1/*	$NetBSD: cl_read.c,v 1.2 2013/11/22 15:52:05 christos Exp $ */
2/*-
3 * Copyright (c) 1993, 1994
4 *	The Regents of the University of California.  All rights reserved.
5 * Copyright (c) 1993, 1994, 1995, 1996
6 *	Keith Bostic.  All rights reserved.
7 *
8 * See the LICENSE file for redistribution information.
9 */
10
11#include "config.h"
12
13#include <sys/cdefs.h>
14#if 0
15#ifndef lint
16static const char sccsid[] = "Id: cl_read.c,v 10.29 2001/08/18 21:51:59 skimo Exp  (Berkeley) Date: 2001/08/18 21:51:59 ";
17#endif /* not lint */
18#else
19__RCSID("$NetBSD$");
20#endif
21
22#include <sys/types.h>
23#include <sys/queue.h>
24#ifdef HAVE_SYS_SELECT_H
25#include <sys/select.h>
26#endif
27#include <sys/time.h>
28
29#include <bitstring.h>
30#include <errno.h>
31#include <fcntl.h>
32#include <signal.h>
33#include <stdio.h>
34#include <stdlib.h>
35#include <string.h>
36#include <termios.h>
37#include <unistd.h>
38
39#include "../common/common.h"
40#include "../ex/script.h"
41#include "cl.h"
42
43/* Pollution by Solaris curses. */
44#undef columns
45#undef lines
46
47static input_t	cl_read __P((SCR *,
48    u_int32_t, char *, size_t, int *, struct timeval *));
49static int	cl_resize __P((SCR *, size_t, size_t));
50
51/*
52 * cl_event --
53 *	Return a single event.
54 *
55 * PUBLIC: int cl_event __P((SCR *, EVENT *, u_int32_t, int));
56 */
57int
58cl_event(SCR *sp, EVENT *evp, u_int32_t flags, int ms)
59{
60	struct timeval t, *tp;
61	CL_PRIVATE *clp;
62	size_t lines, columns;
63	int changed, nr = 0;
64	const CHAR_T *wp;
65	size_t wlen;
66	int rc;
67
68	/*
69	 * Queue signal based events.  We never clear SIGHUP or SIGTERM events,
70	 * so that we just keep returning them until the editor dies.
71	 */
72	clp = CLP(sp);
73retest:	if (LF_ISSET(EC_INTERRUPT) || F_ISSET(clp, CL_SIGINT)) {
74		if (F_ISSET(clp, CL_SIGINT)) {
75			F_CLR(clp, CL_SIGINT);
76			evp->e_event = E_INTERRUPT;
77		} else
78			evp->e_event = E_TIMEOUT;
79		return (0);
80	}
81	if (F_ISSET(clp, CL_SIGHUP | CL_SIGTERM | CL_SIGWINCH)) {
82		if (F_ISSET(clp, CL_SIGHUP)) {
83			evp->e_event = E_SIGHUP;
84			return (0);
85		}
86		if (F_ISSET(clp, CL_SIGTERM)) {
87			evp->e_event = E_SIGTERM;
88			return (0);
89		}
90		if (F_ISSET(clp, CL_SIGWINCH)) {
91			F_CLR(clp, CL_SIGWINCH);
92			if (cl_ssize(sp, 1, &lines, &columns, &changed))
93				return (1);
94			if (changed) {
95				(void)cl_resize(sp, lines, columns);
96				evp->e_event = E_WRESIZE;
97				return (0);
98			}
99			/* No real change, ignore the signal. */
100		}
101	}
102
103	/* Set timer. */
104	if (ms == 0)
105		tp = NULL;
106	else {
107		t.tv_sec = ms / 1000;
108		t.tv_usec = (ms % 1000) * 1000;
109		tp = &t;
110	}
111
112	/* Read input characters. */
113read:
114	switch (cl_read(sp, LF_ISSET(EC_QUOTED | EC_RAW),
115	    clp->ibuf + clp->skip, SIZE(clp->ibuf) - clp->skip, &nr, tp)) {
116	case INP_OK:
117		rc = INPUT2INT5(sp, clp->cw, clp->ibuf, nr + clp->skip,
118				wp, wlen);
119		evp->e_csp = __UNCONST(wp);
120		evp->e_len = wlen;
121		evp->e_event = E_STRING;
122		if (rc < 0) {
123		    int n = -rc;
124		    memmove(clp->ibuf, clp->ibuf + nr + clp->skip - n, n);
125		    clp->skip = n;
126		    if (wlen == 0)
127			goto read;
128		} else if (rc == 0)
129		    clp->skip = 0;
130		else
131		    msgq(sp, M_ERR, "323|Invalid input. Truncated.");
132		break;
133	case INP_ERR:
134		evp->e_event = E_ERR;
135		break;
136	case INP_EOF:
137		evp->e_event = E_EOF;
138		break;
139	case INP_INTR:
140		goto retest;
141	case INP_TIMEOUT:
142		evp->e_event = E_TIMEOUT;
143		break;
144	default:
145		abort();
146	}
147	return (0);
148}
149
150/*
151 * cl_read --
152 *	Read characters from the input.
153 */
154static input_t
155cl_read(SCR *sp, u_int32_t flags, char *bp, size_t blen, int *nrp, struct timeval *tp)
156{
157	struct termios term1, term2;
158	struct timeval poll;
159	CL_PRIVATE *clp;
160	GS *gp;
161	fd_set rdfd;
162	input_t rval;
163	int maxfd, nr, term_reset;
164
165	gp = sp->gp;
166	clp = CLP(sp);
167	term_reset = 0;
168
169	/*
170	 * 1: A read from a file or a pipe.  In this case, the reads
171	 *    never timeout regardless.  This means that we can hang
172	 *    when trying to complete a map, but we're going to hang
173	 *    on the next read anyway.
