xref: /freebsd/bin/ed/main.c (revision 42c159fe388a3765f69860c84183700af37aca8a)
1 /* main.c: This file contains the main control and user-interface routines
2    for the ed line editor. */
3 /*-
4  * Copyright (c) 1993 Andrew Moore, Talke Studio.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #ifndef lint
30 static const char copyright[] =
31 "@(#) Copyright (c) 1993 Andrew Moore, Talke Studio. \n\
32  All rights reserved.\n";
33 #endif /* not lint */
34 
35 #ifndef lint
36 static const char rcsid[] =
37   "$FreeBSD$";
38 #endif /* not lint */
39 
40 /*
41  * CREDITS
42  *
43  *	This program is based on the editor algorithm described in
44  *	Brian W. Kernighan and P. J. Plauger's book "Software Tools
45  *	in Pascal," Addison-Wesley, 1981.
46  *
47  *	The buffering algorithm is attributed to Rodney Ruddock of
48  *	the University of Guelph, Guelph, Ontario.
49  *
50  *	The cbc.c encryption code is adapted from
51  *	the bdes program by Matt Bishop of Dartmouth College,
52  *	Hanover, NH.
53  *
54  */
55 
56 #include <sys/types.h>
57 
58 #include <sys/ioctl.h>
59 #include <sys/wait.h>
60 #include <ctype.h>
61 #include <locale.h>
62 #include <pwd.h>
63 #include <setjmp.h>
64 
65 #include "ed.h"
66 
67 
68 #ifdef _POSIX_SOURCE
69 sigjmp_buf env;
70 #else
71 jmp_buf env;
72 #endif
73 
74 /* static buffers */
75 char stdinbuf[1];		/* stdin buffer */
76 char *shcmd;			/* shell command buffer */
77 int shcmdsz;			/* shell command buffer size */
78 int shcmdi;			/* shell command buffer index */
79 char *ibuf;			/* ed command-line buffer */
80 int ibufsz;			/* ed command-line buffer size */
81 char *ibufp;			/* pointer to ed command-line buffer */
82 
83 /* global flags */
84 int des = 0;			/* if set, use crypt(3) for i/o */
85 int garrulous = 0;		/* if set, print all error messages */
86 int isbinary;			/* if set, buffer contains ASCII NULs */
87 int isglobal;			/* if set, doing a global command */
88 int modified;			/* if set, buffer modified since last write */
89 int mutex = 0;			/* if set, signals set "sigflags" */
90 int red = 0;			/* if set, restrict shell/directory access */
91 int scripted = 0;		/* if set, suppress diagnostics */
92 int sigflags = 0;		/* if set, signals received while mutex set */
93 int sigactive = 0;		/* if set, signal handlers are enabled */
94 
95 char old_filename[PATH_MAX] = "";	/* default filename */
96 long current_addr;		/* current address in editor buffer */
97 long addr_last;			/* last address in editor buffer */
98 int lineno;			/* script line number */
99 const char *prompt;		/* command-line prompt */
100 const char *dps = "*";		/* default command-line prompt */
101 
102 const char usage[] = "usage: %s [-] [-sx] [-p string] [name]\n";
103 
104 /* ed: line editor */
105 int
106 main(int argc, char *argv[])
107 {
108 	int c, n;
109 	long status = 0;
110 #if __GNUC__
111 	/* Avoid longjmp clobbering */
112 	(void) &argc;
113 	(void) &argv;
114 #endif
115 
116 	(void)setlocale(LC_ALL, "");
117 
118 	red = (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
119 top:
120 	while ((c = getopt(argc, argv, "p:sx")) != -1)
121 		switch(c) {
122 		case 'p':				/* set prompt */
123 			prompt = optarg;
124 			break;
125 		case 's':				/* run script */
126 			scripted = 1;
127 			break;
128 		case 'x':				/* use crypt */
129 #ifdef DES
130 			des = get_keyword();
131 #else
132 			fprintf(stderr, "crypt unavailable\n?\n");
133 #endif
134 			break;
135 
136 		default:
137 			fprintf(stderr, usage, argv[0]);
138 			exit(1);
139 		}
140 	argv += optind;
141 	argc -= optind;
142 	if (argc && **argv == '-') {
143 		scripted = 1;
144 		if (argc > 1) {
145 			optind = 1;
146 			goto top;
147 		}
148 		argv++;
149 		argc--;
150 	}
151 	/* assert: reliable signals! */
152 #ifdef SIGWINCH
153 	handle_winch(SIGWINCH);
154 	if (isatty(0)) signal(SIGWINCH, handle_winch);
155 #endif
156 	signal(SIGHUP, signal_hup);
157 	signal(SIGQUIT, SIG_IGN);
158 	signal(SIGINT, signal_int);
159 #ifdef _POSIX_SOURCE
160 	if ((status = sigsetjmp(env, 1)))
161 #else
162 	if ((status = setjmp(env)))
163 #endif
164 	{
165 		fputs("\n?\n", stderr);
166 		errmsg = "interrupt";
167 	} else {
168 		init_buffers();
169 		sigactive = 1;			/* enable signal handlers */
170 		if (argc && **argv && is_legal_filename(*argv)) {
171 			if (read_file(*argv, 0) < 0 && !isatty(0))
172 				quit(2);
173 			else if (**argv != '!')
174 				if (strlcpy(old_filename, *argv, sizeof(old_filename))
175 				    >= sizeof(old_filename))
176 					quit(2);
177 		} else if (argc) {
178 			fputs("?\n", stderr);
179 			if (**argv == '\0')
180 				errmsg = "invalid filename";
181 			if (!isatty(0))
182 				quit(2);
183 		}
184 	}
185 	for (;;) {
186 		if (status < 0 && garrulous)
187 			fprintf(stderr, "%s\n", errmsg);
188 		if (prompt) {
189 			printf("%s", prompt);
190 			fflush(stdout);
191 		}
192 		if ((n = get_tty_line()) < 0) {
193 			status = ERR;
194 			continue;
195 		} else if (n == 0) {
196 			if (modified && !scripted) {
197 				fputs("?\n", stderr);
198 				errmsg = "warning: file modified";
199 				if (!isatty(0)) {
200 					fprintf(stderr, garrulous ?
