xref: /original-bsd/usr.bin/ex/ex.c (revision 552e81d8)
1 /* Copyright (c) 1980 Regents of the University of California */
2 static char *sccsid = "@(#)ex.c	5.3 09/13/80";
3 #include "ex.h"
4 #include "ex_argv.h"
5 #include "ex_temp.h"
6 #include "ex_tty.h"
7 
8 #ifdef TRACE
9 char	tttrace[]	= { '/','d','e','v','/','t','t','y','x','x',0 };
10 #endif
11 
12 /*
13  * The code for ex is divided as follows:
14  *
15  * ex.c			Entry point and routines handling interrupt, hangup
16  *			signals; initialization code.
17  *
18  * ex_addr.c		Address parsing routines for command mode decoding.
19  *			Routines to set and check address ranges on commands.
20  *
21  * ex_cmds.c		Command mode command decoding.
22  *
23  * ex_cmds2.c		Subroutines for command decoding and processing of
24  *			file names in the argument list.  Routines to print
25  *			messages and reset state when errors occur.
26  *
27  * ex_cmdsub.c		Subroutines which implement command mode functions
28  *			such as append, delete, join.
29  *
30  * ex_data.c		Initialization of options.
31  *
32  * ex_get.c		Command mode input routines.
33  *
34  * ex_io.c		General input/output processing: file i/o, unix
35  *			escapes, filtering, source commands, preserving
36  *			and recovering.
37  *
38  * ex_put.c		Terminal driving and optimizing routines for low-level
39  *			output (cursor-positioning); output line formatting
40  *			routines.
41  *
42  * ex_re.c		Global commands, substitute, regular expression
43  *			compilation and execution.
44  *
45  * ex_set.c		The set command.
46  *
47  * ex_subr.c		Loads of miscellaneous subroutines.
48  *
49  * ex_temp.c		Editor buffer routines for main buffer and also
50  *			for named buffers (Q registers if you will.)
51  *
52  * ex_tty.c		Terminal dependent initializations from termcap
53  *			data base, grabbing of tty modes (at beginning
54  *			and after escapes).
55  *
56  * ex_unix.c		Routines for the ! command and its variations.
57  *
58  * ex_v*.c		Visual/open mode routines... see ex_v.c for a
59  *			guide to the overall organization.
60  */
61 
62 /*
63  * Main procedure.  Process arguments and then
64  * transfer control to the main command processing loop
65  * in the routine commands.  We are entered as either "ex", "edit", "vi"
66  * or "view" and the distinction is made here.  Actually, we are "vi" if
67  * there is a 'v' in our name, "view" is there is a 'w', and "edit" if
68  * there is a 'd' in our name.  For edit we just diddle options;
69  * for vi we actually force an early visual command.
70  */
71 main(ac, av)
72 	register int ac;
73 	register char *av[];
74 {
75 #ifndef VMUNIX
76 	char *erpath = EXSTRINGS;
77 #endif
78 	register char *cp;
79 	register int c;
80 	bool recov = 0;
81 	bool ivis;
82 	bool itag = 0;
83 	bool fast = 0;
84 #ifdef TRACE
85 	register char *tracef;
86 #endif
87 
88 	/*
89 	 * Immediately grab the tty modes so that we wont
90 	 * get messed up if an interrupt comes in quickly.
91 	 */
92 	gTTY(1);
93 #ifndef USG3TTY
94 	normf = tty.sg_flags;
95 #else
96 	normf = tty;
97 #endif
98 	ppid = getpid();
99 	/*
100 	 * Defend against d's, v's, w's, and a's in directories of
101 	 * path leading to our true name.
102 	 */
103 	av[0] = tailpath(av[0]);
104 
105 	/*
106 	 * Figure out how we were invoked: ex, edit, vi, view.
