xref: /freebsd/contrib/nvi/cl/cl_read.c (revision ae41709ab46305df80f7f35bb478a3c8ebf22ebb)
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 #include <sys/types.h>
13 #include <sys/queue.h>
14 #include <sys/select.h>
15 
16 #include <bitstring.h>
17 #include <errno.h>
18 #include <fcntl.h>
19 #include <signal.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <sys/ioctl.h>
24 #include <termios.h>
25 #include <unistd.h>
26 
27 #include "../common/common.h"
28 #include "../ex/script.h"
29 #include "cl.h"
30 
31 /* Pollution by Solaris curses. */
32 #undef columns
33 #undef lines
34 
35 static input_t	cl_read(SCR *,
36     u_int32_t, char *, size_t, int *, struct timeval *);
37 static int	cl_resize(SCR *, size_t, size_t);
38 
39 /*
40  * cl_event --
41  *	Return a single event.
42  *
43  * PUBLIC: int cl_event(SCR *, EVENT *, u_int32_t, int);
44  */
45 int
46 cl_event(SCR *sp, EVENT *evp, u_int32_t flags, int ms)
47 {
48 	struct timeval t, *tp;
49 	CL_PRIVATE *clp;
50 	size_t lines, columns;
51 	int changed, nr = 0;
52 	CHAR_T *wp;
53 	size_t wlen;
54 	int rc;
55 
56 	/*
57 	 * Queue signal based events.  We never clear SIGHUP or SIGTERM events,
58 	 * so that we just keep returning them until the editor dies.
59 	 */
60 	clp = CLP(sp);
61 retest:	if (LF_ISSET(EC_INTERRUPT) || F_ISSET(clp, CL_SIGINT)) {
62 		if (F_ISSET(clp, CL_SIGINT)) {
63 			F_CLR(clp, CL_SIGINT);
64 			evp->e_event = E_INTERRUPT;
65 		} else
66 			evp->e_event = E_TIMEOUT;
67 		return (0);
68 	}
69 	if (F_ISSET(clp, CL_SIGHUP | CL_SIGTERM | CL_SIGWINCH)) {
70 		if (F_ISSET(clp, CL_SIGHUP)) {
71 			evp->e_event = E_SIGHUP;
72 			return (0);
73 		}
74 		if (F_ISSET(clp, CL_SIGTERM)) {
75 			evp->e_event = E_SIGTERM;
76 			return (0);
77 		}
78 		if (F_ISSET(clp, CL_SIGWINCH)) {
79 			F_CLR(clp, CL_SIGWINCH);
80 			if (cl_ssize(sp, 1, &lines, &columns, &changed))
81 				return (1);
82 			if (changed) {
83 				(void)cl_resize(sp, lines, columns);
84 				evp->e_event = E_WRESIZE;
85 				return (0);
86 			}
87 			/* No real change, ignore the signal. */
88 		}
89 	}
90 
91 	/* Set timer. */
92 	if (ms == 0)
93 		tp = NULL;
94 	else {
95 		t.tv_sec = ms / 1000;
96 		t.tv_usec = (ms % 1000) * 1000;
97 		tp = &t;
98 	}
99 
100 	/* Read input characters. */
101 read:
102 	switch (cl_read(sp, LF_ISSET(EC_QUOTED | EC_RAW),
103 	    clp->ibuf + clp->skip, SIZE(clp->ibuf) - clp->skip, &nr, tp)) {
104 	case INP_OK:
105 		rc = INPUT2INT5(sp, clp->cw, clp->ibuf, nr + clp->skip,
106 				wp, wlen);
107 		evp->e_csp = wp;
108 		evp->e_len = wlen;
109 		evp->e_event = E_STRING;
110 		if (rc < 0) {
111 		    int n = -rc;
112 		    memmove(clp->ibuf, clp->ibuf + nr + clp->skip - n, n);
113 		    clp->skip = n;
114 		    if (wlen == 0)
115 			goto read;
116 		} else if (rc == 0)
117 		    clp->skip = 0;
118 		else
119 		    msgq(sp, M_ERR, "323|Invalid input. Truncated.");
120 		break;
121 	case INP_EOF:
122 		evp->e_event = E_EOF;
123 		break;
124 	case INP_ERR:
125 		evp->e_event = E_ERR;
126 		break;
127 	case INP_INTR:
128 		goto retest;
129 	case INP_TIMEOUT:
130 		evp->e_event = E_TIMEOUT;
131 		break;
132 	default:
133 		abort();
134 	}
135 	return (0);
136 }
137 
138 /*
139  * cl_read --
140  *	Read characters from the input.
