xref: /src/bin/ed/main.c (revision 9eeab27c56db507f88c3334172e62357c092707e)
1 /* main.c: This file contains the main control and user-interface routines
2    for the ed line editor. */
3 /*-
4  * SPDX-License-Identifier: BSD-2-Clause
5  *
6  * Copyright (c) 1993 Andrew Moore, Talke Studio.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 /*
32  * CREDITS
33  *
34  *	This program is based on the editor algorithm described in
35  *	Brian W. Kernighan and P. J. Plauger's book "Software Tools
36  *	in Pascal," Addison-Wesley, 1981.
37  *
38  *	The buffering algorithm is attributed to Rodney Ruddock of
39  *	the University of Guelph, Guelph, Ontario.
40  *
41  */
42 
43 #include <sys/types.h>
44 
45 #include <sys/ioctl.h>
46 #include <sys/wait.h>
47 #include <ctype.h>
48 #include <locale.h>
49 #include <pwd.h>
50 #include <setjmp.h>
51 
52 #include "ed.h"
53 
54 
55 #ifdef _POSIX_SOURCE
56 static sigjmp_buf env;
57 #else
58 static jmp_buf env;
59 #endif
60 
61 /* static buffers */
62 char stdinbuf[1];		/* stdin buffer */
63 static char *shcmd;		/* shell command buffer */
64 static int shcmdsz;		/* shell command buffer size */
65 static int shcmdi;		/* shell command buffer index */
66 char *ibuf;			/* ed command-line buffer */
67 int ibufsz;			/* ed command-line buffer size */
68 char *ibufp;			/* pointer to ed command-line buffer */
69 
70 /* global flags */
71 static int garrulous = 0;	/* if set, print all error messages */
72 int isbinary;			/* if set, buffer contains ASCII NULs */
73 int isglobal;			/* if set, doing a global command */
74 int modified;			/* if set, buffer modified since last write */
75 int mutex = 0;			/* if set, signals set "sigflags" */
76 static int red = 0;		/* if set, restrict shell/directory access */
77 int scripted = 0;		/* if set, suppress diagnostics */
78 int sigflags = 0;		/* if set, signals received while mutex set */
79 static int sigactive = 0;	/* if set, signal handlers are enabled */
80 
81 static char old_filename[PATH_MAX] = ""; /* default filename */
82 long current_addr;		/* current address in editor buffer */
83 long addr_last;			/* last address in editor buffer */
84 int lineno;			/* script line number */
85 static const char *prompt;	/* command-line prompt */
86 static const char *dps = "*";	/* default command-line prompt */
87 
88 static const char *usage = "usage: %s [-] [-sx] [-p string] [file]\n";
89 
90 /* ed: line editor */
91 int
main(volatile int argc,char ** volatile argv)92 main(volatile int argc, char ** volatile argv)
93 {
94 	int c, n;
95 	long status = 0;
96 
97 	(void)setlocale(LC_ALL, "");
98 
99 	red = (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
100 top:
101 	while ((c = getopt(argc, argv, "p:sx")) != -1)
102 		switch(c) {
103 		case 'p':				/* set prompt */
104 			prompt = optarg;
105 			break;
106 		case 's':				/* run script */
107 			scripted = 1;
108 			break;
109 		case 'x':				/* use crypt */
110 			fprintf(stderr, "crypt unavailable\n?\n");
111 			break;
112 
113 		default:
114 			fprintf(stderr, usage, red ? "red" : "ed");
115 			exit(1);
116 		}
117 	argv += optind;
118 	argc -= optind;
119 	if (argc && **argv == '-') {
120 		scripted = 1;
121 		if (argc > 1) {
122 			optind = 1;
123 			goto top;
124 		}
125 		argv++;
126 		argc--;
127 	}
128 	/* assert: reliable signals! */
129 #ifdef SIGWINCH
130 	handle_winch(SIGWINCH);
131 	if (isatty(0)) signal(SIGWINCH, handle_winch);
132 #endif
133 	signal(SIGHUP, signal_hup);
134 	signal(SIGQUIT, SIG_IGN);
135 	signal(SIGINT, signal_int);
136 #ifdef _POSIX_SOURCE
137 	if ((status = sigsetjmp(env, 1)))
138 #else
139 	if ((status = setjmp(env)))
140 #endif
141 	{
142 		fputs("\n?\n", stderr);
143 		errmsg = "interrupt";
144 	} else {
145 		init_buffers();
146 		sigactive = 1;			/* enable signal handlers */
147 		if (argc && **argv && is_legal_filename(*argv)) {
148 			if (read_file(*argv, 0) < 0 && !isatty(0))
149 				quit(2);
150 			else if (**argv != '!')