107 	 */
108 	ivis = any('v', av[0]);	/* "vi" */
109 	if (any('w', av[0]))	/* "view" */
110 		value(READONLY) = 1;
111 	if (any('d', av[0])) {	/* "edit" */
112 		value(OPEN) = 0;
113 		value(REPORT) = 1;
114 		value(MAGIC) = 0;
115 	}
116 
117 #ifndef VMUNIX
118 	/*
119 	 * For debugging take files out of . if name is a.out.
120 	 */
121 	if (av[0][0] == 'a')
122 		erpath = tailpath(erpath);
123 #endif
124 	/*
125 	 * Open the error message file.
126 	 */
127 	draino();
128 #ifndef VMUNIX
129 	erfile = open(erpath+4, 0);
130 	if (erfile < 0) {
131 		erfile = open(erpath, 0);
132 	}
133 #endif
134 	pstop();
135 
136 	/*
137 	 * Initialize interrupt handling.
138 	 */
139 	oldhup = signal(SIGHUP, SIG_IGN);
140 	if (oldhup == SIG_DFL)
141 		signal(SIGHUP, onhup);
142 	oldquit = signal(SIGQUIT, SIG_IGN);
143 	ruptible = signal(SIGINT, SIG_IGN) == SIG_DFL;
144 	if (signal(SIGTERM, SIG_IGN) == SIG_DFL)
145 		signal(SIGTERM, onhup);
146 #ifdef SIGTSTP
147 	if (signal(SIGTSTP, SIG_IGN) == SIG_DFL)
148 		signal(SIGTSTP, onsusp), dosusp++;
149 #endif
150 
151 	/*
152 	 * Initialize end of core pointers.
153 	 * Normally we avoid breaking back to fendcore after each
154 	 * file since this can be expensive (much core-core copying).
155 	 * If your system can scatter load processes you could do
156 	 * this as ed does, saving a little core, but it will probably
157 	 * not often make much difference.
158 	 */
159 	fendcore = (line *) sbrk(0);
160 	endcore = fendcore - 2;
161 
162 	/*
163 	 * Process flag arguments.
164 	 */
165 	ac--, av++;
166 	while (ac && av[0][0] == '-') {
167 		c = av[0][1];
168 		if (c == 0) {
169 			hush = 1;
170 			value(AUTOPRINT) = 0;
171 			fast++;
172 		} else switch (c) {
173 
174 		case 'R':
175 			value(READONLY) = 1;
176 			break;
177 
178 #ifdef TRACE
179 		case 'T':
180 			if (av[0][2] == 0)
181 				tracef = "trace";
182 			else {
183 				tracef = tttrace;
184 				tracef[8] = av[0][2];
185 				if (tracef[8])
186 					tracef[9] = av[0][3];
187 				else
188 					tracef[9] = 0;
189 			}
190 			trace = fopen(tracef, "w");
191 			if (trace == NULL)
192 				printf("Trace create error\n");
193 			setbuf(trace, tracbuf);
194 			break;
195 
196 #endif
197 
198 #ifdef LISPCODE
199 		case 'l':
200 			value(LISP) = 1;
201 			value(SHOWMATCH) = 1;
202 			break;
203 #endif
204 
205 		case 'r':
206 			recov++;
207 			break;
208 
209 		case 't':
210 			if (ac > 1 && av[1][0] != '-') {
211 				ac--, av++;
212 				itag = 1;
213 				/* BUG: should check for too long tag. */
214 				CP(lasttag, av[0]);
215 			}
216 			break;
217 
218 		case 'v':
219 			ivis = 1;
220 			break;
221 
222 		case 'w':
223 			defwind = 0;
224 			if (av[0][2] == 0) defwind = 3;
225 			else for (cp = &av[0][2]; isdigit(*cp); cp++)
226 				defwind = 10*defwind + *cp - '0';
227 			break;
228 
229 #ifdef CRYPT
230 		case 'x':
231 			/* -x: encrypted mode */
232 			xflag = 1;
233 			break;
234 #endif
235 
236 		default:
237 			smerror("Unknown option %s\n", av[0]);
238 			break;
239 		}
240 		ac--, av++;
241 	}
242 	if (ac && av[0][0] == '+') {
243 		firstpat = &av[0][1];
244 		ac--, av++;
245 	}
246 
247 #ifdef CRYPT
248 	if(xflag){
249 		key = getpass(KEYPROMPT);
250 		kflag = crinit(key, perm);
251 	}
252 #endif
253 
254 	/*
255 	 * If we are doing a recover and no filename
256 	 * was given, then execute an exrecover command with
257 	 * the -r option to type out the list of saved file names.