201 					    "script, line %d: %s\n" :
202 					    "", lineno, errmsg);
203 					quit(2);
204 				}
205 				clearerr(stdin);
206 				modified = 0;
207 				status = EMOD;
208 				continue;
209 			} else
210 				quit(0);
211 		} else if (ibuf[n - 1] != '\n') {
212 			/* discard line */
213 			errmsg = "unexpected end-of-file";
214 			clearerr(stdin);
215 			status = ERR;
216 			continue;
217 		}
218 		isglobal = 0;
219 		if ((status = extract_addr_range()) >= 0 &&
220 		    (status = exec_command()) >= 0)
221 			if (!status ||
222 			    (status = display_lines(current_addr, current_addr,
223 			        status)) >= 0)
224 				continue;
225 		switch (status) {
226 		case EOF:
227 			quit(0);
228 		case EMOD:
229 			modified = 0;
230 			fputs("?\n", stderr);		/* give warning */
231 			errmsg = "warning: file modified";
232 			if (!isatty(0)) {
233 				fprintf(stderr, garrulous ?
234 				    "script, line %d: %s\n" :
235 				    "", lineno, errmsg);
236 				quit(2);
237 			}
238 			break;
239 		case FATAL:
240 			if (!isatty(0))
241 				fprintf(stderr, garrulous ?
242 				    "script, line %d: %s\n" : "",
243 				    lineno, errmsg);
244 			else
245 				fprintf(stderr, garrulous ? "%s\n" : "",
246 				    errmsg);
247 			quit(3);
248 		default:
249 			fputs("?\n", stderr);
250 			if (!isatty(0)) {
251 				fprintf(stderr, garrulous ?
252 				    "script, line %d: %s\n" : "",
253 				    lineno, errmsg);
254 				quit(2);
255 			}
256 			break;
257 		}
258 	}
259 	/*NOTREACHED*/
260 }
261 
262 long first_addr, second_addr, addr_cnt;
263 
264 /* extract_addr_range: get line addresses from the command buffer until an
265    illegal address is seen; return status */
266 int
267 extract_addr_range(void)
268 {
269 	long addr;
270 
271 	addr_cnt = 0;
272 	first_addr = second_addr = current_addr;
273 	while ((addr = next_addr()) >= 0) {
274 		addr_cnt++;
275 		first_addr = second_addr;
276 		second_addr = addr;
277 		if (*ibufp != ',' && *ibufp != ';')
278 			break;
279 		else if (*ibufp++ == ';')
280 			current_addr = addr;
281 	}
282 	if ((addr_cnt = min(addr_cnt, 2)) == 1 || second_addr != addr)
283 		first_addr = second_addr;
284 	return (addr == ERR) ? ERR : 0;
285 }
286 
287 
288 #define SKIP_BLANKS() while (isspace((unsigned char)*ibufp) && *ibufp != '\n') ibufp++
289 
290 #define MUST_BE_FIRST() do {					\
291 	if (!first) {						\
292 		errmsg = "invalid address";			\
293 		return ERR;					\
294 	}							\
295 } while (0);
296 
297 /*  next_addr: return the next line address in the command buffer */
298 long
299 next_addr(void)
300 {
301 	const char *hd;
302 	long addr = current_addr;
303 	long n;
304 	int first = 1;
305 	int c;
306 
307 	SKIP_BLANKS();
308 	for (hd = ibufp;; first = 0)
309 		switch (c = *ibufp) {
310 		case '+':
311 		case '\t':
312 		case ' ':
313 		case '-':
314 		case '^':
315 			ibufp++;
316 			SKIP_BLANKS();
317 			if (isdigit((unsigned char)*ibufp)) {
318 				STRTOL(n, ibufp);
319 				addr += (c == '-' || c == '^') ? -n : n;
320 			} else if (!isspace((unsigned char)c))
321 				addr += (c == '-' || c == '^') ? -1 : 1;
322 			break;
323 		case '0': case '1': case '2':
324 		case '3': case '4': case '5':
325 		case '6': case '7': case '8': case '9':
326 			MUST_BE_FIRST();
327 			STRTOL(addr, ibufp);
328 			break;
329 		case '.':
330 		case '$':
331 			MUST_BE_FIRST();
332 			ibufp++;
333 			addr = (c == '.') ? current_addr : addr_last;
334 			break;
335 		case '/':
336 		case '?':
337 			MUST_BE_FIRST();
338 			if ((addr = get_matching_node_addr(
339 			    get_compiled_pattern(), c == '/')) < 0)
340 				return ERR;
341 			else if (c == *ibufp)
342 				ibufp++;
343 			break;
344 		case '\'':
345 			MUST_BE_FIRST();
346 			ibufp++;
347 			if ((addr = get_marked_node_addr(*ibufp++)) < 0)
348 				return ERR;
349 			break;
350 		case '%':
351 		case ',':
352 		case ';':
353 			if (first) {
354 				ibufp++;
355 				addr_cnt++;
356 				second_addr = (c == ';') ? current_addr : 1;
357 				addr = addr_last;
358 				break;
359 			}
360 			/* FALL THROUGH */
361 		default:
362 			if (ibufp == hd)
363 				return EOF;
364 			else if (addr < 0 || addr_last < addr) {
365 				errmsg = "invalid address";
366 				return ERR;