151 				if (strlcpy(old_filename, *argv, sizeof(old_filename))
152 				    >= sizeof(old_filename))
153 					quit(2);
154 		} else if (argc) {
155 			fputs("?\n", stderr);
156 			if (**argv == '\0')
157 				errmsg = "invalid filename";
158 			if (!isatty(0))
159 				quit(2);
160 		}
161 	}
162 	for (;;) {
163 		if (status < 0 && garrulous)
164 			fprintf(stderr, "%s\n", errmsg);
165 		if (prompt) {
166 			printf("%s", prompt);
167 			fflush(stdout);
168 		}
169 		if ((n = get_tty_line()) < 0) {
170 			status = ERR;
171 			continue;
172 		} else if (n == 0) {
173 			if (modified && !scripted) {
174 				fputs("?\n", stderr);
175 				errmsg = "warning: file modified";
176 				if (!isatty(0)) {
177 					if (garrulous)
178 						fprintf(stderr,
179 						    "script, line %d: %s\n",
180 						    lineno, errmsg);
181 					quit(2);
182 				}
183 				clearerr(stdin);
184 				modified = 0;
185 				status = EMOD;
186 				continue;
187 			} else
188 				quit(0);
189 		} else if (ibuf[n - 1] != '\n') {
190 			/* discard line */
191 			errmsg = "unexpected end-of-file";
192 			clearerr(stdin);
193 			status = ERR;
194 			continue;
195 		}
196 		isglobal = 0;
197 		if ((status = extract_addr_range()) >= 0 &&
198 		    (status = exec_command()) >= 0)
199 			if (!status ||
200 			    (status = display_lines(current_addr, current_addr,
201 			        status)) >= 0)
202 				continue;
203 		switch (status) {
204 		case EOF:
205 			quit(0);
206 		case EMOD:
207 			modified = 0;
208 			fputs("?\n", stderr);		/* give warning */
209 			errmsg = "warning: file modified";
210 			if (!isatty(0)) {
211 				if (garrulous)
212 					fprintf(stderr, "script, line %d: %s\n",
213 					    lineno, errmsg);
214 				quit(2);
215 			}
216 			break;
217 		case FATAL:
218 			if (!isatty(0)) {
219 				if (garrulous)
220 					fprintf(stderr, "script, line %d: %s\n",
221 					    lineno, errmsg);
222 			} else if (garrulous)
223 				fprintf(stderr, "%s\n", errmsg);
224 			quit(3);
225 		default:
226 			fputs("?\n", stderr);
227 			if (!isatty(0)) {
228 				if (garrulous)
229 					fprintf(stderr, "script, line %d: %s\n",
230 					    lineno, errmsg);
231 				quit(2);
232 			}
233 			break;
234 		}
235 	}
236 	/*NOTREACHED*/
237 }
238 
239 long first_addr, second_addr;
240 static long addr_cnt;
241 
242 /* extract_addr_range: get line addresses from the command buffer until an
243    illegal address is seen; return status */
244 int
extract_addr_range(void)245 extract_addr_range(void)
246 {
247 	long addr;
248 
249 	addr_cnt = 0;
250 	first_addr = second_addr = current_addr;
251 	while ((addr = next_addr()) >= 0) {
252 		addr_cnt++;
253 		first_addr = second_addr;
254 		second_addr = addr;
255 		if (*ibufp != ',' && *ibufp != ';')
256 			break;
257 		else if (*ibufp++ == ';')
258 			current_addr = addr;
259 	}
260 	if ((addr_cnt = min(addr_cnt, 2)) == 1 || second_addr != addr)
261 		first_addr = second_addr;
262 	return (addr == ERR) ? ERR : 0;
263 }
264 
265 
266 #define SKIP_BLANKS() while (isspace((unsigned char)*ibufp) && *ibufp != '\n') ibufp++
267 
268 #define MUST_BE_FIRST() do {					\
269 	if (!first) {						\
270 		errmsg = "invalid address";			\
271 		return ERR;					\
272 	}							\
273 } while (0)
274 
275 /*  next_addr: return the next line address in the command buffer */
276 long
next_addr(void)277 next_addr(void)
278 {
279 	const char *hd;
280 	long addr = current_addr;
281 	long n;
282 	int first = 1;
283 	int c;
284 
285 	SKIP_BLANKS();
286 	for (hd = ibufp;; first = 0)
287 		switch (c = *ibufp) {
288 		case '+':
289 		case '\t':
290 		case ' ':
291 		case '-':
292 		case '^':
293 			ibufp++;
294 			SKIP_BLANKS();
295 			if (isdigit((unsigned char)*ibufp)) {
296 				STRTOL(n, ibufp);
297 				addr += (c == '-' || c == '^') ? -n : n;
298 			} else if (!isspace((unsigned char)c))
299 				addr += (c == '-' || c == '^') ? -1 : 1;
300 			break;
301 		case '0': case '1': case '2':
302 		case '3': case '4': case '5':
303 		case '6': case '7': case '8': case '9':
304 			MUST_BE_FIRST();
305 			STRTOL(addr, ibufp);
306 			break;
307 		case '.':
308 		case '$':
309 			MUST_BE_FIRST();
310 			ibufp++;
311 			addr = (c == '.') ? current_addr : addr_last;
312 			break;
313 		case '/':
314 		case '?':
315 			MUST_BE_FIRST();
316 			if ((addr = get_matching_node_addr(
317 			    get_compiled_pattern(), c == '/')) < 0)
318 				return ERR;
319 			else if (c == *ibufp)
320 				ibufp++;
321 			break;
322 		case '\'':
323 			MUST_BE_FIRST();
