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rcsid[] and sccsid[] and copyright[] are essentially unmaintained (and
unmaintainable).  these days, people use source.  these id's do not provide
any benefit, and do hurt the small install media
(the 33,000 line diff is essentially mechanical)
ok with the idea millert, ok dms

/*	$OpenBSD: cl_read.c,v 1.18 2009/10/27 23:59:47 deraadt Exp $	*/

/*-
 * Copyright (c) 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1993, 1994, 1995, 1996
 *	Keith Bostic.  All rights reserved.
 *
 * See the LICENSE file for redistribution information.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/time.h>

#include <bitstring.h>
#include <curses.h>
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>

#include "../common/common.h"
#include "../ex/script.h"
#include "cl.h"

static input_t	cl_read(SCR *,
		    u_int32_t, CHAR_T *, size_t, int *, struct timeval *);
static int	cl_resize(SCR *, size_t, size_t);

/*
 * cl_event --
 *	Return a single event.
 *
 * PUBLIC: int cl_event(SCR *, EVENT *, u_int32_t, int);
 */
int
cl_event(sp, evp, flags, ms)
	SCR *sp;
	EVENT *evp;
	u_int32_t flags;
	int ms;
{
	struct timeval t, *tp;
	CL_PRIVATE *clp;
	size_t lines, columns;
	int changed, nr;

	/*
	 * Queue signal based events.  We never clear SIGHUP or SIGTERM events,
	 * so that we just keep returning them until the editor dies.
	 */
	clp = CLP(sp);
retest:	if (LF_ISSET(EC_INTERRUPT) || F_ISSET(clp, CL_SIGINT)) {
		if (F_ISSET(clp, CL_SIGINT)) {
			F_CLR(clp, CL_SIGINT);
			evp->e_event = E_INTERRUPT;
		} else
			evp->e_event = E_TIMEOUT;
		return (0);
	}
	if (F_ISSET(clp, CL_SIGHUP | CL_SIGTERM | CL_SIGWINCH)) {
		if (F_ISSET(clp, CL_SIGHUP)) {
			evp->e_event = E_SIGHUP;
			return (0);
		}
		if (F_ISSET(clp, CL_SIGTERM)) {
			evp->e_event = E_SIGTERM;
			return (0);
		}
		if (F_ISSET(clp, CL_SIGWINCH)) {
			F_CLR(clp, CL_SIGWINCH);
			if (cl_ssize(sp, 1, &lines, &columns, &changed))
				return (1);
			if (changed) {
				(void)cl_resize(sp, lines, columns);
				evp->e_event = E_WRESIZE;
				return (0);
			}
			/* No real change, ignore the signal. */
		}
	}

	/* Set timer. */
	if (ms == 0)
		tp = NULL;
	else {
		t.tv_sec = ms / 1000;
		t.tv_usec = (ms % 1000) * 1000;
		tp = &t;
	}

	/* Read input characters. */
	switch (cl_read(sp, LF_ISSET(EC_QUOTED | EC_RAW),
	    clp->ibuf, sizeof(clp->ibuf), &nr, tp)) {
	case INP_OK:
		evp->e_csp = clp->ibuf;
		evp->e_len = nr;
		evp->e_event = E_STRING;
		break;
	case INP_EOF:
		evp->e_event = E_EOF;
		break;
	case INP_ERR:
		evp->e_event = E_ERR;
		break;
	case INP_INTR:
		goto retest;
	case INP_TIMEOUT:
		evp->e_event = E_TIMEOUT;
		break;
	default:
		abort();
	}
	return (0);
}

/*
 * cl_read --
 *	Read characters from the input.
 */
static input_t
cl_read(sp, flags, bp, blen, nrp, tp)
	SCR *sp;
	u_int32_t flags;
	CHAR_T *bp;
	size_t blen;
	int *nrp;
	struct timeval *tp;
{
	struct termios term1, term2;
	CL_PRIVATE *clp;
	GS *gp;
	struct pollfd pfd[1];
	input_t rval;
	int nr, term_reset, timeout;

	gp = sp->gp;
	clp = CLP(sp);
	term_reset = 0;

	/*
	 * 1: A read from a file or a pipe.  In this case, the reads
	 *    never timeout regardless.  This means that we can hang
	 *    when trying to complete a map, but we're going to hang
	 *    on the next read anyway.
	 */
	if (!F_ISSET(clp, CL_STDIN_TTY)) {
		switch (nr = read(STDIN_FILENO, bp, blen)) {
		case 0:
			return (INP_EOF);
		case -1:
			goto err;
		default:
			*nrp = nr;
			return (INP_OK);
		}
		/* NOTREACHED */
	}