258 	 * Otherwise set the remembered file name to the first argument
259 	 * file name so the "recover" initial command will find it.
260 	 */
261 	if (recov) {
262 		if (ac == 0) {
263 			ppid = 0;
264 			setrupt();
265 			execl(EXRECOVER, "exrecover", "-r", 0);
266 			filioerr(EXRECOVER);
267 			exit(1);
268 		}
269 		CP(savedfile, *av++), ac--;
270 	}
271 
272 	/*
273 	 * Initialize the argument list.
274 	 */
275 	argv0 = av;
276 	argc0 = ac;
277 	args0 = av[0];
278 	erewind();
279 
280 	/*
281 	 * Initialize a temporary file (buffer) and
282 	 * set up terminal environment.  Read user startup commands.
283 	 */
284 	init();
285 	if (setexit() == 0) {
286 		setrupt();
287 		intty = isatty(0);
288 		value(PROMPT) = intty;
289 		if (cp = getenv("SHELL"))
290 			CP(shell, cp);
291 		if (fast || !intty)
292 			setterm("dumb");
293 		else {
294 			gettmode();
295 			if ((cp = getenv("TERM")) != 0 && *cp)
296 				setterm(cp);
297 		}
298 	}
299 	if (setexit() == 0 && !fast && intty)
300 		if ((globp = getenv("EXINIT")) && *globp)
301 			commands(1,1);
302 		else {
303 			globp = 0;
304 			if ((cp = getenv("HOME")) != 0 && *cp)
305 				source(strcat(strcpy(genbuf, cp), "/.exrc"), 1);
306 		}
307 
308 	/*
309 	 * Initial processing.  Handle tag, recover, and file argument
310 	 * implied next commands.  If going in as 'vi', then don't do
311 	 * anything, just set initev so we will do it later (from within
312 	 * visual).
313 	 */
314 	if (setexit() == 0) {
315 		if (recov)
316 			globp = "recover";
317 		else if (itag)
318 			globp = ivis ? "tag" : "tag|p";
319 		else if (argc)
320 			globp = "next";
321 		if (ivis)
322 			initev = globp;
323 		else if (globp) {
324 			inglobal = 1;
325 			commands(1, 1);
326 			inglobal = 0;
327 		}
328 	}
329 
330 	/*
331 	 * Vi command... go into visual.
332 	 * Strange... everything in vi usually happens
333 	 * before we ever "start".
334 	 */
335 	if (ivis) {
336 		/*
337 		 * Don't have to be upward compatible with stupidity
338 		 * of starting editing at line $.
339 		 */
340 		if (dol > zero)
341 			dot = one;
342 		globp = "visual";
343 		if (setexit() == 0)
344 			commands(1, 1);
345 	}
346 
347 	/*
348 	 * Clear out trash in state accumulated by startup,
349 	 * and then do the main command loop for a normal edit.
350 	 * If you quit out of a 'vi' command by doing Q or ^\,
351 	 * you also fall through to here.
352 	 */
353 	ungetchar(0);
354 	globp = 0;
355 	initev = 0;
356 	setlastchar('\n');
357 	setexit();
358 	commands(0, 0);
359 	cleanup(1);
360 	exit(0);
361 }
362 
363 /*
364  * Initialization, before editing a new file.
365  * Main thing here is to get a new buffer (in fileinit),
366  * rest is peripheral state resetting.
