xref: /freebsd/contrib/nvi/cl/cl_read.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
1 /*-
2  * Copyright (c) 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1993, 1994, 1995, 1996
5  *	Keith Bostic.  All rights reserved.
6  *
7  * See the LICENSE file for redistribution information.
8  */
9 
10 #include "config.h"
11 
12 #ifndef lint
13 static const char sccsid[] = "@(#)cl_read.c	10.15 (Berkeley) 9/24/96";
14 #endif /* not lint */
15 
16 #include <sys/types.h>
17 #include <sys/queue.h>
18 #ifdef HAVE_SYS_SELECT_H
19 #include <sys/select.h>
20 #endif
21 #include <sys/time.h>
22 
23 #include <bitstring.h>
24 #include <curses.h>
25 #include <errno.h>
26 #include <fcntl.h>
27 #include <signal.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <termios.h>
32 #include <unistd.h>
33 
34 #include "../common/common.h"
35 #include "../ex/script.h"
36 #include "cl.h"
37 
38 static input_t	cl_read __P((SCR *,
39     u_int32_t, CHAR_T *, size_t, int *, struct timeval *));
40 static int	cl_resize __P((SCR *, size_t, size_t));
41 
42 /*
43  * cl_event --
44  *	Return a single event.
45  *
46  * PUBLIC: int cl_event __P((SCR *, EVENT *, u_int32_t, int));
47  */
48 int
49 cl_event(sp, evp, flags, ms)
50 	SCR *sp;
51 	EVENT *evp;
52 	u_int32_t flags;
53 	int ms;
54 {
55 	struct timeval t, *tp;
56 	CL_PRIVATE *clp;
57 	size_t lines, columns;
58 	int changed, nr;
59 
60 	/*
61 	 * Queue signal based events.  We never clear SIGHUP or SIGTERM events,
62 	 * so that we just keep returning them until the editor dies.
63 	 */
64 	clp = CLP(sp);
65 retest:	if (LF_ISSET(EC_INTERRUPT) || F_ISSET(clp, CL_SIGINT)) {
66 		if (F_ISSET(clp, CL_SIGINT)) {
67 			F_CLR(clp, CL_SIGINT);
68 			evp->e_event = E_INTERRUPT;
69 		} else
70 			evp->e_event = E_TIMEOUT;
71 		return (0);
72 	}
73 	if (F_ISSET(clp, CL_SIGHUP | CL_SIGTERM | CL_SIGWINCH)) {
74 		if (F_ISSET(clp, CL_SIGHUP)) {
75 			evp->e_event = E_SIGHUP;
76 			return (0);
77 		}
78 		if (F_ISSET(clp, CL_SIGTERM)) {
79 			evp->e_event = E_SIGTERM;
80 			return (0);
81 		}
82 		if (F_ISSET(clp, CL_SIGWINCH)) {
83 			F_CLR(clp, CL_SIGWINCH);
84 			if (cl_ssize(sp, 1, &lines, &columns, &changed))
85 				return (1);
86 			if (changed) {
87 				(void)cl_resize(sp, lines, columns);
88 				evp->e_event = E_WRESIZE;
89 				return (0);
90 			}
91 			/* No real change, ignore the signal. */
92 		}
93 	}
94 
95 	/* Set timer. */
96 	if (ms == 0)
97 		tp = NULL;
98 	else {
99 		t.tv_sec = ms / 1000;
100 		t.tv_usec = (ms % 1000) * 1000;
101 		tp = &t;
102 	}
103 
104 	/* Read input characters. */
105 	switch (cl_read(sp, LF_ISSET(EC_QUOTED | EC_RAW),
106 	    clp->ibuf, sizeof(clp->ibuf), &nr, tp)) {
107 	case INP_OK:
108 		evp->e_csp = clp->ibuf;
109 		evp->e_len = nr;
110 		evp->e_event = E_STRING;
111 		break;
112 	case INP_EOF:
113 		evp->e_event = E_EOF;
114 		break;
115 	case INP_ERR:
116 		evp->e_event = E_ERR;
117 		break;
118 	case INP_INTR:
119 		goto retest;
120 	case INP_TIMEOUT:
121 		evp->e_event = E_TIMEOUT;
122 		break;
123 	default:
124 		abort();
125 	}
126 	return (0);
127 }
128 
129 /*
130  * cl_read --
131  *	Read characters from the input.