141  */
142 static input_t
143 cl_read(SCR *sp, u_int32_t flags, char *bp, size_t blen, int *nrp,
144     struct timeval *tp)
145 {
146 	struct termios term1, term2;
147 	CL_PRIVATE *clp;
148 	GS *gp;
149 	fd_set rdfd;
150 	input_t rval;
151 	int maxfd, nr, term_reset;
152 
153 	gp = sp->gp;
154 	clp = CLP(sp);
155 	term_reset = 0;
156 
157 	/*
158 	 * 1: A read from a file or a pipe.  In this case, the reads
159 	 *    never timeout regardless.  This means that we can hang
160 	 *    when trying to complete a map, but we're going to hang
161 	 *    on the next read anyway.
162 	 */
163 	if (!F_ISSET(clp, CL_STDIN_TTY)) {
164 		switch (nr = read(STDIN_FILENO, bp, blen)) {
165 		case 0:
166 			return (INP_EOF);
167 		case -1:
168 			goto err;
169 		default:
170 			*nrp = nr;
171 			return (INP_OK);
172 		}
173 		/* NOTREACHED */
174 	}
175 
176 	/*
177 	 * 2: A read with an associated timeout, e.g., trying to complete
178 	 *    a map sequence.  If input exists, we fall into #3.
179 	 */
180 	if (tp != NULL) {
181 		FD_ZERO(&rdfd);
182 		FD_SET(STDIN_FILENO, &rdfd);
183 		switch (select(STDIN_FILENO + 1, &rdfd, NULL, NULL, tp)) {
184 		case 0:
185 			return (INP_TIMEOUT);
186 		case -1:
187 			goto err;
188 		default:
189 			break;
190 		}
191 	}
192 
193 	/*
194 	 * The user can enter a key in the editor to quote a character.  If we
195 	 * get here and the next key is supposed to be quoted, do what we can.
196 	 * Reset the tty so that the user can enter a ^C, ^Q, ^S.  There's an
197 	 * obvious race here, when the key has already been entered, but there's
198 	 * nothing that we can do to fix that problem.
199 	 *
200 	 * The editor can ask for the next literal character even thought it's
201 	 * generally running in line-at-a-time mode.  Do what we can.
202 	 */
203 	if (LF_ISSET(EC_QUOTED | EC_RAW) && !tcgetattr(STDIN_FILENO, &term1)) {
204 		term_reset = 1;
205 		if (LF_ISSET(EC_QUOTED)) {
206 			term2 = term1;
207 			term2.c_lflag &= ~ISIG;
208 			term2.c_iflag &= ~(IXON | IXOFF);
209 			(void)tcsetattr(STDIN_FILENO,
210 			    TCSASOFT | TCSADRAIN, &term2);
211 		} else
212 			(void)tcsetattr(STDIN_FILENO,
213 			    TCSASOFT | TCSADRAIN, &clp->vi_enter);
214 	}
215 
216 	/*
217 	 * 3: Wait for input.
218 	 *
219 	 * Select on the command input and scripting window file descriptors.
220 	 * It's ugly that we wait on scripting file descriptors here, but it's
221 	 * the only way to keep from locking out scripting windows.
