main.c revision 102410 
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
30static const char copyright[] =
31"@(#) Copyright (c) 1993 Andrew Moore, Talke Studio. \n\
32 All rights reserved.\n";
33#endif /* not lint */
34
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD: head/bin/ed/main.c 102410 2002-08-25 13:01:47Z charnier $");
37
38/*
39 * CREDITS
40 *
41 *	This program is based on the editor algorithm described in
42 *	Brian W. Kernighan and P. J. Plauger's book "Software Tools
43 *	in Pascal," Addison-Wesley, 1981.
44 *
45 *	The buffering algorithm is attributed to Rodney Ruddock of
46 *	the University of Guelph, Guelph, Ontario.
47 *
48 *	The cbc.c encryption code is adapted from
49 *	the bdes program by Matt Bishop of Dartmouth College,
50 *	Hanover, NH.
51 *
52 */
53
54#include <sys/types.h>
55
56#include <sys/ioctl.h>
57#include <sys/wait.h>
58#include <ctype.h>
59#include <locale.h>
60#include <pwd.h>
61#include <setjmp.h>
62
63#include "ed.h"
64
65
66#ifdef _POSIX_SOURCE
67sigjmp_buf env;
68#else
69jmp_buf env;
70#endif
71
72/* static buffers */
73char stdinbuf[1];		/* stdin buffer */
74char *shcmd;			/* shell command buffer */
75int shcmdsz;			/* shell command buffer size */
76int shcmdi;			/* shell command buffer index */
77char *ibuf;			/* ed command-line buffer */
78int ibufsz;			/* ed command-line buffer size */
79char *ibufp;			/* pointer to ed command-line buffer */
80
81/* global flags */
82int des = 0;			/* if set, use crypt(3) for i/o */
83int garrulous = 0;		/* if set, print all error messages */
84int isbinary;			/* if set, buffer contains ASCII NULs */
85int isglobal;			/* if set, doing a global command */
86int modified;			/* if set, buffer modified since last write */
87int mutex = 0;			/* if set, signals set "sigflags" */
88int red = 0;			/* if set, restrict shell/directory access */
89int scripted = 0;		/* if set, suppress diagnostics */
90int sigflags = 0;		/* if set, signals received while mutex set */
91int sigactive = 0;		/* if set, signal handlers are enabled */
92
93char old_filename[PATH_MAX] = "";	/* default filename */
94long current_addr;		/* current address in editor buffer */
95long addr_last;			/* last address in editor buffer */
96int lineno;			/* script line number */
97const char *prompt;		/* command-line prompt */
98const char *dps = "*";		/* default command-line prompt */
99
100const char usage[] = "usage: %s [-] [-sx] [-p string] [name]\n";
101
102/* ed: line editor */
103int
104main(int argc, char *argv[])
105{
106	int c, n;
107	long status = 0;
108#if __GNUC__
109	/* Avoid longjmp clobbering */
110	(void) &argc;
111	(void) &argv;
112#endif
113
114	(void)setlocale(LC_ALL, "");
115
116	red = (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
117top:
118	while ((c = getopt(argc, argv, "p:sx")) != -1)
119		switch(c) {
120		case 'p':				/* set prompt */
121			prompt = optarg;
122			break;
123		case 's':				/* run script */
124			scripted = 1;
125			break;
126		case 'x':				/* use crypt */
127#ifdef DES
128			des = get_keyword();
129#else
130			fprintf(stderr, "crypt unavailable\n?\n");
131#endif
132			break;
133
134		default:
135			fprintf(stderr, usage, argv[0]);
136			exit(1);
137		}
138	argv += optind;
139	argc -= optind;
140	if (argc && **argv == '-') {
141		scripted = 1;
142		if (argc > 1) {
143			optind = 1;
144			goto top;
145		}
146		argv++;
147		argc--;
148	}
149	/* assert: reliable signals! */
150#ifdef SIGWINCH
151	handle_winch(SIGWINCH);
152	if (isatty(0)) signal(SIGWINCH, handle_winch);
153#endif
154	signal(SIGHUP, signal_hup);
155	signal(SIGQUIT, SIG_IGN);
156	signal(SIGINT, signal_int);
157#ifdef _POSIX_SOURCE
158	if ((status = sigsetjmp(env, 1)))
159#else
160	if ((status = setjmp(env)))
161#endif
162	{
163		fputs("\n?\n", stderr);
164		errmsg = "interrupt";
165	} else {
166		init_buffers();
167		sigactive = 1;			/* enable signal handlers */
168		if (argc && **argv && is_legal_filename(*argv)) {
169			if (read_file(*argv, 0) < 0 && !isatty(0))
170				quit(2);
171			else if (**argv != '!')