132  */
133 static input_t
134 cl_read(sp, flags, bp, blen, nrp, tp)
135 	SCR *sp;
136 	u_int32_t flags;
137 	CHAR_T *bp;
138 	size_t blen;
139 	int *nrp;
140 	struct timeval *tp;
141 {
142 	struct termios term1, term2;
143 	struct timeval poll;
144 	CL_PRIVATE *clp;
145 	GS *gp;
146 	SCR *tsp;
147 	fd_set rdfd;
148 	input_t rval;
149 	int maxfd, nr, term_reset;
150 
151 	gp = sp->gp;
152 	clp = CLP(sp);
153 	term_reset = 0;
154 
155 	/*
156 	 * 1: A read from a file or a pipe.  In this case, the reads
157 	 *    never timeout regardless.  This means that we can hang
158 	 *    when trying to complete a map, but we're going to hang
159 	 *    on the next read anyway.
160 	 */
161 	if (!F_ISSET(clp, CL_STDIN_TTY)) {
162 		switch (nr = read(STDIN_FILENO, bp, blen)) {
163 		case 0:
164 			return (INP_EOF);
165 		case -1:
166 			goto err;
167 		default:
168 			*nrp = nr;
169 			return (INP_OK);
170 		}
171 		/* NOTREACHED */
172 	}
173 
174 	/*
175 	 * 2: A read with an associated timeout, e.g., trying to complete
176 	 *    a map sequence.  If input exists, we fall into #3.
177 	 */
178 	FD_ZERO(&rdfd);
179 	poll.tv_sec = 0;
180 	poll.tv_usec = 0;
181 	if (tp != NULL) {
182 		FD_SET(STDIN_FILENO, &rdfd);
183 		switch (select(STDIN_FILENO + 1,
184 		    &rdfd, NULL, NULL, tp == NULL ? &poll : tp)) {
185 		case 0:
186 			return (INP_TIMEOUT);
187 		case -1:
188 			goto err;
189 		default:
190 			break;
191 		}
192 	}
193 
194 	/*
195 	 * The user can enter a key in the editor to quote a character.  If we
196 	 * get here and the next key is supposed to be quoted, do what we can.
197 	 * Reset the tty so that the user can enter a ^C, ^Q, ^S.  There's an
198 	 * obvious race here, when the key has already been entered, but there's
199 	 * nothing that we can do to fix that problem.
200 	 *
201 	 * The editor can ask for the next literal character even thought it's
202 	 * generally running in line-at-a-time mode.  Do what we can.
203 	 */
204 	if (LF_ISSET(EC_QUOTED | EC_RAW) && !tcgetattr(STDIN_FILENO, &term1)) {
205 		term_reset = 1;
206 		if (LF_ISSET(EC_QUOTED)) {
207 			term2 = term1;
208 			term2.c_lflag &= ~ISIG;
209 			term2.c_iflag &= ~(IXON | IXOFF);
210 			(void)tcsetattr(STDIN_FILENO,
211 			    TCSASOFT | TCSADRAIN, &term2);
212 		} else
213 			(void)tcsetattr(STDIN_FILENO,
214 			    TCSASOFT | TCSADRAIN, &clp->vi_enter);
215 	}
216 
217 	/*
218 	 * 3: Wait for input.
219 	 *
220 	 * Select on the command input and scripting window file descriptors.
221 	 * It's ugly that we wait on scripting file descriptors here, but it's
222 	 * the only way to keep from locking out scripting windows.