367 			} else
368 				return addr;
369 		}
370 	/* NOTREACHED */
371 }
372 
373 
374 #ifdef BACKWARDS
375 /* GET_THIRD_ADDR: get a legal address from the command buffer */
376 #define GET_THIRD_ADDR(addr) \
377 { \
378 	long ol1, ol2; \
379 \
380 	ol1 = first_addr, ol2 = second_addr; \
381 	if (extract_addr_range() < 0) \
382 		return ERR; \
383 	else if (addr_cnt == 0) { \
384 		errmsg = "destination expected"; \
385 		return ERR; \
386 	} else if (second_addr < 0 || addr_last < second_addr) { \
387 		errmsg = "invalid address"; \
388 		return ERR; \
389 	} \
390 	addr = second_addr; \
391 	first_addr = ol1, second_addr = ol2; \
392 }
393 #else	/* BACKWARDS */
394 /* GET_THIRD_ADDR: get a legal address from the command buffer */
395 #define GET_THIRD_ADDR(addr) \
396 { \
397 	long ol1, ol2; \
398 \
399 	ol1 = first_addr, ol2 = second_addr; \
400 	if (extract_addr_range() < 0) \
401 		return ERR; \
402 	if (second_addr < 0 || addr_last < second_addr) { \
403 		errmsg = "invalid address"; \
404 		return ERR; \
405 	} \
406 	addr = second_addr; \
407 	first_addr = ol1, second_addr = ol2; \
408 }
409 #endif
410 
411 
412 /* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
413 #define GET_COMMAND_SUFFIX() { \
414 	int done = 0; \
415 	do { \
416 		switch(*ibufp) { \
417 		case 'p': \
418 			gflag |= GPR, ibufp++; \
419 			break; \
420 		case 'l': \
421 			gflag |= GLS, ibufp++; \
422 			break; \
423 		case 'n': \
424 			gflag |= GNP, ibufp++; \
425 			break; \
426 		default: \
427 			done++; \
428 		} \
429 	} while (!done); \
430 	if (*ibufp++ != '\n') { \
431 		errmsg = "invalid command suffix"; \
432 		return ERR; \
433 	} \
434 }
435 
436 
437 /* sflags */
438 #define SGG 001		/* complement previous global substitute suffix */
439 #define SGP 002		/* complement previous print suffix */
440 #define SGR 004		/* use last regex instead of last pat */
441 #define SGF 010		/* repeat last substitution */
442 
443 int patlock = 0;	/* if set, pattern not freed by get_compiled_pattern() */
444 
445 long rows = 22;		/* scroll length: ws_row - 2 */
446 
447 /* exec_command: execute the next command in command buffer; return print
448    request, if any */
449 int
450 exec_command(void)
451 {
452 	extern long u_current_addr;
453 	extern long u_addr_last;
454 
455 	static pattern_t *pat = NULL;
456 	static int sgflag = 0;
457 	static long sgnum = 0;
458 
459 	pattern_t *tpat;
460 	char *fnp;
461 	int gflag = 0;
462 	int sflags = 0;
463 	long addr = 0;
464 	int n = 0;
465 	int c;
466 
467 	SKIP_BLANKS();
468 	switch(c = *ibufp++) {
469 	case 'a':
470 		GET_COMMAND_SUFFIX();
471 		if (!isglobal) clear_undo_stack();
472 		if (append_lines(second_addr) < 0)
473 			return ERR;
474 		break;
475 	case 'c':
476 		if (check_addr_range(current_addr, current_addr) < 0)
477 			return ERR;
478 		GET_COMMAND_SUFFIX();
479 		if (!isglobal) clear_undo_stack();
480 		if (delete_lines(first_addr, second_addr) < 0 ||
481 		    append_lines(current_addr) < 0)
482 			return ERR;
483 		break;
484 	case 'd':
485 		if (check_addr_range(current_addr, current_addr) < 0)
486 			return ERR;
487 		GET_COMMAND_SUFFIX();
488 		if (!isglobal) clear_undo_stack();
489 		if (delete_lines(first_addr, second_addr) < 0)
490 			return ERR;
491 		else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
492 			current_addr = addr;
493 		break;
494 	case 'e':
495 		if (modified && !scripted)
496 			return EMOD;
497 		/* fall through */
498 	case 'E':
499 		if (addr_cnt > 0) {
500 			errmsg = "unexpected address";
501 			return ERR;
502 		} else if (!isspace((unsigned char)*ibufp)) {
503 			errmsg = "unexpected command suffix";
504 			return ERR;
505 		} else if ((fnp = get_filename()) == NULL)
506 			return ERR;
507 		GET_COMMAND_SUFFIX();
508 		if (delete_lines(1, addr_last) < 0)
509 			return ERR;
510 		clear_undo_stack();
511 		if (close_sbuf() < 0)
512 			return ERR;
513 		else if (open_sbuf() < 0)
514 			return FATAL;
515 		if (*fnp && *fnp != '!') strcpy(old_filename, fnp);
516 #ifdef BACKWARDS
517 		if (*fnp == '\0' && *old_filename == '\0') {
518 			errmsg = "no current filename";
519 			return ERR;
520 		}
521 #endif
522 		if (read_file(*fnp ? fnp : old_filename, 0) < 0)