324 			ibufp++;
325 			if ((addr = get_marked_node_addr(*ibufp++)) < 0)
326 				return ERR;
327 			break;
328 		case '%':
329 		case ',':
330 		case ';':
331 			if (first) {
332 				ibufp++;
333 				addr_cnt++;
334 				second_addr = (c == ';') ? current_addr : 1;
335 				if ((addr = next_addr()) < 0)
336 					addr = addr_last;
337 				break;
338 			}
339 			/* FALLTHROUGH */
340 		default:
341 			if (ibufp == hd)
342 				return EOF;
343 			else if (addr < 0 || addr_last < addr) {
344 				errmsg = "invalid address";
345 				return ERR;
346 			} else
347 				return addr;
348 		}
349 	/* NOTREACHED */
350 }
351 
352 
353 #ifdef BACKWARDS
354 /* GET_THIRD_ADDR: get a legal address from the command buffer */
355 #define GET_THIRD_ADDR(addr) \
356 { \
357 	long ol1, ol2; \
358 \
359 	ol1 = first_addr, ol2 = second_addr; \
360 	if (extract_addr_range() < 0) \
361 		return ERR; \
362 	else if (addr_cnt == 0) { \
363 		errmsg = "destination expected"; \
364 		return ERR; \
365 	} else if (second_addr < 0 || addr_last < second_addr) { \
366 		errmsg = "invalid address"; \
367 		return ERR; \
368 	} \
369 	addr = second_addr; \
370 	first_addr = ol1, second_addr = ol2; \
371 }
372 #else	/* BACKWARDS */
373 /* GET_THIRD_ADDR: get a legal address from the command buffer */
374 #define GET_THIRD_ADDR(addr) \
375 { \
376 	long ol1, ol2; \
377 \
378 	ol1 = first_addr, ol2 = second_addr; \
379 	if (extract_addr_range() < 0) \
380 		return ERR; \
381 	if (second_addr < 0 || addr_last < second_addr) { \
382 		errmsg = "invalid address"; \
383 		return ERR; \
384 	} \
385 	addr = second_addr; \
386 	first_addr = ol1, second_addr = ol2; \
387 }
388 #endif
389 
390 
391 /* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
392 #define GET_COMMAND_SUFFIX() { \
393 	int done = 0; \
394 	do { \
395 		switch(*ibufp) { \
396 		case 'p': \
397 			gflag |= GPR, ibufp++; \
398 			break; \
399 		case 'l': \
400 			gflag |= GLS, ibufp++; \
401 			break; \
402 		case 'n': \
403 			gflag |= GNP, ibufp++; \
404 			break; \
405 		default: \
406 			done++; \
407 		} \
408 	} while (!done); \
409 	if (*ibufp++ != '\n') { \
410 		errmsg = "invalid command suffix"; \
411 		return ERR; \
412 	} \
413 }
414 
415 
416 /* sflags */
417 #define SGG 001		/* complement previous global substitute suffix */
418 #define SGP 002		/* complement previous print suffix */
419 #define SGR 004		/* use last regex instead of last pat */
420 #define SGF 010		/* repeat last substitution */
421 
422 int patlock = 0;	/* if set, pattern not freed by get_compiled_pattern() */
423 
424 long rows = 22;		/* scroll length: ws_row - 2 */
425 
426 /* exec_command: execute the next command in command buffer; return print
427    request, if any */
428 int
exec_command(void)429 exec_command(void)
430 {
431 	static pattern_t *pat = NULL;
432 	static int sgflag = 0;
433 	static long sgnum = 0;
434 
435 	pattern_t *tpat;
436 	char *fnp;
437 	int gflag = 0;
438 	int sflags = 0;
439 	long addr = 0;
440 	int n = 0;
441 	int c;
442 
443 	SKIP_BLANKS();
444 	switch(c = *ibufp++) {
445 	case 'a':
446 		GET_COMMAND_SUFFIX();
447 		if (!isglobal) clear_undo_stack();
448 		if (append_lines(second_addr) < 0)
449 			return ERR;
450 		break;
451 	case 'c':
452 		if (check_addr_range(current_addr, current_addr) < 0)
453 			return ERR;
454 		GET_COMMAND_SUFFIX();
455 		if (!isglobal) clear_undo_stack();
456 		if (delete_lines(first_addr, second_addr) < 0 ||
457 		    append_lines(current_addr) < 0)
458 			return ERR;
459 		break;
460 	case 'd':
461 		if (check_addr_range(current_addr, current_addr) < 0)
462 			return ERR;
463 		GET_COMMAND_SUFFIX();
464 		if (!isglobal) clear_undo_stack();
465 		if (delete_lines(first_addr, second_addr) < 0)
466 			return ERR;
467 		else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
468 			current_addr = addr;
469 		break;
470 	case 'e':
471 		if (modified && !scripted)
472 			return EMOD;
473 		/* FALLTHROUGH */
474 	case 'E':
475 		if (addr_cnt > 0) {
476 			errmsg = "unexpected address";
477 			return ERR;
478 		} else if (!isspace((unsigned char)*ibufp)) {
479 			errmsg = "unexpected command suffix";
480 			return ERR;
481 		} else if ((fnp = get_filename()) == NULL)
482 			return ERR;
483 		GET_COMMAND_SUFFIX();
484 		if (delete_lines(1, addr_last) < 0)
485 			return ERR;
486 		clear_undo_stack();
487 		if (close_sbuf() < 0)
488 			return ERR;
489 		else if (open_sbuf() < 0)
490 			return FATAL;
491 		if (*fnp && *fnp != '!')
