xref: /freebsd/contrib/nvi/cl/cl_read.c (revision a18eacbefdfa1085ca3db829e86ece78cd416493)
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[] = "$Id: cl_read.c,v 10.30 2012/07/12 18:28:58 zy Exp $";
14 #endif /* not lint */
15 
16 #include <sys/types.h>
17 #include <sys/queue.h>
18 #include <sys/select.h>
19 
20 #include <bitstring.h>
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <signal.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <termios.h>
28 #include <unistd.h>
29 
30 #include "../common/common.h"
31 #include "../ex/script.h"
32 #include "cl.h"
33 
34 /* Pollution by Solaris curses. */
35 #undef columns
36 #undef lines
37 
38 static input_t	cl_read __P((SCR *,
39     u_int32_t, char *, 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(SCR *sp, EVENT *evp, u_int32_t flags, int ms)
50 {
51 	struct timeval t, *tp;
52 	CL_PRIVATE *clp;
53 	size_t lines, columns;
54 	int changed, nr = 0;
55 	CHAR_T *wp;
56 	size_t wlen;
57 	int rc;
58 
59 	/*
60 	 * Queue signal based events.  We never clear SIGHUP or SIGTERM events,
61 	 * so that we just keep returning them until the editor dies.
62 	 */
63 	clp = CLP(sp);
64 retest:	if (LF_ISSET(EC_INTERRUPT) || F_ISSET(clp, CL_SIGINT)) {
65 		if (F_ISSET(clp, CL_SIGINT)) {
66 			F_CLR(clp, CL_SIGINT);
67 			evp->e_event = E_INTERRUPT;
68 		} else
69 			evp->e_event = E_TIMEOUT;
70 		return (0);
71 	}
72 	if (F_ISSET(clp, CL_SIGHUP | CL_SIGTERM | CL_SIGWINCH)) {
73 		if (F_ISSET(clp, CL_SIGHUP)) {
74 			evp->e_event = E_SIGHUP;
75 			return (0);
76 		}
77 		if (F_ISSET(clp, CL_SIGTERM)) {
78 			evp->e_event = E_SIGTERM;
79 			return (0);
80 		}
81 		if (F_ISSET(clp, CL_SIGWINCH)) {
82 			F_CLR(clp, CL_SIGWINCH);
83 			if (cl_ssize(sp, 1, &lines, &columns, &changed))
84 				return (1);
85 			if (changed) {
86 				(void)cl_resize(sp, lines, columns);
87 				evp->e_event = E_WRESIZE;
88 				return (0);
89 			}
90 			/* No real change, ignore the signal. */
91 		}
92 	}
93 
94 	/* Set timer. */
95 	if (ms == 0)
96 		tp = NULL;
97 	else {
98 		t.tv_sec = ms / 1000;
99 		t.tv_usec = (ms % 1000) * 1000;
100 		tp = &t;
101 	}
102 
103 	/* Read input characters. */
104 read:
105 	switch (cl_read(sp, LF_ISSET(EC_QUOTED | EC_RAW),
106 	    clp->ibuf + clp->skip, SIZE(clp->ibuf) - clp->skip, &nr, tp)) {
107 	case INP_OK:
108 		rc = INPUT2INT5(sp, clp->cw, clp->ibuf, nr + clp->skip,
109 				wp, wlen);
110 		evp->e_csp = wp;
111 		evp->e_len = wlen;
112 		evp->e_event = E_STRING;
113 		if (rc < 0) {
114 		    int n = -rc;
115 		    memmove(clp->ibuf, clp->ibuf + nr + clp->skip - n, n);
116 		    clp->skip = n;
117 		    if (wlen == 0)
118 			goto read;
119 		} else if (rc == 0)
120 		    clp->skip = 0;
121 		else
122 		    msgq(sp, M_ERR, "323|Invalid input. Truncated.");
123 		break;
124 	case INP_EOF:
125 		evp->e_event = E_EOF;
126 		break;
127 	case INP_ERR:
128 		evp->e_event = E_ERR;
129 		break;
130 	case INP_INTR:
131 		goto retest;
132 	case INP_TIMEOUT:
133 		evp->e_event = E_TIMEOUT;
134 		break;
135 	default:
136 		abort();
137 	}
138 	return (0);
139 }
140 
141 /*
142  * cl_read --
143  *	Read characters from the input.