523 			return ERR;
524 		clear_undo_stack();
525 		modified = 0;
526 		u_current_addr = u_addr_last = -1;
527 		break;
528 	case 'f':
529 		if (addr_cnt > 0) {
530 			errmsg = "unexpected address";
531 			return ERR;
532 		} else if (!isspace((unsigned char)*ibufp)) {
533 			errmsg = "unexpected command suffix";
534 			return ERR;
535 		} else if ((fnp = get_filename()) == NULL)
536 			return ERR;
537 		else if (*fnp == '!') {
538 			errmsg = "invalid redirection";
539 			return ERR;
540 		}
541 		GET_COMMAND_SUFFIX();
542 		if (*fnp) strcpy(old_filename, fnp);
543 		printf("%s\n", strip_escapes(old_filename));
544 		break;
545 	case 'g':
546 	case 'v':
547 	case 'G':
548 	case 'V':
549 		if (isglobal) {
550 			errmsg = "cannot nest global commands";
551 			return ERR;
552 		} else if (check_addr_range(1, addr_last) < 0)
553 			return ERR;
554 		else if (build_active_list(c == 'g' || c == 'G') < 0)
555 			return ERR;
556 		else if ((n = (c == 'G' || c == 'V')))
557 			GET_COMMAND_SUFFIX();
558 		isglobal++;
559 		if (exec_global(n, gflag) < 0)
560 			return ERR;
561 		break;
562 	case 'h':
563 		if (addr_cnt > 0) {
564 			errmsg = "unexpected address";
565 			return ERR;
566 		}
567 		GET_COMMAND_SUFFIX();
568 		if (*errmsg) fprintf(stderr, "%s\n", errmsg);
569 		break;
570 	case 'H':
571 		if (addr_cnt > 0) {
572 			errmsg = "unexpected address";
573 			return ERR;
574 		}
575 		GET_COMMAND_SUFFIX();
576 		if ((garrulous = 1 - garrulous) && *errmsg)
577 			fprintf(stderr, "%s\n", errmsg);
578 		break;
579 	case 'i':
580 		if (second_addr == 0) {
581 			errmsg = "invalid address";
582 			return ERR;
583 		}
584 		GET_COMMAND_SUFFIX();
585 		if (!isglobal) clear_undo_stack();
586 		if (append_lines(second_addr - 1) < 0)
587 			return ERR;
588 		break;
589 	case 'j':
590 		if (check_addr_range(current_addr, current_addr + 1) < 0)
591 			return ERR;
592 		GET_COMMAND_SUFFIX();
593 		if (!isglobal) clear_undo_stack();
594 		if (first_addr != second_addr &&
595 		    join_lines(first_addr, second_addr) < 0)
596 			return ERR;
597 		break;
598 	case 'k':
599 		c = *ibufp++;
600 		if (second_addr == 0) {
601 			errmsg = "invalid address";
602 			return ERR;
603 		}
604 		GET_COMMAND_SUFFIX();
605 		if (mark_line_node(get_addressed_line_node(second_addr), c) < 0)
606 			return ERR;
607 		break;
608 	case 'l':
609 		if (check_addr_range(current_addr, current_addr) < 0)
610 			return ERR;
611 		GET_COMMAND_SUFFIX();
612 		if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
613 			return ERR;
614 		gflag = 0;
615 		break;
616 	case 'm':
617 		if (check_addr_range(current_addr, current_addr) < 0)
618 			return ERR;
619 		GET_THIRD_ADDR(addr);
620 		if (first_addr <= addr && addr < second_addr) {
621 			errmsg = "invalid destination";
622 			return ERR;
623 		}
624 		GET_COMMAND_SUFFIX();
625 		if (!isglobal) clear_undo_stack();
626 		if (move_lines(addr) < 0)
627 			return ERR;
628 		break;
629 	case 'n':
630 		if (check_addr_range(current_addr, current_addr) < 0)
631 			return ERR;
632 		GET_COMMAND_SUFFIX();
633 		if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
634 			return ERR;
635 		gflag = 0;
636 		break;
637 	case 'p':
638 		if (check_addr_range(current_addr, current_addr) < 0)
639 			return ERR;
640 		GET_COMMAND_SUFFIX();
641 		if (display_lines(first_addr, second_addr, gflag | GPR) < 0)
642 			return ERR;
643 		gflag = 0;
644 		break;
645 	case 'P':
646 		if (addr_cnt > 0) {
647 			errmsg = "unexpected address";
648 			return ERR;
649 		}
650 		GET_COMMAND_SUFFIX();
651 		prompt = prompt ? NULL : optarg ? optarg : dps;
652 		break;
653 	case 'q':
654 	case 'Q':
655 		if (addr_cnt > 0) {
656 			errmsg = "unexpected address";
657 			return ERR;
658 		}
659 		GET_COMMAND_SUFFIX();
660 		gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
661 		break;
662 	case 'r':
663 		if (!isspace((unsigned char)*ibufp)) {
664 			errmsg = "unexpected command suffix";
665 			return ERR;
666 		} else if (addr_cnt == 0)
667 			second_addr = addr_last;
668 		if ((fnp = get_filename()) == NULL)
669 			return ERR;
670 		GET_COMMAND_SUFFIX();
671 		if (!isglobal) clear_undo_stack();
672 		if (*old_filename == '\0' && *fnp != '!')