492 			 strlcpy(old_filename, fnp, PATH_MAX);
493 #ifdef BACKWARDS
494 		if (*fnp == '\0' && *old_filename == '\0') {
495 			errmsg = "no current filename";
496 			return ERR;
497 		}
498 #endif
499 		if (read_file(*fnp ? fnp : old_filename, 0) < 0)
500 			return ERR;
501 		clear_undo_stack();
502 		modified = 0;
503 		u_current_addr = u_addr_last = -1;
504 		break;
505 	case 'f':
506 		if (addr_cnt > 0) {
507 			errmsg = "unexpected address";
508 			return ERR;
509 		} else if (!isspace((unsigned char)*ibufp)) {
510 			errmsg = "unexpected command suffix";
511 			return ERR;
512 		} else if ((fnp = get_filename()) == NULL)
513 			return ERR;
514 		else if (*fnp == '!') {
515 			errmsg = "invalid redirection";
516 			return ERR;
517 		}
518 		GET_COMMAND_SUFFIX();
519 		if (*fnp)
520 			strlcpy(old_filename, fnp, PATH_MAX);
521 		printf("%s\n", strip_escapes(old_filename));
522 		break;
523 	case 'g':
524 	case 'v':
525 	case 'G':
526 	case 'V':
527 		if (isglobal) {
528 			errmsg = "cannot nest global commands";
529 			return ERR;
530 		} else if (check_addr_range(1, addr_last) < 0)
531 			return ERR;
532 		else if (build_active_list(c == 'g' || c == 'G') < 0)
533 			return ERR;
534 		else if ((n = (c == 'G' || c == 'V')))
535 			GET_COMMAND_SUFFIX();
536 		isglobal++;
537 		if (exec_global(n, gflag) < 0)
538 			return ERR;
539 		break;
540 	case 'h':
541 		if (addr_cnt > 0) {
542 			errmsg = "unexpected address";
543 			return ERR;
544 		}
545 		GET_COMMAND_SUFFIX();
546 		if (*errmsg) fprintf(stderr, "%s\n", errmsg);
547 		break;
548 	case 'H':
549 		if (addr_cnt > 0) {
550 			errmsg = "unexpected address";
551 			return ERR;
552 		}
553 		GET_COMMAND_SUFFIX();
554 		if ((garrulous = 1 - garrulous) && *errmsg)
555 			fprintf(stderr, "%s\n", errmsg);
556 		break;
557 	case 'i':
558 		if (second_addr == 0) {
559 			errmsg = "invalid address";
560 			return ERR;
561 		}
562 		GET_COMMAND_SUFFIX();
563 		if (!isglobal) clear_undo_stack();
564 		if (append_lines(second_addr - 1) < 0)
565 			return ERR;
566 		break;
567 	case 'j':
568 		if (check_addr_range(current_addr, current_addr + 1) < 0)
569 			return ERR;
570 		GET_COMMAND_SUFFIX();
571 		if (!isglobal) clear_undo_stack();
572 		if (first_addr != second_addr &&
573 		    join_lines(first_addr, second_addr) < 0)
574 			return ERR;
575 		break;
576 	case 'k':
577 		c = *ibufp++;
578 		if (second_addr == 0) {
579 			errmsg = "invalid address";
580 			return ERR;
581 		}
582 		GET_COMMAND_SUFFIX();
583 		if (mark_line_node(get_addressed_line_node(second_addr), c) < 0)
584 			return ERR;
585 		break;
586 	case 'l':
587 		if (check_addr_range(current_addr, current_addr) < 0)
588 			return ERR;
589 		GET_COMMAND_SUFFIX();
590 		if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
591 			return ERR;
592 		gflag = 0;
593 		break;
594 	case 'm':
595 		if (check_addr_range(current_addr, current_addr) < 0)
596 			return ERR;
597 		GET_THIRD_ADDR(addr);
598 		if (first_addr <= addr && addr < second_addr) {
599 			errmsg = "invalid destination";
600 			return ERR;
601 		}
602 		GET_COMMAND_SUFFIX();
603 		if (!isglobal) clear_undo_stack();
604 		if (move_lines(addr) < 0)
605 			return ERR;
606 		break;
607 	case 'n':
608 		if (check_addr_range(current_addr, current_addr) < 0)
609 			return ERR;
610 		GET_COMMAND_SUFFIX();
611 		if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
612 			return ERR;
613 		gflag = 0;
614 		break;
615 	case 'p':
616 		if (check_addr_range(current_addr, current_addr) < 0)
617 			return ERR;
618 		GET_COMMAND_SUFFIX();
619 		if (display_lines(first_addr, second_addr, gflag | GPR) < 0)
620 			return ERR;
621 		gflag = 0;
622 		break;
623 	case 'P':
624 		if (addr_cnt > 0) {
625 			errmsg = "unexpected address";
626 			return ERR;
627 		}
628 		GET_COMMAND_SUFFIX();
629 		prompt = prompt ? NULL : optarg ? optarg : dps;
630 		break;
631 	case 'q':
632 	case 'Q':
633 		if (addr_cnt > 0) {
634 			errmsg = "unexpected address";
635 			return ERR;
636 		}
637 		GET_COMMAND_SUFFIX();
638 		gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
639 		break;
640 	case 'r':
641 		if (!isspace((unsigned char)*ibufp)) {
642 			errmsg = "unexpected command suffix";
643 			return ERR;
644 		} else if (addr_cnt == 0)
645 			second_addr = addr_last;
646 		if ((fnp = get_filename()) == NULL)
647 			return ERR;
648 		GET_COMMAND_SUFFIX();
649 		if (!isglobal) clear_undo_stack();
650 		if (*old_filename == '\0' && *fnp != '!')