172				if (strlcpy(old_filename, *argv, sizeof(old_filename))
173				    >= sizeof(old_filename))
174					quit(2);
175		} else if (argc) {
176			fputs("?\n", stderr);
177			if (**argv == '\0')
178				errmsg = "invalid filename";
179			if (!isatty(0))
180				quit(2);
181		}
182	}
183	for (;;) {
184		if (status < 0 && garrulous)
185			fprintf(stderr, "%s\n", errmsg);
186		if (prompt) {
187			printf("%s", prompt);
188			fflush(stdout);
189		}
190		if ((n = get_tty_line()) < 0) {
191			status = ERR;
192			continue;
193		} else if (n == 0) {
194			if (modified && !scripted) {
195				fputs("?\n", stderr);
196				errmsg = "warning: file modified";
197				if (!isatty(0)) {
198					fprintf(stderr, garrulous ?
199					    "script, line %d: %s\n" :
200					    "", lineno, errmsg);
201					quit(2);
202				}
203				clearerr(stdin);
204				modified = 0;
205				status = EMOD;
206				continue;
207			} else
208				quit(0);
209		} else if (ibuf[n - 1] != '\n') {
210			/* discard line */
211			errmsg = "unexpected end-of-file";
212			clearerr(stdin);
213			status = ERR;
214			continue;
215		}
216		isglobal = 0;
217		if ((status = extract_addr_range()) >= 0 &&
218		    (status = exec_command()) >= 0)
219			if (!status ||
220			    (status = display_lines(current_addr, current_addr,
221			        status)) >= 0)
222				continue;
223		switch (status) {
224		case EOF:
225			quit(0);
226		case EMOD:
227			modified = 0;
228			fputs("?\n", stderr);		/* give warning */
229			errmsg = "warning: file modified";
230			if (!isatty(0)) {
231				fprintf(stderr, garrulous ?
232				    "script, line %d: %s\n" :
233				    "", lineno, errmsg);
234				quit(2);
235			}
236			break;
237		case FATAL:
238			if (!isatty(0))
239				fprintf(stderr, garrulous ?
240				    "script, line %d: %s\n" : "",
241				    lineno, errmsg);
242			else
243				fprintf(stderr, garrulous ? "%s\n" : "",
244				    errmsg);
245			quit(3);
246		default:
247			fputs("?\n", stderr);
248			if (!isatty(0)) {
249				fprintf(stderr, garrulous ?
250				    "script, line %d: %s\n" : "",
251				    lineno, errmsg);
252				quit(2);
253			}
254			break;
255		}
256	}
257	/*NOTREACHED*/
258}
259
260long first_addr, second_addr, addr_cnt;
261
262/* extract_addr_range: get line addresses from the command buffer until an
263   illegal address is seen; return status */
264int
265extract_addr_range(void)
266{
267	long addr;
268
269	addr_cnt = 0;
270	first_addr = second_addr = current_addr;
271	while ((addr = next_addr()) >= 0) {
272		addr_cnt++;
273		first_addr = second_addr;
274		second_addr = addr;
275		if (*ibufp != ',' && *ibufp != ';')
276			break;
277		else if (*ibufp++ == ';')
278			current_addr = addr;
279	}
280	if ((addr_cnt = min(addr_cnt, 2)) == 1 || second_addr != addr)
281		first_addr = second_addr;
282	return (addr == ERR) ? ERR : 0;
283}
284
285
286#define SKIP_BLANKS() while (isspace((unsigned char)*ibufp) && *ibufp != '\n') ibufp++
287
288#define MUST_BE_FIRST() do {					\
289	if (!first) {						\
290		errmsg = "invalid address";			\
291		return ERR;					\
292	}							\
293} while (0);
294
295/*  next_addr: return the next line address in the command buffer */
296long
297next_addr(void)
298{
299	const char *hd;
300	long addr = current_addr;
301	long n;
302	int first = 1;
303	int c;
304
305	SKIP_BLANKS();
306	for (hd = ibufp;; first = 0)
307		switch (c = *ibufp) {
308		case '+':
309		case '\t':
310		case ' ':
311		case '-':
312		case '^':
313			ibufp++;
314			SKIP_BLANKS();
315			if (isdigit((unsigned char)*ibufp)) {
316				STRTOL(n, ibufp);
317				addr += (c == '-' || c == '^') ? -n : n;
318			} else if (!isspace((unsigned char)c))
319				addr += (c == '-' || c == '^') ? -1 : 1;