144  */
145 static input_t
146 cl_read(SCR *sp, u_int32_t flags, char *bp, size_t blen, int *nrp, struct timeval *tp)
147 {
148 	struct termios term1, term2;
149 	CL_PRIVATE *clp;
150 	GS *gp;
151 	fd_set rdfd;
152 	input_t rval;
153 	int maxfd, nr, term_reset;
154 
155 	gp = sp->gp;
156 	clp = CLP(sp);
157 	term_reset = 0;
158 
159 	/*
160 	 * 1: A read from a file or a pipe.  In this case, the reads
161 	 *    never timeout regardless.  This means that we can hang
162 	 *    when trying to complete a map, but we're going to hang
163 	 *    on the next read anyway.
164 	 */
165 	if (!F_ISSET(clp, CL_STDIN_TTY)) {
166 		switch (nr = read(STDIN_FILENO, bp, blen)) {
167 		case 0:
168 			return (INP_EOF);
169 		case -1:
170 			goto err;
171 		default:
172 			*nrp = nr;
173 			return (INP_OK);
174 		}
175 		/* NOTREACHED */
176 	}
177 
178 	/*
179 	 * 2: A read with an associated timeout, e.g., trying to complete
180 	 *    a map sequence.  If input exists, we fall into #3.
181 	 */
182 	if (tp != NULL) {
183 		FD_ZERO(&rdfd);
184 		FD_SET(STDIN_FILENO, &rdfd);
185 		switch (select(STDIN_FILENO + 1, &rdfd, NULL, NULL, tp)) {
186 		case 0:
187 			return (INP_TIMEOUT);
188 		case -1:
189 			goto err;
190 		default:
191 			break;
192 		}
193 	}
194 
195 	/*
196 	 * The user can enter a key in the editor to quote a character.  If we
197 	 * get here and the next key is supposed to be quoted, do what we can.
198 	 * Reset the tty so that the user can enter a ^C, ^Q, ^S.  There's an
199 	 * obvious race here, when the key has already been entered, but there's
200 	 * nothing that we can do to fix that problem.
201 	 *
202 	 * The editor can ask for the next literal character even thought it's
203 	 * generally running in line-at-a-time mode.  Do what we can.
204 	 */
205 	if (LF_ISSET(EC_QUOTED | EC_RAW) && !tcgetattr(STDIN_FILENO, &term1)) {
206 		term_reset = 1;
207 		if (LF_ISSET(EC_QUOTED)) {
208 			term2 = term1;
209 			term2.c_lflag &= ~ISIG;
210 			term2.c_iflag &= ~(IXON | IXOFF);
211 			(void)tcsetattr(STDIN_FILENO,
212 			    TCSASOFT | TCSADRAIN, &term2);
213 		} else
214 			(void)tcsetattr(STDIN_FILENO,
215 			    TCSASOFT | TCSADRAIN, &clp->vi_enter);
216 	}
217 
218 	/*
219 	 * 3: Wait for input.
220 	 *
221 	 * Select on the command input and scripting window file descriptors.
222 	 * It's ugly that we wait on scripting file descriptors here, but it's
223 	 * the only way to keep from locking out scripting windows.
