjoe();
	ttopnn();
}

/* Close terminal and restore signals */

void ttclose(void)
{
	ttclsn();
	signrm();
}

static int winched = 0;
#ifdef SIGWINCH
/* Window size interrupt handler */
static RETSIGTYPE winchd(int unused)
{
	++winched;
	REINSTALL_SIGHANDLER(SIGWINCH, winchd);
}
#endif

/* Second ticker */

int ticked = 0;
static RETSIGTYPE dotick(int unused)
{
	ticked = 1;
}

void tickoff(void)
{
#ifdef HAVE_SETITIMER
	struct itimerval val;
	val.it_value.tv_sec = 0;
	val.it_value.tv_usec = 0;
	val.it_interval.tv_sec = 0;
	val.it_interval.tv_usec = 0;
	setitimer(ITIMER_REAL,&val,NULL);
#else
	alarm(0);
#endif
}

void tickon(void)
{
#ifdef HAVE_SETITIMER
	struct itimerval val;
	val.it_interval.tv_sec = 0;
	val.it_interval.tv_usec = 0;
	if (auto_scroll) {
		int tim = auto_trig_time - mnow();
		if (tim < 0)
			tim = 1;
		tim *= 1000;
		val.it_value.tv_sec = 0;
		val.it_value.tv_usec = tim;
	} else {
		val.it_value.tv_sec = 1;
		val.it_value.tv_usec = 0;
	}
	ticked = 0;
	joe_set_signal(SIGALRM, dotick);
	setitimer(ITIMER_REAL,&val,NULL);
#else
	ticked = 0;
	joe_set_signal(SIGALRM, dotick);
	alarm(1);
#endif
}

/* Open terminal */

void ttopnn(void)
{
	int x, bbaud;

#ifdef HAVE_POSIX_TERMIOS
	struct termios newterm;
#else
#ifdef HAVE_SYSV_TERMIO
	struct termio newterm;
#else
	struct sgttyb arg;
	struct tchars targ;
	struct ltchars ltarg;
#endif
#endif

	if (!termin) {
		if (idleout ? (!(termin = stdin) || !(termout = stdout)) : (!(termin = fopen("/dev/tty", "r")) || !(termout = fopen("/dev/tty", "w")))) {
			fprintf(stderr, (char *)joe_gettext(_("Couldn\'t open /dev/tty\n")));
			exit(1);
		} else {
#ifdef SIGWINCH
			joe_set_signal(SIGWINCH, winchd);
#endif
		}
	}

	if (ttymode)
		return;
	ttymode = 1;
	fflush(termout);

#ifdef HAVE_POSIX_TERMIOS
	tcgetattr(fileno(termin), &oldterm);
	newterm = oldterm;
	newterm.c_lflag = 0;
	if (noxon)
		newterm.c_iflag &= ~(ICRNL | IGNCR | INLCR | IXON | IXOFF);
	else
		newterm.c_iflag &= ~(ICRNL | IGNCR | INLCR);
	newterm.c_oflag = 0;
	newterm.c_cc[VMIN] = 1;
	newterm.c_cc[VTIME] = 0;
	tcsetattr(fileno(termin), TCSADRAIN, &newterm);
	bbaud = cfgetospeed(&newterm);
#else
#ifdef HAVE_SYSV_TERMIO
	ioctl(fileno(termin), TCGETA, &oldterm);
	newterm = oldterm;
	newterm.c_lflag = 0;
	if (noxon)
		newterm.c_iflag &= ~(ICRNL | IGNCR | INLCR | IXON | IXOFF);
	else
		newterm.c_iflag &= ~(ICRNL | IGNCR | INLCR);
	newterm.c_oflag = 0;
	newterm.c_cc[VMIN] = 1;
	newterm.c_cc[VTIME] = 0;
	ioctl(fileno(termin), TCSETAW, &newterm);
	bbaud = (newterm.c_cflag & CBAUD);
#else
	ioctl(fileno(termin), TIOCGETP, &arg);
	ioctl(fileno(termin), TIOCGETC, &targ);
	ioctl(fileno(termin), TIOCGLTC, &ltarg);
	oarg = arg;
	otarg = targ;
	oltarg = ltarg;
	arg.sg_flags = ((arg.sg_flags & ~(ECHO | CRMOD | XTABS | ALLDELAY | TILDE)) | CBREAK);
	if (noxon) {
		targ.t_startc = -1;
		targ.t_stopc = -1;
	}
	targ.t_intrc = -1;
	targ.t_quitc = -1;
	targ.t_eofc = -1;
	targ.t_brkc = -1;
	ltarg.t_suspc = -1;
	ltarg.t_dsuspc = -1;
	ltarg.t_rprntc = -1;
	ltarg.t_flushc = -1;
	ltarg.t_werasc = -1;
	ltarg.t_lnextc = -1;
	ioctl(fileno(termin), TIOCSETN, &arg);
	ioctl(fileno(termin), TIOCSETC, &targ);
	ioctl(fileno(termin), TIOCSLTC, &ltarg);
	bbaud = arg.sg_ospeed;
#endif
#endif

	baud = 9600;
	upc = 0;
	for (x = 0; x != 30; x += 2)
		if (bbaud == speeds[x]) {
			baud = speeds[x + 1];
			break;
		}
	if (Baud)
		baud = Baud;
	upc = DIVIDEND / baud;
	if (obuf)
		joe_free(obuf);
	if (!(TIMES * upc))
		obufsiz = 4096;
	else {
		obufsiz = 1000000 / (TIMES * upc);
		if (obufsiz > 4096)
			obufsiz = 4096;
	}
	if (!obufsiz)
		obufsiz = 1;
	obuf = (unsigned char *) joe_malloc(obufsiz);
}