651 			strlcpy(old_filename, fnp, PATH_MAX);
652 #ifdef BACKWARDS
653 		if (*fnp == '\0' && *old_filename == '\0') {
654 			errmsg = "no current filename";
655 			return ERR;
656 		}
657 #endif
658 		if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
659 			return ERR;
660 		else if (addr && addr != addr_last)
661 			modified = 1;
662 		break;
663 	case 's':
664 		do {
665 			switch(*ibufp) {
666 			case '\n':
667 				sflags |=SGF;
668 				break;
669 			case 'g':
670 				sflags |= SGG;
671 				ibufp++;
672 				break;
673 			case 'p':
674 				sflags |= SGP;
675 				ibufp++;
676 				break;
677 			case 'r':
678 				sflags |= SGR;
679 				ibufp++;
680 				break;
681 			case '0': case '1': case '2': case '3': case '4':
682 			case '5': case '6': case '7': case '8': case '9':
683 				STRTOL(sgnum, ibufp);
684 				sflags |= SGF;
685 				sgflag &= ~GSG;		/* override GSG */
686 				break;
687 			default:
688 				if (sflags) {
689 					errmsg = "invalid command suffix";
690 					return ERR;
691 				}
692 			}
693 		} while (sflags && *ibufp != '\n');
694 		if (sflags && !pat) {
695 			errmsg = "no previous substitution";
696 			return ERR;
697 		} else if (sflags & SGG)
698 			sgnum = 0;		/* override numeric arg */
699 		if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
700 			errmsg = "invalid pattern delimiter";
701 			return ERR;
702 		}
703 		tpat = pat;
704 		SPL1();
705 		if ((!sflags || (sflags & SGR)) &&
706 		    (tpat = get_compiled_pattern()) == NULL) {
707 		 	SPL0();
708 			return ERR;
709 		} else if (tpat != pat) {
710 			if (pat) {
711 				regfree(pat);
712 				free(pat);
713 			}
714 			pat = tpat;
715 			patlock = 1;		/* reserve pattern */
716 		}
717 		SPL0();
718 		if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
719 			return ERR;
720 		else if (isglobal)
721 			sgflag |= GLB;
722 		else
723 			sgflag &= ~GLB;
724 		if (sflags & SGG)
725 			sgflag ^= GSG;
726 		if (sflags & SGP)
727 			sgflag ^= GPR, sgflag &= ~(GLS | GNP);
728 		do {
729 			switch(*ibufp) {
730 			case 'p':
731 				sgflag |= GPR, ibufp++;
732 				break;
733 			case 'l':
734 				sgflag |= GLS, ibufp++;
735 				break;
736 			case 'n':
737 				sgflag |= GNP, ibufp++;
738 				break;
739 			default:
740 				n++;
741 			}
742 		} while (!n);
743 		if (check_addr_range(current_addr, current_addr) < 0)
744 			return ERR;
745 		GET_COMMAND_SUFFIX();
746 		if (!isglobal) clear_undo_stack();
747 		if (search_and_replace(pat, sgflag, sgnum) < 0)
748 			return ERR;
749 		break;
750 	case 't':
751 		if (check_addr_range(current_addr, current_addr) < 0)
752 			return ERR;
753 		GET_THIRD_ADDR(addr);
754 		GET_COMMAND_SUFFIX();
755 		if (!isglobal) clear_undo_stack();
756 		if (copy_lines(addr) < 0)
757 			return ERR;
758 		break;
759 	case 'u':
760 		if (addr_cnt > 0) {
761 			errmsg = "unexpected address";
762 			return ERR;
763 		}
764 		GET_COMMAND_SUFFIX();
765 		if (pop_undo_stack() < 0)
766 			return ERR;
767 		break;
768 	case 'w':
769 	case 'W':
770 		if ((n = *ibufp) == 'q' || n == 'Q') {
771 			gflag = EOF;
772 			ibufp++;
773 		}
774 		if (!isspace((unsigned char)*ibufp)) {
775 			errmsg = "unexpected command suffix";
776 			return ERR;
777 		} else if ((fnp = get_filename()) == NULL)
778 			return ERR;
779 		if (addr_cnt == 0 && !addr_last)
780 			first_addr = second_addr = 0;
781 		else if (check_addr_range(1, addr_last) < 0)
782 			return ERR;
783 		GET_COMMAND_SUFFIX();
784 		if (*old_filename == '\0' && *fnp != '!')
785 			strlcpy(old_filename, fnp, PATH_MAX);
786 #ifdef BACKWARDS
787 		if (*fnp == '\0' && *old_filename == '\0') {
788 			errmsg = "no current filename";
789 			return ERR;
790 		}
791 #endif
792 		if ((addr = write_file(*fnp ? fnp : old_filename,
793 		    (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
794 			return ERR;
795 		else if (addr == addr_last && *fnp != '!')
796 			modified = 0;
797 		else if (modified && !scripted && n == 'q')
798 			gflag = EMOD;
799 		break;
800 	case 'x':
801 		if (addr_cnt > 0) {
802 			errmsg = "unexpected address";
803 			return ERR;
804 		}
805 		GET_COMMAND_SUFFIX();
806 		errmsg = "crypt unavailable";
807 		return ERR;
808 	case 'z':
809 #ifdef BACKWARDS
810 		if (check_addr_range(first_addr = 1, current_addr + 1) < 0)
811 #else
812 		if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0)
813 #endif
814 			return ERR;
815 		else if ('0' < *ibufp && *ibufp <= '9')
816 			STRTOL(rows, ibufp);
817 		GET_COMMAND_SUFFIX();
818 		if (display_lines(second_addr, min(addr_last,
819 		    second_addr + rows), gflag) < 0)
820 			return ERR;
821 		gflag = 0;
822 		break;
823 	case '=':
824 		GET_COMMAND_SUFFIX();
825 		printf("%ld\n", addr_cnt ? second_addr : addr_last);
826 		break;
827 	case '!':
828 		if (addr_cnt > 0) {
829 			errmsg = "unexpected address";
830 			return ERR;
831 		} else if ((sflags = get_shell_command()) < 0)
832 			return ERR;