222 	 */
223 	if (F_ISSET(gp, G_SCRWIN)) {
224 loop:		FD_ZERO(&rdfd);
225 		FD_SET(STDIN_FILENO, &rdfd);
226 		maxfd = STDIN_FILENO;
227 		if (F_ISSET(sp, SC_SCRIPT)) {
228 			FD_SET(sp->script->sh_master, &rdfd);
229 			if (sp->script->sh_master > maxfd)
230 				maxfd = sp->script->sh_master;
231 		}
232 		switch (select(maxfd + 1, &rdfd, NULL, NULL, NULL)) {
233 		case 0:
234 			abort();
235 		case -1:
236 			goto err;
237 		default:
238 			break;
239 		}
240 		if (!FD_ISSET(STDIN_FILENO, &rdfd)) {
241 			if (sscr_input(sp))
242 				return (INP_ERR);
243 			goto loop;
244 		}
245 	}
246 
247 	/*
248 	 * 4: Read the input.
249 	 *
250 	 * !!!
251 	 * What's going on here is some scary stuff.  Ex runs the terminal in
252 	 * canonical mode.  So, the <newline> character terminating a line of
253 	 * input is returned in the buffer, but a trailing <EOF> character is
254 	 * not similarly included.  As ex uses 0<EOF> and ^<EOF> as autoindent
255 	 * commands, it has to see the trailing <EOF> characters to determine
256 	 * the difference between the user entering "0ab" and "0<EOF>ab".  We
257 	 * leave an extra slot in the buffer, so that we can add a trailing
258 	 * <EOF> character if the buffer isn't terminated by a <newline>.  We
259 	 * lose if the buffer is too small for the line and exactly N characters
260 	 * are entered followed by an <EOF> character.
261 	 */
262 #define	ONE_FOR_EOF	1
263 	switch (nr = read(STDIN_FILENO, bp, blen - ONE_FOR_EOF)) {
264 	case  0:				/* EOF. */
265 		/*
266 		 * ^D in canonical mode returns a read of 0, i.e. EOF.  EOF is
267 		 * a valid command, but we don't want to loop forever because
268 		 * the terminal driver is returning EOF because the user has
269 		 * disconnected. The editor will almost certainly try to write
270 		 * something before this fires, which should kill us, but You
271 		 * Never Know.
272 		 */
273 		if (++clp->eof_count < 50) {
274 			bp[0] = clp->orig.c_cc[VEOF];
275 			*nrp = 1;
276 			rval = INP_OK;
277 
278 		} else
279 			rval = INP_EOF;
280 		break;
281 	case -1:				/* Error or interrupt. */
282 err:		if (errno == EINTR)
283 			rval = INP_INTR;
284 		else {
285 			rval = INP_ERR;
286 			msgq(sp, M_SYSERR, "input");
287 		}
288 		break;
289 	default:				/* Input characters. */
290 		if (F_ISSET(sp, SC_EX) && bp[nr - 1] != '\n')
291 			bp[nr++] = clp->orig.c_cc[VEOF];
292 		*nrp = nr;
293 		clp->eof_count = 0;
294 		rval = INP_OK;
295 		break;
296 	}
297 
298 	/* Restore the terminal state if it was modified. */
299 	if (term_reset)
300 		(void)tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &term1);
301 	return (rval);
302 }
303 
304 /*
305  * cl_resize --
306  *	Reset the options for a resize event.
307  */
308 static int
309 cl_resize(SCR *sp, size_t lines, size_t columns)
310 {
311 	ARGS *argv[2], a, b;
312 	CHAR_T b1[1024];
313 
314 	a.bp = b1;
315 	b.bp = NULL;
316 	a.len = b.len = 0;
317 	argv[0] = &a;
318 	argv[1] = &b;
319 
320 	a.len = SPRINTF(b1, sizeof(b1), L("lines=%lu"), (u_long)lines);
321 	if (opts_set(sp, argv, NULL))
322 		return (1);
323 	a.len = SPRINTF(b1, sizeof(b1), L("columns=%lu"), (u_long)columns);
324 	if (opts_set(sp, argv, NULL))
325 		return (1);
326 	return (0);
327 }
328