367  */
368 init()
369 {
370 	register int i;
371 
372 	fileinit();
373 	dot = zero = truedol = unddol = dol = fendcore;
374 	one = zero+1;
375 	undkind = UNDNONE;
376 	chng = 0;
377 	edited = 0;
378 #ifdef USG
379 	signal (SIGHUP, SIG_IGN);
380 #endif
381 #ifdef USG3TTY
382 #ifndef USG
383 	signal (SIGHUP, SIG_IGN);
384 #endif
385 #endif
386 	for (i = 0; i <= 'z'-'a'+1; i++)
387 		names[i] = 1;
388 	anymarks = 0;
389 #ifdef CRYPT
390         if(xflag) {
391                 xtflag = 1;
392                 makekey(key, tperm);
393         }
394 #endif
395 }
396 
397 /*
398  * When a hangup occurs our actions are similar to a preserve
399  * command.  If the buffer has not been [Modified], then we do
400  * nothing but remove the temporary files and exit.
401  * Otherwise, we sync the temp file and then attempt a preserve.
402  * If the preserve succeeds, we unlink our temp files.
403  * If the preserve fails, we leave the temp files as they are
404  * as they are a backup even without preservation if they
405  * are not removed.
406  */
407 onhup()
408 {
409 
410 	/*
411 	 * USG tty driver can send multiple HUP's!!
412 	 */
413 	signal(SIGINT, SIG_IGN);
414 	signal(SIGHUP, SIG_IGN);
415 	if (chng == 0) {
416 		cleanup(1);
417 		exit(0);
418 	}
419 	if (setexit() == 0) {
420 		if (preserve()) {
421 			cleanup(1);
422 			exit(0);
423 		}
424 	}
425 	exit(1);
426 }
427 
428 /*
429  * An interrupt occurred.  Drain any output which
430  * is still in the output buffering pipeline.
431  * Catch interrupts again.  Unless we are in visual
432  * reset the output state (out of -nl mode, e.g).
433  * Then like a normal error (with the \n before Interrupt
434  * suppressed in visual mode).
435  */
436 onintr()
437 {
438 
439 #ifndef CBREAK
440 	signal(SIGINT, onintr);
441 #else
442 	signal(SIGINT, inopen ? vintr : onintr);
443 #endif
444 	draino();
445 	if (!inopen) {
446 		pstop();
447 		setlastchar('\n');
448 #ifdef CBREAK
449 	}
450 #else
451 	} else
452 		vraw();
453 #endif
454 	error("\nInterrupt" + inopen);
455 }
456 
457 /*
458  * If we are interruptible, enable interrupts again.
459  * In some critical sections we turn interrupts off,
460  * but not very often.
461  */
462 setrupt()
463 {
464 
465 	if (ruptible) {
466 #ifndef CBREAK
467 		signal(SIGINT, onintr);
468 #else
469 		signal(SIGINT, inopen ? vintr : onintr);
470 #endif
471 #ifdef SIGTSTP
472 		if (dosusp)
473 			signal(SIGTSTP, onsusp);
474 #endif
475 	}
476 }
477 
478 preserve()
479 {
480 
481 #ifdef VMUNIX
482 	tflush();
483 #endif
484 	synctmp();
485 	pid = fork();
486 	if (pid < 0)
487 		return (0);
488 	if (pid == 0) {
489 		close(0);
490 		dup(tfile);
491 		execl(EXPRESERVE, "expreserve", (char *) 0);
492 		exit(1);
493 	}
494 	waitfor();
495 	if (rpid == pid && status == 0)
496 		return (1);
497 	return (0);
498 }
499 
500 #ifndef V6
501 exit(i)
502 	int i;
503 {
504 
505 # ifdef TRACE
506 	if (trace)
507 		fclose(trace);
508 # endif
509 	_exit(i);
510 }
511 #endif
512 
513 /*
514  * Return last component of unix path name p.
515  */
516 char *
517 tailpath(p)
518 register char *p;
519 {
520 	register char *r;
521 
522 	for (r=p; *p; p++)
523 		if (*p == '/')
524 			r = p+1;
525 	return(r);
526 }
527