320			break;
321		case '0': case '1': case '2':
322		case '3': case '4': case '5':
323		case '6': case '7': case '8': case '9':
324			MUST_BE_FIRST();
325			STRTOL(addr, ibufp);
326			break;
327		case '.':
328		case '$':
329			MUST_BE_FIRST();
330			ibufp++;
331			addr = (c == '.') ? current_addr : addr_last;
332			break;
333		case '/':
334		case '?':
335			MUST_BE_FIRST();
336			if ((addr = get_matching_node_addr(
337			    get_compiled_pattern(), c == '/')) < 0)
338				return ERR;
339			else if (c == *ibufp)
340				ibufp++;
341			break;
342		case '\'':
343			MUST_BE_FIRST();
344			ibufp++;
345			if ((addr = get_marked_node_addr(*ibufp++)) < 0)
346				return ERR;
347			break;
348		case '%':
349		case ',':
350		case ';':
351			if (first) {
352				ibufp++;
353				addr_cnt++;
354				second_addr = (c == ';') ? current_addr : 1;
355				addr = addr_last;
356				break;
357			}
358			/* FALLTHROUGH */
359		default:
360			if (ibufp == hd)
361				return EOF;
362			else if (addr < 0 || addr_last < addr) {
363				errmsg = "invalid address";
364				return ERR;
365			} else
366				return addr;
367		}
368	/* NOTREACHED */
369}
370
371
372#ifdef 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	else if (addr_cnt == 0) { \
382		errmsg = "destination expected"; \
383		return ERR; \
384	} else if (second_addr < 0 || addr_last < second_addr) { \
385		errmsg = "invalid address"; \
386		return ERR; \
387	} \
388	addr = second_addr; \
389	first_addr = ol1, second_addr = ol2; \
390}
391#else	/* BACKWARDS */
392/* GET_THIRD_ADDR: get a legal address from the command buffer */
393#define GET_THIRD_ADDR(addr) \
394{ \
395	long ol1, ol2; \
396\
397	ol1 = first_addr, ol2 = second_addr; \
398	if (extract_addr_range() < 0) \
399		return ERR; \
400	if (second_addr < 0 || addr_last < second_addr) { \
401		errmsg = "invalid address"; \
402		return ERR; \
403	} \
404	addr = second_addr; \
405	first_addr = ol1, second_addr = ol2; \
406}
407#endif
408
409
410/* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
411#define GET_COMMAND_SUFFIX() { \
412	int done = 0; \
413	do { \
414		switch(*ibufp) { \
415		case 'p': \
416			gflag |= GPR, ibufp++; \
417			break; \
418		case 'l': \
419			gflag |= GLS, ibufp++; \
420			break; \
421		case 'n': \
422			gflag |= GNP, ibufp++; \
423			break; \
424		default: \
425			done++; \
426		} \
427	} while (!done); \
428	if (*ibufp++ != '\n') { \
429		errmsg = "invalid command suffix"; \
430		return ERR; \
431	} \
432}
433
434
435/* sflags */
436#define SGG 001		/* complement previous global substitute suffix */
437#define SGP 002		/* complement previous print suffix */
438#define SGR 004		/* use last regex instead of last pat */
439#define SGF 010		/* repeat last substitution */
440
441int patlock = 0;	/* if set, pattern not freed by get_compiled_pattern() */
442
443long rows = 22;		/* scroll length: ws_row - 2 */
444
445/* exec_command: execute the next command in command buffer; return print
446   request, if any */
447int
448exec_command(void)
449{
450	static pattern_t *pat = NULL;
451	static int sgflag = 0;
452	static long sgnum = 0;
453
454	pattern_t *tpat;
455	char *fnp;
456	int gflag = 0;
457	int sflags = 0;
458	long addr = 0;
459	int n = 0;
460	int c;
461
462	SKIP_BLANKS();
463	switch(c = *ibufp++) {
464	case 'a':
465		GET_COMMAND_SUFFIX();
466		if (!isglobal) clear_undo_stack();
467		if (append_lines(second_addr) < 0)
468			return ERR;
469		break;
470	case 'c':
471		if (check_addr_range(current_addr, current_addr) < 0)
472			return ERR;
473		GET_COMMAND_SUFFIX();
474		if (!isglobal) clear_undo_stack();
475		if (delete_lines(first_addr, second_addr) < 0 ||