	/*
	 * 2: A read with an associated timeout, e.g., trying to complete
	 *    a map sequence.  If input exists, we fall into #3.
	 */
tty_retry:
	if (tp != NULL) {
		pfd[0].fd = STDIN_FILENO;
		pfd[0].events = POLLIN;
		timeout = tp ? (tp->tv_sec * 1000) + (tp->tv_usec / 1000) : 0;
		switch (poll(pfd, 1, timeout)) {
		case 0:
			return (INP_TIMEOUT);
		case -1:
			goto err;
		default:
			break;
		}
	}
	
	/*
	 * The user can enter a key in the editor to quote a character.  If we
	 * get here and the next key is supposed to be quoted, do what we can.
	 * Reset the tty so that the user can enter a ^C, ^Q, ^S.  There's an
	 * obvious race here, when the key has already been entered, but there's
	 * nothing that we can do to fix that problem.
	 *
	 * The editor can ask for the next literal character even thought it's
	 * generally running in line-at-a-time mode.  Do what we can.
	 */
	if (LF_ISSET(EC_QUOTED | EC_RAW) && !tcgetattr(STDIN_FILENO, &term1)) {
		term_reset = 1;
		if (LF_ISSET(EC_QUOTED)) {
			term2 = term1;
			term2.c_lflag &= ~ISIG;
			term2.c_iflag &= ~(IXON | IXOFF);
			(void)tcsetattr(STDIN_FILENO,
			    TCSASOFT | TCSADRAIN, &term2);
		} else
			(void)tcsetattr(STDIN_FILENO,
			    TCSASOFT | TCSADRAIN, &clp->vi_enter);
	}

	/*
	 * 3: Wait for input.
	 *
	 * Select on the command input and scripting window file descriptors.
	 * It's ugly that we wait on scripting file descriptors here, but it's
	 * the only way to keep from locking out scripting windows.
	 */
	if (F_ISSET(gp, G_SCRWIN)) {
		if (sscr_check_input(sp))
			goto err;
	}

	/*
	 * 4: Read the input.
	 *
	 * !!!
	 * What's going on here is some scary stuff.  Ex runs the terminal in
	 * canonical mode.  So, the <newline> character terminating a line of
	 * input is returned in the buffer, but a trailing <EOF> character is
	 * not similarly included.  As ex uses 0<EOF> and ^<EOF> as autoindent
	 * commands, it has to see the trailing <EOF> characters to determine
	 * the difference between the user entering "0ab" and "0<EOF>ab".  We
	 * leave an extra slot in the buffer, so that we can add a trailing
	 * <EOF> character if the buffer isn't terminated by a <newline>.  We
	 * lose if the buffer is too small for the line and exactly N characters
	 * are entered followed by an <EOF> character.
	 */
#define	ONE_FOR_EOF	1
	switch (nr = read(STDIN_FILENO, bp, blen - ONE_FOR_EOF)) {
	case  0:				/* EOF. */
		/*
		 * ^D in canonical mode returns a read of 0, i.e. EOF.  EOF is
		 * a valid command, but we don't want to loop forever because
		 * the terminal driver is returning EOF because the user has
		 * disconnected. The editor will almost certainly try to write
		 * something before this fires, which should kill us, but You
		 * Never Know.
		 */
		if (++clp->eof_count < 50) {
			bp[0] = clp->orig.c_cc[VEOF];
			*nrp = 1;
			rval = INP_OK;

		} else
			rval = INP_EOF;
		break;
	case -1:				/* Error or interrupt. */
err:		if (errno == EINTR)
			rval = INP_INTR;
		else if (errno == EAGAIN)
			goto tty_retry;
		else {
			rval = INP_ERR;
			msgq(sp, M_SYSERR, "input");
		}
		break;
	default:				/* Input characters. */
		if (F_ISSET(sp, SC_EX) && bp[nr - 1] != '\n')
			bp[nr++] = clp->orig.c_cc[VEOF];
		*nrp = nr;
		clp->eof_count = 0;
		rval = INP_OK;
		break;
	}

	/* Restore the terminal state if it was modified. */
	if (term_reset)
		(void)tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &term1);
	return (rval);
}

/* 
 * cl_resize --
 *	Reset the options for a resize event.
 */
static int
cl_resize(sp, lines, columns)
	SCR *sp;
	size_t lines, columns;
{
	ARGS *argv[2], a, b;
	char b1[1024];

	a.bp = b1;
	b.bp = NULL;
	a.len = b.len = 0;
	argv[0] = &a;
	argv[1] = &b;

	(void)snprintf(b1, sizeof(b1), "lines=%lu", (u_long)lines);
	a.len = strlen(b1);
	if (opts_set(sp, argv, NULL))
		return (1);
	(void)snprintf(b1, sizeof(b1), "columns=%lu", (u_long)columns);
	a.len = strlen(b1);
	if (opts_set(sp, argv, NULL))
		return (1);
	return (0);
}