673 			strcpy(old_filename, fnp);
674 #ifdef BACKWARDS
675 		if (*fnp == '\0' && *old_filename == '\0') {
676 			errmsg = "no current filename";
677 			return ERR;
678 		}
679 #endif
680 		if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
681 			return ERR;
682 		else if (addr && addr != addr_last)
683 			modified = 1;
684 		break;
685 	case 's':
686 		do {
687 			switch(*ibufp) {
688 			case '\n':
689 				sflags |=SGF;
690 				break;
691 			case 'g':
692 				sflags |= SGG;
693 				ibufp++;
694 				break;
695 			case 'p':
696 				sflags |= SGP;
697 				ibufp++;
698 				break;
699 			case 'r':
700 				sflags |= SGR;
701 				ibufp++;
702 				break;
703 			case '0': case '1': case '2': case '3': case '4':
704 			case '5': case '6': case '7': case '8': case '9':
705 				STRTOL(sgnum, ibufp);
706 				sflags |= SGF;
707 				sgflag &= ~GSG;		/* override GSG */
708 				break;
709 			default:
710 				if (sflags) {
711 					errmsg = "invalid command suffix";
712 					return ERR;
713 				}
714 			}
715 		} while (sflags && *ibufp != '\n');
716 		if (sflags && !pat) {
717 			errmsg = "no previous substitution";
718 			return ERR;
719 		} else if (sflags & SGG)
720 			sgnum = 0;		/* override numeric arg */
721 		if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
722 			errmsg = "invalid pattern delimiter";
723 			return ERR;
724 		}
725 		tpat = pat;
726 		SPL1();
727 		if ((!sflags || (sflags & SGR)) &&
728 		    (tpat = get_compiled_pattern()) == NULL) {
729 		 	SPL0();
730 			return ERR;
731 		} else if (tpat != pat) {
732 			if (pat) {
733 				regfree(pat);
734 				free(pat);
735 			}
736 			pat = tpat;
737 			patlock = 1;		/* reserve pattern */
738 		}
739 		SPL0();
740 		if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
741 			return ERR;
742 		else if (isglobal)
743 			sgflag |= GLB;
744 		else
745 			sgflag &= ~GLB;
746 		if (sflags & SGG)
747 			sgflag ^= GSG;
748 		if (sflags & SGP)
749 			sgflag ^= GPR, sgflag &= ~(GLS | GNP);
750 		do {
751 			switch(*ibufp) {
752 			case 'p':
753 				sgflag |= GPR, ibufp++;
754 				break;
755 			case 'l':
756 				sgflag |= GLS, ibufp++;
757 				break;
758 			case 'n':
759 				sgflag |= GNP, ibufp++;
760 				break;
761 			default:
762 				n++;
763 			}
764 		} while (!n);
765 		if (check_addr_range(current_addr, current_addr) < 0)
766 			return ERR;
767 		GET_COMMAND_SUFFIX();
768 		if (!isglobal) clear_undo_stack();
769 		if (search_and_replace(pat, sgflag, sgnum) < 0)
770 			return ERR;
771 		break;
772 	case 't':
773 		if (check_addr_range(current_addr, current_addr) < 0)
774 			return ERR;
775 		GET_THIRD_ADDR(addr);
776 		GET_COMMAND_SUFFIX();
777 		if (!isglobal) clear_undo_stack();
778 		if (copy_lines(addr) < 0)
779 			return ERR;
780 		break;
781 	case 'u':
782 		if (addr_cnt > 0) {
783 			errmsg = "unexpected address";
784 			return ERR;
785 		}
786 		GET_COMMAND_SUFFIX();
787 		if (pop_undo_stack() < 0)
788 			return ERR;
789 		break;
790 	case 'w':
791 	case 'W':
792 		if ((n = *ibufp) == 'q' || n == 'Q') {
793 			gflag = EOF;
794 			ibufp++;
795 		}
796 		if (!isspace((unsigned char)*ibufp)) {
797 			errmsg = "unexpected command suffix";
798 			return ERR;
799 		} else if ((fnp = get_filename()) == NULL)
800 			return ERR;
801 		if (addr_cnt == 0 && !addr_last)
802 			first_addr = second_addr = 0;
803 		else if (check_addr_range(1, addr_last) < 0)
804 			return ERR;
805 		GET_COMMAND_SUFFIX();
806 		if (*old_filename == '\0' && *fnp != '!')
807 			strcpy(old_filename, fnp);
808 #ifdef BACKWARDS
809 		if (*fnp == '\0' && *old_filename == '\0') {
810 			errmsg = "no current filename";
811 			return ERR;
812 		}
813 #endif
814 		if ((addr = write_file(*fnp ? fnp : old_filename,
815 		    (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
816 			return ERR;
817 		else if (addr == addr_last)
818 			modified = 0;
819 		else if (modified && !scripted && n == 'q')
820 			gflag = EMOD;
821 		break;
822 	case 'x':
823 		if (addr_cnt > 0) {
824 			errmsg = "unexpected address";
825 			return ERR;
826 		}
827 		GET_COMMAND_SUFFIX();
828 #ifdef DES
829 		des = get_keyword();
830 #else
831 		errmsg = "crypt unavailable";
832 		return ERR;
833 #endif
834 		break;
835 	case 'z':
836 #ifdef BACKWARDS
837 		if (check_addr_range(first_addr = 1, current_addr + 1) < 0)
838 #else
839 		if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0)
840 #endif
841 			return ERR;
842 		else if ('0' < *ibufp && *ibufp <= '9')
843 			STRTOL(rows, ibufp);
844 		GET_COMMAND_SUFFIX();
845 		if (display_lines(second_addr, min(addr_last,
846 		    second_addr + rows), gflag) < 0)
847 			return ERR;
848 		gflag = 0;
849 		break;
850 	case '=':
851 		GET_COMMAND_SUFFIX();
852 		printf("%ld\n", addr_cnt ? second_addr : addr_last);