833 		GET_COMMAND_SUFFIX();
834 		if (sflags) printf("%s\n", shcmd + 1);
835 		system(shcmd + 1);
836 		if (!scripted) printf("!\n");
837 		break;
838 	case '\n':
839 #ifdef BACKWARDS
840 		if (check_addr_range(first_addr = 1, current_addr + 1) < 0
841 #else
842 		if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0
843 #endif
844 		 || display_lines(second_addr, second_addr, 0) < 0)
845 			return ERR;
846 		break;
847 	default:
848 		errmsg = "unknown command";
849 		return ERR;
850 	}
851 	return gflag;
852 }
853 
854 
855 /* check_addr_range: return status of address range check */
856 int
check_addr_range(long n,long m)857 check_addr_range(long n, long m)
858 {
859 	if (addr_cnt == 0) {
860 		first_addr = n;
861 		second_addr = m;
862 	}
863 	if (first_addr > second_addr || 1 > first_addr ||
864 	    second_addr > addr_last) {
865 		errmsg = "invalid address";
866 		return ERR;
867 	}
868 	return 0;
869 }
870 
871 
872 /* get_matching_node_addr: return the address of the next line matching a
873    pattern in a given direction.  wrap around begin/end of editor buffer if
874    necessary */
875 long
get_matching_node_addr(pattern_t * pat,int dir)876 get_matching_node_addr(pattern_t *pat, int dir)
877 {
878 	char *s;
879 	long n = current_addr;
880 	line_t *lp;
881 
882 	if (!pat) return ERR;
883 	do {
884 	       if ((n = dir ? INC_MOD(n, addr_last) : DEC_MOD(n, addr_last))) {
885 			lp = get_addressed_line_node(n);
886 			if ((s = get_sbuf_line(lp)) == NULL)
887 				return ERR;
888 			if (isbinary)
889 				NUL_TO_NEWLINE(s, lp->len);
890 			if (!regexec(pat, s, 0, NULL, 0))
891 				return n;
892 	       }
893 	} while (n != current_addr);
894 	errmsg = "no match";
895 	return  ERR;
896 }
897 
898 
899 /* get_filename: return pointer to copy of filename in the command buffer */
900 char *
get_filename(void)901 get_filename(void)
902 {
903 	static char *file = NULL;
904 	static int filesz = 0;
905 
906 	int n;
907 
908 	if (*ibufp != '\n') {
909 		SKIP_BLANKS();
910 		if (*ibufp == '\n') {
911 			errmsg = "invalid filename";
912 			return NULL;
913 		} else if ((ibufp = get_extended_line(&n, 1)) == NULL)
914 			return NULL;
915 		else if (*ibufp == '!') {
916 			ibufp++;
917 			if ((n = get_shell_command()) < 0)
918 				return NULL;
919 			if (n)
920 				printf("%s\n", shcmd + 1);
921 			return shcmd;
922 		} else if (n > PATH_MAX - 1) {
923 			errmsg = "filename too long";
924 			return  NULL;
925 		}
926 	}
927 #ifndef BACKWARDS
928 	else if (*old_filename == '\0') {
929 		errmsg = "no current filename";
930 		return  NULL;
931 	}
932 #endif
933 	REALLOC(file, filesz, PATH_MAX, NULL);
934 	for (n = 0; *ibufp != '\n';)
935 		file[n++] = *ibufp++;
936 	file[n] = '\0';
937 	return is_legal_filename(file) ? file : NULL;
938 }
939 
940 
941 /* get_shell_command: read a shell command from stdin; return substitution
942    status */
943 int
get_shell_command(void)944 get_shell_command(void)
945 {
946 	static char *buf = NULL;
947 	static int n = 0;
948 
949 	char *s;			/* substitution char pointer */
950 	int i = 0;
951 	int j = 0;
952 
953 	if (red) {
954 		errmsg = "shell access restricted";
955 		return ERR;
956 	} else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
957 		return ERR;
958 	REALLOC(buf, n, j + 1, ERR);
959 	buf[i++] = '!';			/* prefix command w/ bang */
960 	while (*ibufp != '\n')
961 		switch (*ibufp) {
962 		default:
963 			REALLOC(buf, n, i + 2, ERR);
964 			buf[i++] = *ibufp;
965 			if (*ibufp++ == '\\')
966 				buf[i++] = *ibufp++;
967 			break;
968 		case '!':
969 			if (s != ibufp) {
970 				REALLOC(buf, n, i + 1, ERR);
971 				buf[i++] = *ibufp++;
972 			}
973 #ifdef BACKWARDS
974 			else if (shcmd == NULL || *(shcmd + 1) == '\0')
975 #else
976 			else if (shcmd == NULL)
977 #endif
978 			{
979 				errmsg = "no previous command";
980 				return ERR;
981 			} else {
982 				REALLOC(buf, n, i + shcmdi, ERR);
983 				for (s = shcmd + 1; s < shcmd + shcmdi;)
984 					buf[i++] = *s++;
985 				s = ibufp++;
986 			}
987 			break;
988 		case '%':
989 			if (*old_filename  == '\0') {
990 				errmsg = "no current filename";
991 				return ERR;
992 			}
993 			j = strlen(s = strip_escapes(old_filename));
994 			REALLOC(buf, n, i + j, ERR);
995 			while (j--)
996 				buf[i++] = *s++;
997 			s = ibufp++;
998 			break;
999 		}
1000 	REALLOC(shcmd, shcmdsz, i + 1, ERR);
1001 	memcpy(shcmd, buf, i);
1002 	shcmd[shcmdi = i] = '\0';
1003 	return *s == '!' || *s == '%';
1004 }
1005 
1006 
1007 /* append_lines: insert text from stdin to after line n; stop when either a
1008    single period is read or EOF; return status */
1009 int
append_lines(long n)1010 append_lines(long n)
1011 {
1012 	int l;
1013 	const char *lp = ibuf;
1014 	const char *eot;
1015 	undo_t *up = NULL;
1016 
1017 	for (current_addr = n;;) {
1018 		if (!isglobal) {
1019 			if ((l = get_tty_line()) < 0)