224 	 */
225 	if (F_ISSET(gp, G_SCRWIN)) {
226 loop:		FD_ZERO(&rdfd);
227 		FD_SET(STDIN_FILENO, &rdfd);
228 		maxfd = STDIN_FILENO;
229 		if (F_ISSET(sp, SC_SCRIPT)) {
230 			FD_SET(sp->script->sh_master, &rdfd);
231 			if (sp->script->sh_master > maxfd)
232 				maxfd = sp->script->sh_master;
233 		}
234 		switch (select(maxfd + 1, &rdfd, NULL, NULL, NULL)) {
235 		case 0:
236 			abort();
237 		case -1:
238 			goto err;
239 		default:
240 			break;
241 		}
242 		if (!FD_ISSET(STDIN_FILENO, &rdfd)) {
243 			if (sscr_input(sp))
244 				return (INP_ERR);
245 			goto loop;
246 		}
247 	}
248 
249 	/*
250 	 * 4: Read the input.
251 	 *
252 	 * !!!
253 	 * What's going on here is some scary stuff.  Ex runs the terminal in
254 	 * canonical mode.  So, the <newline> character terminating a line of
255 	 * input is returned in the buffer, but a trailing <EOF> character is
256 	 * not similarly included.  As ex uses 0<EOF> and ^<EOF> as autoindent
257 	 * commands, it has to see the trailing <EOF> characters to determine
258 	 * the difference between the user entering "0ab" and "0<EOF>ab".  We
259 	 * leave an extra slot in the buffer, so that we can add a trailing
260 	 * <EOF> character if the buffer isn't terminated by a <newline>.  We
261 	 * lose if the buffer is too small for the line and exactly N characters
262 	 * are entered followed by an <EOF> character.
263 	 */
264 #define	ONE_FOR_EOF	1
265 	switch (nr = read(STDIN_FILENO, bp, blen - ONE_FOR_EOF)) {
266 	case  0:				/* EOF. */
267 		/*
268 		 * ^D in canonical mode returns a read of 0, i.e. EOF.  EOF is
269 		 * a valid command, but we don't want to loop forever because
270 		 * the terminal driver is returning EOF because the user has
271 		 * disconnected. The editor will almost certainly try to write
272 		 * something before this fires, which should kill us, but You
273 		 * Never Know.
274 		 */
275 		if (++clp->eof_count < 50) {
276 			bp[0] = clp->orig.c_cc[VEOF];
277 			*nrp = 1;
278 			rval = INP_OK;
279 
280 		} else
281 			rval = INP_EOF;
282 		break;
283 	case -1:				/* Error or interrupt. */
284 err:		if (errno == EINTR)
285 			rval = INP_INTR;
286 		else {
287 			rval = INP_ERR;
288 			msgq(sp, M_SYSERR, "input");
289 		}
290 		break;
291 	default:				/* Input characters. */
292 		if (F_ISSET(sp, SC_EX) && bp[nr - 1] != '\n')
293 			bp[nr++] = clp->orig.c_cc[VEOF];
294 		*nrp = nr;
295 		clp->eof_count = 0;
296 		rval = INP_OK;
297 		break;
298 	}
299 
300 	/* Restore the terminal state if it was modified. */
301 	if (term_reset)
302 		(void)tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &term1);
303 	return (rval);
304 }
305 
306 /*
307  * cl_resize --
308  *	Reset the options for a resize event.
309  */
310 static int
311 cl_resize(SCR *sp, size_t lines, size_t columns)
312 {
313 	ARGS *argv[2], a, b;
314 	CHAR_T b1[1024];
315 
316 	a.bp = b1;
317 	b.bp = NULL;
318 	a.len = b.len = 0;
319 	argv[0] = &a;
320 	argv[1] = &b;
321 
322 	a.len = SPRINTF(b1, sizeof(b1), L("lines=%lu"), (u_long)lines);
323 	if (opts_set(sp, argv, NULL))
324 		return (1);
325 	a.len = SPRINTF(b1, sizeof(b1), L("columns=%lu"), (u_long)columns);
326 	if (opts_set(sp, argv, NULL))
327 		return (1);
328 	return (0);
329 }
330