853 		break;
854 	case '!':
855 		if (addr_cnt > 0) {
856 			errmsg = "unexpected address";
857 			return ERR;
858 		} else if ((sflags = get_shell_command()) < 0)
859 			return ERR;
860 		GET_COMMAND_SUFFIX();
861 		if (sflags) printf("%s\n", shcmd + 1);
862 		system(shcmd + 1);
863 		if (!scripted) printf("!\n");
864 		break;
865 	case '\n':
866 #ifdef BACKWARDS
867 		if (check_addr_range(first_addr = 1, current_addr + 1) < 0
868 #else
869 		if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0
870 #endif
871 		 || display_lines(second_addr, second_addr, 0) < 0)
872 			return ERR;
873 		break;
874 	default:
875 		errmsg = "unknown command";
876 		return ERR;
877 	}
878 	return gflag;
879 }
880 
881 
882 /* check_addr_range: return status of address range check */
883 int
884 check_addr_range(long n, long m)
885 {
886 	if (addr_cnt == 0) {
887 		first_addr = n;
888 		second_addr = m;
889 	}
890 	if (first_addr > second_addr || 1 > first_addr ||
891 	    second_addr > addr_last) {
892 		errmsg = "invalid address";
893 		return ERR;
894 	}
895 	return 0;
896 }
897 
898 
899 /* get_matching_node_addr: return the address of the next line matching a
900    pattern in a given direction.  wrap around begin/end of editor buffer if
901    necessary */
902 long
903 get_matching_node_addr(pattern_t *pat, int dir)
904 {
905 	char *s;
906 	long n = current_addr;
907 	line_t *lp;
908 
909 	if (!pat) return ERR;
910 	do {
911 	       if ((n = dir ? INC_MOD(n, addr_last) : DEC_MOD(n, addr_last))) {
912 			lp = get_addressed_line_node(n);
913 			if ((s = get_sbuf_line(lp)) == NULL)
914 				return ERR;
915 			if (isbinary)
916 				NUL_TO_NEWLINE(s, lp->len);
917 			if (!regexec(pat, s, 0, NULL, 0))
918 				return n;
919 	       }
920 	} while (n != current_addr);
921 	errmsg = "no match";
922 	return  ERR;
923 }
924 
925 
926 /* get_filename: return pointer to copy of filename in the command buffer */
927 char *
928 get_filename(void)
929 {
930 	static char *file = NULL;
931 	static int filesz = 0;
932 
933 	int n;
934 
935 	if (*ibufp != '\n') {
936 		SKIP_BLANKS();
937 		if (*ibufp == '\n') {
938 			errmsg = "invalid filename";
939 			return NULL;
940 		} else if ((ibufp = get_extended_line(&n, 1)) == NULL)
941 			return NULL;
942 		else if (*ibufp == '!') {
943 			ibufp++;
944 			if ((n = get_shell_command()) < 0)
945 				return NULL;
946 			if (n)
947 				printf("%s\n", shcmd + 1);
948 			return shcmd;
949 		} else if (n > PATH_MAX - 1) {
950 			errmsg = "filename too long";
951 			return  NULL;
952 		}
953 	}
954 #ifndef BACKWARDS
955 	else if (*old_filename == '\0') {
956 		errmsg = "no current filename";
957 		return  NULL;
958 	}
959 #endif
960 	REALLOC(file, filesz, PATH_MAX, NULL);
961 	for (n = 0; *ibufp != '\n';)
962 		file[n++] = *ibufp++;
963 	file[n] = '\0';
964 	return is_legal_filename(file) ? file : NULL;
965 }
966 
967 
968 /* get_shell_command: read a shell command from stdin; return substitution
969    status */
970 int
971 get_shell_command(void)
972 {
973 	static char *buf = NULL;
974 	static int n = 0;
975 
976 	char *s;			/* substitution char pointer */
977 	int i = 0;
978 	int j = 0;
979 
980 	if (red) {
981 		errmsg = "shell access restricted";
982 		return ERR;
983 	} else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
984 		return ERR;
985 	REALLOC(buf, n, j + 1, ERR);
986 	buf[i++] = '!';			/* prefix command w/ bang */
987 	while (*ibufp != '\n')
988 		switch (*ibufp) {
989 		default:
990 			REALLOC(buf, n, i + 2, ERR);
991 			buf[i++] = *ibufp;
992 			if (*ibufp++ == '\\')
993 				buf[i++] = *ibufp++;
994 			break;
995 		case '!':
996 			if (s != ibufp) {
997 				REALLOC(buf, n, i + 1, ERR);
998 				buf[i++] = *ibufp++;
999 			}
1000 #ifdef BACKWARDS
1001 			else if (shcmd == NULL || *(shcmd + 1) == '\0')
1002 #else
1003 			else if (shcmd == NULL)
1004 #endif
1005 			{
1006 				errmsg = "no previous command";
1007 				return ERR;
1008 			} else {
1009 				REALLOC(buf, n, i + shcmdi, ERR);
1010 				for (s = shcmd + 1; s < shcmd + shcmdi;)
1011 					buf[i++] = *s++;
1012 				s = ibufp++;
1013 			}
1014 			break;
1015 		case '%':
1016 			if (*old_filename  == '\0') {
1017 				errmsg = "no current filename";
1018 				return ERR;
1019 			}
1020 			j = strlen(s = strip_escapes(old_filename));
1021 			REALLOC(buf, n, i + j, ERR);
1022 			while (j--)
1023 				buf[i++] = *s++;
1024 			s = ibufp++;
1025 			break;
1026 		}
1027 	REALLOC(shcmd, shcmdsz, i + 1, ERR);
1028 	memcpy(shcmd, buf, i);
1029 	shcmd[shcmdi = i] = '\0';
1030 	return *s == '!' || *s == '%';
1031 }
1032 
1033 
1034 /* append_lines: insert text from stdin to after line n; stop when either a
1035    single period is read or EOF; return status */
1036 int
1037 append_lines(long n)
1038 {