1020 				return ERR;
1021 			else if (l == 0 || ibuf[l - 1] != '\n') {
1022 				clearerr(stdin);
1023 				return  l ? EOF : 0;
1024 			}
1025 			lp = ibuf;
1026 		} else if (*(lp = ibufp) == '\0')
1027 			return 0;
1028 		else {
1029 			while (*ibufp++ != '\n')
1030 				;
1031 			l = ibufp - lp;
1032 		}
1033 		if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1034 			return 0;
1035 		}
1036 		eot = lp + l;
1037 		SPL1();
1038 		do {
1039 			if ((lp = put_sbuf_line(lp)) == NULL) {
1040 				SPL0();
1041 				return ERR;
1042 			} else if (up)
1043 				up->t = get_addressed_line_node(current_addr);
1044 			else if ((up = push_undo_stack(UADD, current_addr,
1045 			    current_addr)) == NULL) {
1046 				SPL0();
1047 				return ERR;
1048 			}
1049 		} while (lp != eot);
1050 		modified = 1;
1051 		SPL0();
1052 	}
1053 	/* NOTREACHED */
1054 }
1055 
1056 
1057 /* join_lines: replace a range of lines with the joined text of those lines */
1058 int
join_lines(long from,long to)1059 join_lines(long from, long to)
1060 {
1061 	static char *buf = NULL;
1062 	static int n;
1063 
1064 	char *s;
1065 	int size = 0;
1066 	line_t *bp, *ep;
1067 
1068 	ep = get_addressed_line_node(INC_MOD(to, addr_last));
1069 	bp = get_addressed_line_node(from);
1070 	for (; bp != ep; bp = bp->q_forw) {
1071 		if ((s = get_sbuf_line(bp)) == NULL)
1072 			return ERR;
1073 		REALLOC(buf, n, size + bp->len, ERR);
1074 		memcpy(buf + size, s, bp->len);
1075 		size += bp->len;
1076 	}
1077 	REALLOC(buf, n, size + 2, ERR);
1078 	memcpy(buf + size, "\n", 2);
1079 	if (delete_lines(from, to) < 0)
1080 		return ERR;
1081 	current_addr = from - 1;
1082 	SPL1();
1083 	if (put_sbuf_line(buf) == NULL ||
1084 	    push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1085 		SPL0();
1086 		return ERR;
1087 	}
1088 	modified = 1;
1089 	SPL0();
1090 	return 0;
1091 }
1092 
1093 
1094 /* move_lines: move a range of lines */
1095 int
move_lines(long addr)1096 move_lines(long addr)
1097 {
1098 	line_t *b1, *a1, *b2, *a2;
1099 	long n = INC_MOD(second_addr, addr_last);
1100 	long p = first_addr - 1;
1101 	int done = (addr == first_addr - 1 || addr == second_addr);
1102 
1103 	SPL1();
1104 	if (done) {
1105 		a2 = get_addressed_line_node(n);
1106 		b2 = get_addressed_line_node(p);
1107 		current_addr = second_addr;
1108 	} else if (push_undo_stack(UMOV, p, n) == NULL ||
1109 	    push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1110 		SPL0();
1111 		return ERR;
1112 	} else {
1113 		a1 = get_addressed_line_node(n);
1114 		if (addr < first_addr) {
1115 			b1 = get_addressed_line_node(p);
1116 			b2 = get_addressed_line_node(addr);
1117 					/* this get_addressed_line_node last! */
1118 		} else {
1119 			b2 = get_addressed_line_node(addr);
1120 			b1 = get_addressed_line_node(p);
1121 					/* this get_addressed_line_node last! */
1122 		}
1123 		a2 = b2->q_forw;
1124 		REQUE(b2, b1->q_forw);
1125 		REQUE(a1->q_back, a2);
1126 		REQUE(b1, a1);
1127 		current_addr = addr + ((addr < first_addr) ?
1128 		    second_addr - first_addr + 1 : 0);
1129 	}
1130 	if (isglobal)
1131 		unset_active_nodes(b2->q_forw, a2);
1132 	modified = 1;
1133 	SPL0();
1134 	return 0;
1135 }
1136 
1137 
1138 /* copy_lines: copy a range of lines; return status */
1139 int
copy_lines(long addr)1140 copy_lines(long addr)
1141 {
1142 	line_t *lp, *np = get_addressed_line_node(first_addr);
1143 	undo_t *up = NULL;
1144 	long n = second_addr - first_addr + 1;
1145 	long m = 0;
1146 
1147 	current_addr = addr;
1148 	if (first_addr <= addr && addr < second_addr) {
1149 		n =  addr - first_addr + 1;
1150 		m = second_addr - addr;
1151 	}
1152 	for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1153 		for (; n-- > 0; np = np->q_forw) {
1154 			SPL1();
1155 			if ((lp = dup_line_node(np)) == NULL) {
1156 				SPL0();
1157 				return ERR;
1158 			}
1159 			add_line_node(lp);
1160 			if (up)
1161 				up->t = lp;
1162 			else if ((up = push_undo_stack(UADD, current_addr,
1163 			    current_addr)) == NULL) {
1164 				SPL0();
1165 				return ERR;
1166 			}
1167 			modified = 1;
1168 			SPL0();
1169 		}
1170 	return 0;
1171 }
1172 
1173 
1174 /* delete_lines: delete a range of lines */
1175 int
delete_lines(long from,long to)1176 delete_lines(long from, long to)
1177 {
1178 	line_t *n, *p;
1179 
1180 	SPL1();
1181 	if (push_undo_stack(UDEL, from, to) == NULL) {
1182 		SPL0();
1183 		return ERR;
1184 	}
1185 	n = get_addressed_line_node(INC_MOD(to, addr_last));
1186 	p = get_addressed_line_node(from - 1);
1187 					/* this get_addressed_line_node last! */
1188 	if (isglobal)
1189 		unset_active_nodes(p->q_forw, n);
1190 	REQUE(p, n);
1191 	addr_last -= to - from + 1;
1192 	current_addr = from - 1;
1193 	modified = 1;
1194 	SPL0();
1195 	return 0;
1196 }
1197 
1198 
1199 /* display_lines: print a range of lines to stdout */
1200 int
display_lines(long from,long to,int gflag)1201 display_lines(long from, long to, int gflag)