476		    append_lines(current_addr) < 0)
477			return ERR;
478		break;
479	case 'd':
480		if (check_addr_range(current_addr, current_addr) < 0)
481			return ERR;
482		GET_COMMAND_SUFFIX();
483		if (!isglobal) clear_undo_stack();
484		if (delete_lines(first_addr, second_addr) < 0)
485			return ERR;
486		else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
487			current_addr = addr;
488		break;
489	case 'e':
490		if (modified && !scripted)
491			return EMOD;
492		/* FALLTHROUGH */
493	case 'E':
494		if (addr_cnt > 0) {
495			errmsg = "unexpected address";
496			return ERR;
497		} else if (!isspace((unsigned char)*ibufp)) {
498			errmsg = "unexpected command suffix";
499			return ERR;
500		} else if ((fnp = get_filename()) == NULL)
501			return ERR;
502		GET_COMMAND_SUFFIX();
503		if (delete_lines(1, addr_last) < 0)
504			return ERR;
505		clear_undo_stack();
506		if (close_sbuf() < 0)
507			return ERR;
508		else if (open_sbuf() < 0)
509			return FATAL;
510		if (*fnp && *fnp != '!') strcpy(old_filename, fnp);
511#ifdef BACKWARDS
512		if (*fnp == '\0' && *old_filename == '\0') {
513			errmsg = "no current filename";
514			return ERR;
515		}
516#endif
517		if (read_file(*fnp ? fnp : old_filename, 0) < 0)
518			return ERR;
519		clear_undo_stack();
520		modified = 0;
521		u_current_addr = u_addr_last = -1;
522		break;
523	case 'f':
524		if (addr_cnt > 0) {
525			errmsg = "unexpected address";
526			return ERR;
527		} else if (!isspace((unsigned char)*ibufp)) {
528			errmsg = "unexpected command suffix";
529			return ERR;
530		} else if ((fnp = get_filename()) == NULL)
531			return ERR;
532		else if (*fnp == '!') {
533			errmsg = "invalid redirection";
534			return ERR;
535		}
536		GET_COMMAND_SUFFIX();
537		if (*fnp) strcpy(old_filename, fnp);
538		printf("%s\n", strip_escapes(old_filename));
539		break;
540	case 'g':
541	case 'v':
542	case 'G':
543	case 'V':
544		if (isglobal) {
545			errmsg = "cannot nest global commands";
546			return ERR;
547		} else if (check_addr_range(1, addr_last) < 0)
548			return ERR;
549		else if (build_active_list(c == 'g' || c == 'G') < 0)
550			return ERR;
551		else if ((n = (c == 'G' || c == 'V')))
552			GET_COMMAND_SUFFIX();
553		isglobal++;
554		if (exec_global(n, gflag) < 0)
555			return ERR;
556		break;
557	case 'h':
558		if (addr_cnt > 0) {
559			errmsg = "unexpected address";
560			return ERR;
561		}
562		GET_COMMAND_SUFFIX();
563		if (*errmsg) fprintf(stderr, "%s\n", errmsg);
564		break;
565	case 'H':
566		if (addr_cnt > 0) {
567			errmsg = "unexpected address";
568			return ERR;
569		}
570		GET_COMMAND_SUFFIX();
571		if ((garrulous = 1 - garrulous) && *errmsg)
572			fprintf(stderr, "%s\n", errmsg);
573		break;
574	case 'i':
575		if (second_addr == 0) {
576			errmsg = "invalid address";
577			return ERR;
578		}
579		GET_COMMAND_SUFFIX();
580		if (!isglobal) clear_undo_stack();
581		if (append_lines(second_addr - 1) < 0)
582			return ERR;
583		break;
584	case 'j':
585		if (check_addr_range(current_addr, current_addr + 1) < 0)
586			return ERR;
587		GET_COMMAND_SUFFIX();
588		if (!isglobal) clear_undo_stack();
589		if (first_addr != second_addr &&
590		    join_lines(first_addr, second_addr) < 0)
591			return ERR;
592		break;
593	case 'k':
594		c = *ibufp++;
595		if (second_addr == 0) {
596			errmsg = "invalid address";
597			return ERR;
598		}
599		GET_COMMAND_SUFFIX();
600		if (mark_line_node(get_addressed_line_node(second_addr), c) < 0)
601			return ERR;
602		break;
603	case 'l':
604		if (check_addr_range(current_addr, current_addr) < 0)
605			return ERR;
606		GET_COMMAND_SUFFIX();
607		if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
608			return ERR;
609		gflag = 0;