1039 	int l;
1040 	const char *lp = ibuf;
1041 	const char *eot;
1042 	undo_t *up = NULL;
1043 
1044 	for (current_addr = n;;) {
1045 		if (!isglobal) {
1046 			if ((l = get_tty_line()) < 0)
1047 				return ERR;
1048 			else if (l == 0 || ibuf[l - 1] != '\n') {
1049 				clearerr(stdin);
1050 				return  l ? EOF : 0;
1051 			}
1052 			lp = ibuf;
1053 		} else if (*(lp = ibufp) == '\0')
1054 			return 0;
1055 		else {
1056 			while (*ibufp++ != '\n')
1057 				;
1058 			l = ibufp - lp;
1059 		}
1060 		if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1061 			return 0;
1062 		}
1063 		eot = lp + l;
1064 		SPL1();
1065 		do {
1066 			if ((lp = put_sbuf_line(lp)) == NULL) {
1067 				SPL0();
1068 				return ERR;
1069 			} else if (up)
1070 				up->t = get_addressed_line_node(current_addr);
1071 			else if ((up = push_undo_stack(UADD, current_addr,
1072 			    current_addr)) == NULL) {
1073 				SPL0();
1074 				return ERR;
1075 			}
1076 		} while (lp != eot);
1077 		modified = 1;
1078 		SPL0();
1079 	}
1080 	/* NOTREACHED */
1081 }
1082 
1083 
1084 /* join_lines: replace a range of lines with the joined text of those lines */
1085 int
1086 join_lines(long from, long to)
1087 {
1088 	static char *buf = NULL;
1089 	static int n;
1090 
1091 	char *s;
1092 	int size = 0;
1093 	line_t *bp, *ep;
1094 
1095 	ep = get_addressed_line_node(INC_MOD(to, addr_last));
1096 	bp = get_addressed_line_node(from);
1097 	for (; bp != ep; bp = bp->q_forw) {
1098 		if ((s = get_sbuf_line(bp)) == NULL)
1099 			return ERR;
1100 		REALLOC(buf, n, size + bp->len, ERR);
1101 		memcpy(buf + size, s, bp->len);
1102 		size += bp->len;
1103 	}
1104 	REALLOC(buf, n, size + 2, ERR);
1105 	memcpy(buf + size, "\n", 2);
1106 	if (delete_lines(from, to) < 0)
1107 		return ERR;
1108 	current_addr = from - 1;
1109 	SPL1();
1110 	if (put_sbuf_line(buf) == NULL ||
1111 	    push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1112 		SPL0();
1113 		return ERR;
1114 	}
1115 	modified = 1;
1116 	SPL0();
1117 	return 0;
1118 }
1119 
1120 
1121 /* move_lines: move a range of lines */
1122 int
1123 move_lines(long addr)
1124 {
1125 	line_t *b1, *a1, *b2, *a2;
1126 	long n = INC_MOD(second_addr, addr_last);
1127 	long p = first_addr - 1;
1128 	int done = (addr == first_addr - 1 || addr == second_addr);
1129 
1130 	SPL1();
1131 	if (done) {
1132 		a2 = get_addressed_line_node(n);
1133 		b2 = get_addressed_line_node(p);
1134 		current_addr = second_addr;
1135 	} else if (push_undo_stack(UMOV, p, n) == NULL ||
1136 	    push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1137 		SPL0();
1138 		return ERR;
1139 	} else {
1140 		a1 = get_addressed_line_node(n);
1141 		if (addr < first_addr) {
1142 			b1 = get_addressed_line_node(p);
1143 			b2 = get_addressed_line_node(addr);
1144 					/* this get_addressed_line_node last! */
1145 		} else {
1146 			b2 = get_addressed_line_node(addr);
1147 			b1 = get_addressed_line_node(p);
1148 					/* this get_addressed_line_node last! */
1149 		}
1150 		a2 = b2->q_forw;
1151 		REQUE(b2, b1->q_forw);
1152 		REQUE(a1->q_back, a2);
1153 		REQUE(b1, a1);
1154 		current_addr = addr + ((addr < first_addr) ?
1155 		    second_addr - first_addr + 1 : 0);
1156 	}
1157 	if (isglobal)
1158 		unset_active_nodes(b2->q_forw, a2);
1159 	modified = 1;
1160 	SPL0();
1161 	return 0;
1162 }
1163 
1164 
1165 /* copy_lines: copy a range of lines; return status */
1166 int
1167 copy_lines(long addr)
1168 {
1169 	line_t *lp, *np = get_addressed_line_node(first_addr);
1170 	undo_t *up = NULL;
1171 	long n = second_addr - first_addr + 1;
1172 	long m = 0;
1173 
1174 	current_addr = addr;
1175 	if (first_addr <= addr && addr < second_addr) {
1176 		n =  addr - first_addr + 1;
1177 		m = second_addr - addr;
1178 	}
1179 	for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1180 		for (; n-- > 0; np = np->q_forw) {
1181 			SPL1();
1182 			if ((lp = dup_line_node(np)) == NULL) {
1183 				SPL0();
1184 				return ERR;
1185 			}
1186 			add_line_node(lp);
1187 			if (up)
1188 				up->t = lp;
1189 			else if ((up = push_undo_stack(UADD, current_addr,
1190 			    current_addr)) == NULL) {
1191 				SPL0();
1192 				return ERR;
1193 			}
1194 			modified = 1;
1195 			SPL0();
1196 		}
1197 	return 0;
1198 }
1199 
1200 
1201 /* delete_lines: delete a range of lines */
1202 int
1203 delete_lines(long from, long to)
1204 {
1205 	line_t *n, *p;
1206 
1207 	SPL1();
1208 	if (push_undo_stack(UDEL, from, to) == NULL) {
1209 		SPL0();
1210 		return ERR;
1211 	}
1212 	n = get_addressed_line_node(INC_MOD(to, addr_last));
1213 	p = get_addressed_line_node(from - 1);
1214 					/* this get_addressed_line_node last! */
1215 	if (isglobal)
1216 		unset_active_nodes(p->q_forw, n);
1217 	REQUE(p, n);
1218 	addr_last -= to - from + 1;
