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