223 	 */
224 	if (F_ISSET(gp, G_SCRWIN)) {
225 loop:		FD_ZERO(&rdfd);
226 		FD_SET(STDIN_FILENO, &rdfd);
227 		maxfd = STDIN_FILENO;
228 		for (tsp = gp->dq.cqh_first;
229 		    tsp != (void *)&gp->dq; tsp = tsp->q.cqe_next)
230 			if (F_ISSET(sp, SC_SCRIPT)) {
231 				FD_SET(sp->script->sh_master, &rdfd);
232 				if (sp->script->sh_master > maxfd)
233 					maxfd = sp->script->sh_master;
234 			}
235 		switch (select(maxfd + 1, &rdfd, NULL, NULL, NULL)) {
236 		case 0:
237 			abort();
238 		case -1:
239 			goto err;
240 		default:
241 			break;
242 		}
243 		if (!FD_ISSET(STDIN_FILENO, &rdfd)) {
244 			if (sscr_input(sp))
245 				return (INP_ERR);
246 			goto loop;
247 		}
248 	}
249 
250 	/*
251 	 * 4: Read the input.
252 	 *
253 	 * !!!
254 	 * What's going on here is some scary stuff.  Ex runs the terminal in
255 	 * canonical mode.  So, the <newline> character terminating a line of
256 	 * input is returned in the buffer, but a trailing <EOF> character is
257 	 * not similarly included.  As ex uses 0<EOF> and ^<EOF> as autoindent
258 	 * commands, it has to see the trailing <EOF> characters to determine
259 	 * the difference between the user entering "0ab" and "0<EOF>ab".  We
260 	 * leave an extra slot in the buffer, so that we can add a trailing
261 	 * <EOF> character if the buffer isn't terminated by a <newline>.  We
262 	 * lose if the buffer is too small for the line and exactly N characters
263 	 * are entered followed by an <EOF> character.
264 	 */
265 #define	ONE_FOR_EOF	1
266 	switch (nr = read(STDIN_FILENO, bp, blen - ONE_FOR_EOF)) {
267 	case  0:				/* EOF. */
268 		/*
269 		 * ^D in canonical mode returns a read of 0, i.e. EOF.  EOF is
270 		 * a valid command, but we don't want to loop forever because
271 		 * the terminal driver is returning EOF because the user has
272 		 * disconnected. The editor will almost certainly try to write
273 		 * something before this fires, which should kill us, but You
274 		 * Never Know.
275 		 */
276 		if (++clp->eof_count < 50) {
277 			bp[0] = clp->orig.c_cc[VEOF];
278 			*nrp = 1;
279 			rval = INP_OK;
280 
281 		} else
282 			rval = INP_EOF;
283 		break;
284 	case -1:				/* Error or interrupt. */
285 err:		if (errno == EINTR)
286 			rval = INP_INTR;
287 		else {
288 			rval = INP_ERR;
289 			msgq(sp, M_SYSERR, "input");
290 		}
291 		break;
292 	default:				/* Input characters. */
293 		if (F_ISSET(sp, SC_EX) && bp[nr - 1] != '\n')
294 			bp[nr++] = clp->orig.c_cc[VEOF];
295 		*nrp = nr;
296 		clp->eof_count = 0;
297 		rval = INP_OK;
298 		break;
299 	}
300 
301 	/* Restore the terminal state if it was modified. */
302 	if (term_reset)
303 		(void)tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &term1);
304 	return (rval);
305 }
306 
307 /*
308  * cl_resize --
309  *	Reset the options for a resize event.
310  */
311 static int
312 cl_resize(sp, lines, columns)
313 	SCR *sp;
314 	size_t lines, columns;
315 {
316 	ARGS *argv[2], a, b;
317 	char b1[1024];
318 
319 	a.bp = b1;
320 	b.bp = NULL;
321 	a.len = b.len = 0;
322 	argv[0] = &a;
323 	argv[1] = &b;
324 
325 	(void)snprintf(b1, sizeof(b1), "lines=%lu", (u_long)lines);
326 	a.len = strlen(b1);
327 	if (opts_set(sp, argv, NULL))
328 		return (1);
329 	(void)snprintf(b1, sizeof(b1), "columns=%lu", (u_long)columns);
330 	a.len = strlen(b1);
331 	if (opts_set(sp, argv, NULL))
332 		return (1);
333 	return (0);
334 }
335