1219 	current_addr = from - 1;
1220 	modified = 1;
1221 	SPL0();
1222 	return 0;
1223 }
1224 
1225 
1226 /* display_lines: print a range of lines to stdout */
1227 int
1228 display_lines(long from, long to, int gflag)
1229 {
1230 	line_t *bp;
1231 	line_t *ep;
1232 	char *s;
1233 
1234 	if (!from) {
1235 		errmsg = "invalid address";
1236 		return ERR;
1237 	}
1238 	ep = get_addressed_line_node(INC_MOD(to, addr_last));
1239 	bp = get_addressed_line_node(from);
1240 	for (; bp != ep; bp = bp->q_forw) {
1241 		if ((s = get_sbuf_line(bp)) == NULL)
1242 			return ERR;
1243 		if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1244 			return ERR;
1245 	}
1246 	return 0;
1247 }
1248 
1249 
1250 #define MAXMARK 26			/* max number of marks */
1251 
1252 line_t	*mark[MAXMARK];			/* line markers */
1253 int markno;				/* line marker count */
1254 
1255 /* mark_line_node: set a line node mark */
1256 int
1257 mark_line_node(line_t *lp, int n)
1258 {
1259 	if (!islower((unsigned char)n)) {
1260 		errmsg = "invalid mark character";
1261 		return ERR;
1262 	} else if (mark[n - 'a'] == NULL)
1263 		markno++;
1264 	mark[n - 'a'] = lp;
1265 	return 0;
1266 }
1267 
1268 
1269 /* get_marked_node_addr: return address of a marked line */
1270 long
1271 get_marked_node_addr(int n)
1272 {
1273 	if (!islower((unsigned char)n)) {
1274 		errmsg = "invalid mark character";
1275 		return ERR;
1276 	}
1277 	return get_line_node_addr(mark[n - 'a']);
1278 }
1279 
1280 
1281 /* unmark_line_node: clear line node mark */
1282 void
1283 unmark_line_node(line_t *lp)
1284 {
1285 	int i;
1286 
1287 	for (i = 0; markno && i < MAXMARK; i++)
1288 		if (mark[i] == lp) {
1289 			mark[i] = NULL;
1290 			markno--;
1291 		}
1292 }
1293 
1294 
1295 /* dup_line_node: return a pointer to a copy of a line node */
1296 line_t *
1297 dup_line_node(line_t *lp)
1298 {
1299 	line_t *np;
1300 
1301 	if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1302 		fprintf(stderr, "%s\n", strerror(errno));
1303 		errmsg = "out of memory";
1304 		return NULL;
1305 	}
1306 	np->seek = lp->seek;
1307 	np->len = lp->len;
1308 	return np;
1309 }
1310 
1311 
1312 /* has_trailing_escape:  return the parity of escapes preceding a character
1313    in a string */
1314 int
1315 has_trailing_escape(char *s, char *t)
1316 {
1317     return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1318 }
1319 
1320 
1321 /* strip_escapes: return copy of escaped string of at most length PATH_MAX */
1322 char *
1323 strip_escapes(char *s)
1324 {
1325 	static char *file = NULL;
1326 	static int filesz = 0;
1327 
1328 	int i = 0;
1329 
1330 	REALLOC(file, filesz, PATH_MAX, NULL);
1331 	while (i < filesz - 1	/* Worry about a possible trailing escape */
1332 	       && (file[i++] = (*s == '\\') ? *++s : *s))
1333 		s++;
1334 	return file;
1335 }
1336 
1337 
1338 void
1339 signal_hup(int signo)
1340 {
1341 	if (mutex)
1342 		sigflags |= (1 << (signo - 1));
1343 	else
1344 		handle_hup(signo);
1345 }
1346 
1347 
1348 void
1349 signal_int(int signo)
1350 {
1351 	if (mutex)
1352 		sigflags |= (1 << (signo - 1));
1353 	else
1354 		handle_int(signo);
1355 }
1356 
1357 
1358 void
1359 handle_hup(int signo)
1360 {
1361 	char *hup = NULL;		/* hup filename */
1362 	char *s;
1363 	char ed_hup[] = "ed.hup";
1364 	int n;
1365 
1366 	if (!sigactive)
1367 		quit(1);
1368 	sigflags &= ~(1 << (signo - 1));
1369 	if (addr_last && write_file(ed_hup, "w", 1, addr_last) < 0 &&
1370 	    (s = getenv("HOME")) != NULL &&
1371 	    (n = strlen(s)) + 8 <= PATH_MAX &&	/* "ed.hup" + '/' */
1372 	    (hup = (char *) malloc(n + 10)) != NULL) {
1373 		strcpy(hup, s);
1374 		if (hup[n - 1] != '/')
1375 			hup[n] = '/', hup[n+1] = '\0';
1376 		strcat(hup, "ed.hup");
1377 		write_file(hup, "w", 1, addr_last);
1378 	}
1379 	quit(2);
1380 }
1381 
1382 
1383 void
1384 handle_int(int signo)
1385 {
1386 	if (!sigactive)
1387 		quit(1);
1388 	sigflags &= ~(1 << (signo - 1));
1389 #ifdef _POSIX_SOURCE
1390 	siglongjmp(env, -1);
1391 #else
1392 	longjmp(env, -1);
1393 #endif
1394 }
1395 
1396 
1397 int cols = 72;				/* wrap column */
1398 
1399 void
1400 handle_winch(int signo)
1401 {
1402 	int save_errno = errno;
1403 
1404 	struct winsize ws;		/* window size structure */
1405 
1406 	sigflags &= ~(1 << (signo - 1));
1407 	if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1408 		if (ws.ws_row > 2) rows = ws.ws_row - 2;
1409 		if (ws.ws_col > 8) cols = ws.ws_col - 8;
1410 	}
1411 	errno = save_errno;
1412 }
1413 
1414 
1415 /* is_legal_filename: return a legal filename */
1416 int
1417 is_legal_filename(char *s)
1418 {
1419 	if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1420 		errmsg = "shell access restricted";
1421 		return 0;
1422 	}
1423 	return 1;
1424 }
1425