/* Close terminal */

void ttclsn(void)
{
	int oleave;

	if (ttymode)
		ttymode = 0;
	else
		return;

	oleave = leave;
	leave = 1;

	ttflsh();

#ifdef HAVE_POSIX_TERMIOS
	tcsetattr(fileno(termin), TCSADRAIN, &oldterm);
#else
#ifdef HAVE_SYSV_TERMIO
	ioctl(fileno(termin), TCSETAW, &oldterm);
#else
	ioctl(fileno(termin), TIOCSETN, &oarg);
	ioctl(fileno(termin), TIOCSETC, &otarg);
	ioctl(fileno(termin), TIOCSLTC, &oltarg);
#endif
#endif

	leave = oleave;
}

/* Timer interrupt handler */

static int yep;
static RETSIGTYPE dosig(int unused)
{
	yep = 1;
}

/* FLush output and check for typeahead */

#ifdef HAVE_SETITIMER
#ifdef SIG_SETMASK
static void maskit(void)
{
	sigset_t set;

	sigemptyset(&set);
	sigaddset(&set, SIGALRM);
	sigprocmask(SIG_SETMASK, &set, NULL);
}

static void unmaskit(void)
{
	sigset_t set;

	sigemptyset(&set);
	sigprocmask(SIG_SETMASK, &set, NULL);
}

static void pauseit(void)
{
	sigset_t set;

	sigemptyset(&set);
	sigsuspend(&set);
}

#else
static void maskit(void)
{
	sigsetmask(sigmask(SIGALRM));
}

static void unmaskit(void)
{
	sigsetmask(0);
}

static void pauseit(void)
{
	sigpause(0);
}

#endif
#endif

int ttflsh(void)
{
	/* Flush output */
	if (obufp) {
		unsigned long usec = obufp * upc;	/* No. usecs this write should take */

#ifdef HAVE_SETITIMER
		if (usec >= 50000 && baud < 9600) {
			struct itimerval a, b;

			a.it_value.tv_sec = usec / 1000000;
			a.it_value.tv_usec = usec % 1000000;
			a.it_interval.tv_usec = 0;
			a.it_interval.tv_sec = 0;
			alarm(0);
			joe_set_signal(SIGALRM, dosig);
			yep = 0;
			maskit();
			setitimer(ITIMER_REAL, &a, &b);
			joe_write(fileno(termout), obuf, obufp);
			while (!yep)
				pauseit();
			unmaskit();
		} else
			joe_write(fileno(termout), obuf, obufp);

#else

		joe_write(fileno(termout), obuf, obufp);

#ifdef FIORDCHK
		if (baud < 9600 && usec / 1000)
			nap(usec / 1000);
#endif

#endif

		obufp = 0;
	}

	/* Ack previous packet */
	if (ackkbd != -1 && accept != NO_MORE_DATA && !have) {
		unsigned char c = 0;

		if (pack.who && pack.who->func)
			joe_write(pack.who->ackfd, &c, 1);
		else
			joe_write(ackkbd, &c, 1);
		accept = NO_MORE_DATA;
	}

	/* Check for typeahead or next packet */

	if (!have && !leave) {
		if (ackkbd != -1) {
			fcntl(mpxfd, F_SETFL, O_NDELAY);
			if (read(mpxfd, &pack, sizeof(struct packet) - 1024) > 0) {
				fcntl(mpxfd, F_SETFL, 0);
				joe_read(mpxfd, pack.data, pack.size);
				have = 1;
				accept = pack.ch;
			} else
				fcntl(mpxfd, F_SETFL, 0);
		} else {
			/* Set terminal input to non-blocking */
			fcntl(fileno(termin), F_SETFL, O_NDELAY);

			/* Try to read */
			if (read(fileno(termin), &havec, 1) == 1)
				have = 1;

			/* Set terminal back to blocking */
			fcntl(fileno(termin), F_SETFL, 0);
		}
	}
	return 0;
}

/* Read next character from input */

void mpxdied(MPX *m);

long last_time;

int ttgetc(void)
{
	int stat;
	long new_time;
	int flg;


	tickon();

      loop:
      	flg = 0;
      	/* Status line clock */
	new_time = time(NULL);
	if (new_time != last_time) {
		last_time = new_time;
		dostaupd = 1;
		ticked = 1;
	}
	/* Autoscroller */
	if (auto_scroll && mnow() >= auto_trig_time) {
		do_auto_scroll();
		ticked = 1;
		flg = 1;
	}
	ttflsh();
	while (winched) {
		winched = 0;
		edupd(1);
		ttflsh();
	}
	if (ticked) {
		edupd(flg);
		ttflsh();
		tickon();