174	 */
175	if (!F_ISSET(clp, CL_STDIN_TTY)) {
176		switch (nr = read(STDIN_FILENO, bp, blen)) {
177		case 0:
178			return (INP_EOF);
179		case -1:
180			goto err;
181		default:
182			*nrp = nr;
183			return (INP_OK);
184		}
185		/* NOTREACHED */
186	}
187
188	/*
189	 * 2: A read with an associated timeout, e.g., trying to complete
190	 *    a map sequence.  If input exists, we fall into #3.
191	 */
192	FD_ZERO(&rdfd);
193	poll.tv_sec = 0;
194	poll.tv_usec = 0;
195	if (tp != NULL) {
196		FD_SET(STDIN_FILENO, &rdfd);
197		switch (select(STDIN_FILENO + 1,
198		    &rdfd, NULL, NULL, tp == NULL ? &poll : tp)) {
199		case 0:
200			return (INP_TIMEOUT);
201		case -1:
202			goto err;
203		default:
204			break;
205		}
206	}
207
208	/*
209	 * The user can enter a key in the editor to quote a character.  If we
210	 * get here and the next key is supposed to be quoted, do what we can.
211	 * Reset the tty so that the user can enter a ^C, ^Q, ^S.  There's an
212	 * obvious race here, when the key has already been entered, but there's
213	 * nothing that we can do to fix that problem.
214	 *
215	 * The editor can ask for the next literal character even thought it's
216	 * generally running in line-at-a-time mode.  Do what we can.
217	 */
218	if (LF_ISSET(EC_QUOTED | EC_RAW) && !tcgetattr(STDIN_FILENO, &term1)) {
219		term_reset = 1;
220		if (LF_ISSET(EC_QUOTED)) {
221			term2 = term1;
222			term2.c_lflag &= ~ISIG;
223			term2.c_iflag &= ~(IXON | IXOFF);
224			(void)tcsetattr(STDIN_FILENO,
225			    TCSASOFT | TCSADRAIN, &term2);
226		} else
227			(void)tcsetattr(STDIN_FILENO,
228			    TCSASOFT | TCSADRAIN, &clp->vi_enter);
229	}
230
231	/*
232	 * 3: Wait for input.
233	 *
234	 * Select on the command input and scripting window file descriptors.
235	 * It's ugly that we wait on scripting file descriptors here, but it's
236	 * the only way to keep from locking out scripting windows.
237	 */
238	if (F_ISSET(gp, G_SCRWIN)) {
239		FD_ZERO(&rdfd);
240		FD_SET(STDIN_FILENO, &rdfd);
241		maxfd = STDIN_FILENO;
242		if (sscr_check_input(sp, &rdfd, maxfd))
243			goto err;
244	}
245
246	/*
247	 * 4: Read the input.
248	 *
249	 * !!!
250	 * What's going on here is some scary stuff.  Ex runs the terminal in
251	 * canonical mode.  So, the <newline> character terminating a line of
252	 * input is returned in the buffer, but a trailing <EOF> character is
253	 * not similarly included.  As ex uses 0<EOF> and ^<EOF> as autoindent
254	 * commands, it has to see the trailing <EOF> characters to determine
255	 * the difference between the user entering "0ab" and "0<EOF>ab".  We
256	 * leave an extra slot in the buffer, so that we can add a trailing
257	 * <EOF> character if the buffer isn't terminated by a <newline>.  We
258	 * lose if the buffer is too small for the line and exactly N characters
259	 * are entered followed by an <EOF> character.
260	 */
261#define	ONE_FOR_EOF	1
262	switch (nr = read(STDIN_FILENO, bp, blen - ONE_FOR_EOF)) {
263	case  0:				/* EOF. */
264		/*
265		 * ^D in canonical mode returns a read of 0, i.e. EOF.  EOF is
266		 * a valid command, but we don't want to loop forever because
267		 * the terminal driver is returning EOF because the user has
268		 * disconnected. The editor will almost certainly try to write
269		 * something before this fires, which should kill us, but You
270		 * Never Know.
271		 */
272		if (++clp->eof_count < 50) {
273			bp[0] = clp->orig.c_cc[VEOF];
274			*nrp = 1;
275			rval = INP_OK;
276
277		} else
278			rval = INP_EOF;
279		break;
280	case -1:				/* Error or interrupt. */
281err:		if (errno == EINTR)
282			rval = INP_INTR;
283		else {
284			rval = INP_ERR;
285			msgq(sp, M_SYSERR, "input");
286		}
287		break;
288	default:				/* Input characters. */
289		if (F_ISSET(sp, SC_EX) && bp[nr - 1] != '\n')
290			bp[nr++] = clp->orig.c_cc[VEOF];
291		*nrp = nr;
292		clp->eof_count = 0;
293		rval = INP_OK;
294		break;
295	}
296
297	/* Restore the terminal state if it was modified. */
298	if (term_reset)
299		(void)tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &term1);
300	return (rval);
301}
302
303/*
304 * cl_resize --
305 *	Reset the options for a resize event.
306 */
307static int
308cl_resize(SCR *sp, size_t lines, size_t columns)
309{
310	int rval;
311
312	rval = api_opts_set(sp, L("lines"), NULL, lines, 0);
313	if (api_opts_set(sp, L("columns"), NULL, columns, 0))
314		rval = 1;
315	return (rval);
316}
317