1202 {
1203 	line_t *bp;
1204 	line_t *ep;
1205 	char *s;
1206 
1207 	if (!from) {
1208 		errmsg = "invalid address";
1209 		return ERR;
1210 	}
1211 	ep = get_addressed_line_node(INC_MOD(to, addr_last));
1212 	bp = get_addressed_line_node(from);
1213 	for (; bp != ep; bp = bp->q_forw) {
1214 		if ((s = get_sbuf_line(bp)) == NULL)
1215 			return ERR;
1216 		if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1217 			return ERR;
1218 	}
1219 	return 0;
1220 }
1221 
1222 
1223 #define MAXMARK 26			/* max number of marks */
1224 
1225 static line_t *mark[MAXMARK];		/* line markers */
1226 static int markno;			/* line marker count */
1227 
1228 /* mark_line_node: set a line node mark */
1229 int
mark_line_node(line_t * lp,int n)1230 mark_line_node(line_t *lp, int n)
1231 {
1232 	if (!islower((unsigned char)n)) {
1233 		errmsg = "invalid mark character";
1234 		return ERR;
1235 	} else if (mark[n - 'a'] == NULL)
1236 		markno++;
1237 	mark[n - 'a'] = lp;
1238 	return 0;
1239 }
1240 
1241 
1242 /* get_marked_node_addr: return address of a marked line */
1243 long
get_marked_node_addr(int n)1244 get_marked_node_addr(int n)
1245 {
1246 	if (!islower((unsigned char)n)) {
1247 		errmsg = "invalid mark character";
1248 		return ERR;
1249 	}
1250 	return get_line_node_addr(mark[n - 'a']);
1251 }
1252 
1253 
1254 /* unmark_line_node: clear line node mark */
1255 void
unmark_line_node(line_t * lp)1256 unmark_line_node(line_t *lp)
1257 {
1258 	int i;
1259 
1260 	for (i = 0; markno && i < MAXMARK; i++)
1261 		if (mark[i] == lp) {
1262 			mark[i] = NULL;
1263 			markno--;
1264 		}
1265 }
1266 
1267 
1268 /* dup_line_node: return a pointer to a copy of a line node */
1269 line_t *
dup_line_node(line_t * lp)1270 dup_line_node(line_t *lp)
1271 {
1272 	line_t *np;
1273 
1274 	if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1275 		fprintf(stderr, "%s\n", strerror(errno));
1276 		errmsg = "out of memory";
1277 		return NULL;
1278 	}
1279 	np->seek = lp->seek;
1280 	np->len = lp->len;
1281 	return np;
1282 }
1283 
1284 
1285 /* has_trailing_escape:  return the parity of escapes preceding a character
1286    in a string */
1287 int
has_trailing_escape(char * s,char * t)1288 has_trailing_escape(char *s, char *t)
1289 {
1290     return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1291 }
1292 
1293 
1294 /* strip_escapes: return a copy of escaped string of at most length PATH_MAX */
1295 char *
strip_escapes(char * s)1296 strip_escapes(char *s)
1297 {
1298 	static char *file = NULL;
1299 	static int filesz = 0;
1300 
1301 	int i = 0;
1302 
1303 	REALLOC(file, filesz, PATH_MAX, NULL);
1304 	while (i < filesz - 1	/* Worry about a possible trailing escape */
1305 	       && (file[i++] = (*s == '\\') ? *++s : *s))
1306 		s++;
1307 	return file;
1308 }
1309 
1310 
1311 void
signal_hup(int signo)1312 signal_hup(int signo)
1313 {
1314 	if (mutex)
1315 		sigflags |= (1 << (signo - 1));
1316 	else
1317 		handle_hup(signo);
1318 }
1319 
1320 
1321 void
signal_int(int signo)1322 signal_int(int signo)
1323 {
1324 	if (mutex)
1325 		sigflags |= (1 << (signo - 1));
1326 	else
1327 		handle_int(signo);
1328 }
1329 
1330 
1331 void
handle_hup(int signo)1332 handle_hup(int signo)
1333 {
1334 	char *hup = NULL;		/* hup filename */
1335 	char *s;
1336 	char ed_hup[] = "ed.hup";
1337 	size_t n;
1338 
1339 	if (!sigactive)
1340 		quit(1);
1341 	sigflags &= ~(1 << (signo - 1));
1342 	if (addr_last && write_file(ed_hup, "w", 1, addr_last) < 0 &&
1343 	    (s = getenv("HOME")) != NULL &&
1344 	    (n = strlen(s)) + 8 <= PATH_MAX &&	/* "ed.hup" + '/' */
1345 	    (hup = (char *) malloc(n + 10)) != NULL) {
1346 		strcpy(hup, s);
1347 		if (hup[n - 1] != '/')
1348 			hup[n] = '/', hup[n+1] = '\0';
1349 		strcat(hup, "ed.hup");
1350 		write_file(hup, "w", 1, addr_last);
1351 	}
1352 	quit(2);
1353 }
1354 
1355 
1356 void
handle_int(int signo)1357 handle_int(int signo)
1358 {
1359 	if (!sigactive)
1360 		quit(1);
1361 	sigflags &= ~(1 << (signo - 1));
1362 #ifdef _POSIX_SOURCE
1363 	siglongjmp(env, -1);
1364 #else
1365 	longjmp(env, -1);
1366 #endif
1367 }
1368 
1369 
1370 int cols = 72;				/* wrap column */
1371 
1372 void
handle_winch(int signo)1373 handle_winch(int signo)
1374 {
1375 	int save_errno = errno;
1376 
1377 	struct winsize ws;		/* window size structure */
1378 
1379 	sigflags &= ~(1 << (signo - 1));
1380 	if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1381 		if (ws.ws_row > 2) rows = ws.ws_row - 2;
1382 		if (ws.ws_col > 8) cols = ws.ws_col - 8;
1383 	}
1384 	errno = save_errno;
1385 }
1386 
1387 
1388 /* is_legal_filename: return a legal filename */
1389 int
is_legal_filename(char * s)1390 is_legal_filename(char *s)
1391 {
1392 	if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1393 		errmsg = "shell access restricted";
1394 		return 0;
1395 	}
1396 	return 1;
1397 }
1398