610		break;
611	case 'm':
612		if (check_addr_range(current_addr, current_addr) < 0)
613			return ERR;
614		GET_THIRD_ADDR(addr);
615		if (first_addr <= addr && addr < second_addr) {
616			errmsg = "invalid destination";
617			return ERR;
618		}
619		GET_COMMAND_SUFFIX();
620		if (!isglobal) clear_undo_stack();
621		if (move_lines(addr) < 0)
622			return ERR;
623		break;
624	case 'n':
625		if (check_addr_range(current_addr, current_addr) < 0)
626			return ERR;
627		GET_COMMAND_SUFFIX();
628		if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
629			return ERR;
630		gflag = 0;
631		break;
632	case 'p':
633		if (check_addr_range(current_addr, current_addr) < 0)
634			return ERR;
635		GET_COMMAND_SUFFIX();
636		if (display_lines(first_addr, second_addr, gflag | GPR) < 0)
637			return ERR;
638		gflag = 0;
639		break;
640	case 'P':
641		if (addr_cnt > 0) {
642			errmsg = "unexpected address";
643			return ERR;
644		}
645		GET_COMMAND_SUFFIX();
646		prompt = prompt ? NULL : optarg ? optarg : dps;
647		break;
648	case 'q':
649	case 'Q':
650		if (addr_cnt > 0) {
651			errmsg = "unexpected address";
652			return ERR;
653		}
654		GET_COMMAND_SUFFIX();
655		gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
656		break;
657	case 'r':
658		if (!isspace((unsigned char)*ibufp)) {
659			errmsg = "unexpected command suffix";
660			return ERR;
661		} else if (addr_cnt == 0)
662			second_addr = addr_last;
663		if ((fnp = get_filename()) == NULL)
664			return ERR;
665		GET_COMMAND_SUFFIX();
666		if (!isglobal) clear_undo_stack();
667		if (*old_filename == '\0' && *fnp != '!')
668			strcpy(old_filename, fnp);
669#ifdef BACKWARDS
670		if (*fnp == '\0' && *old_filename == '\0') {
671			errmsg = "no current filename";
672			return ERR;
673		}
674#endif
675		if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
676			return ERR;
677		else if (addr && addr != addr_last)
678			modified = 1;
679		break;
680	case 's':
681		do {
682			switch(*ibufp) {
683			case '\n':
684				sflags |=SGF;
685				break;
686			case 'g':
687				sflags |= SGG;
688				ibufp++;
689				break;
690			case 'p':
691				sflags |= SGP;
692				ibufp++;
693				break;
694			case 'r':
695				sflags |= SGR;
696				ibufp++;
697				break;
698			case '0': case '1': case '2': case '3': case '4':
699			case '5': case '6': case '7': case '8': case '9':
700				STRTOL(sgnum, ibufp);
701				sflags |= SGF;
702				sgflag &= ~GSG;		/* override GSG */
703				break;
704			default:
705				if (sflags) {
706					errmsg = "invalid command suffix";
707					return ERR;
708				}
709			}
710		} while (sflags && *ibufp != '\n');
711		if (sflags && !pat) {
712			errmsg = "no previous substitution";
713			return ERR;
714		} else if (sflags & SGG)
715			sgnum = 0;		/* override numeric arg */
716		if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
717			errmsg = "invalid pattern delimiter";
718			return ERR;
719		}
720		tpat = pat;
721		SPL1();
722		if ((!sflags || (sflags & SGR)) &&
723		    (tpat = get_compiled_pattern()) == NULL) {
724		 	SPL0();
725			return ERR;
726		} else if (tpat != pat) {
727			if (pat) {
728				regfree(pat);
729				free(pat);
730			}
731			pat = tpat;
732			patlock = 1;		/* reserve pattern */
733		}
734		SPL0();
735		if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
736			return ERR;
737		else if (isglobal)
738			sgflag |= GLB;
739		else
740			sgflag &= ~GLB;
741		if (sflags & SGG)
742			sgflag ^= GSG;
743		if (sflags & SGP)
744			sgflag ^= GPR, sgflag &= ~(GLS | GNP);
745		do {
746			switch(*ibufp) {
747			case 'p':
748				sgflag |= GPR, ibufp++;
749				break;
750			case 'l':
751				sgflag |= GLS, ibufp++;
752				break;
753			case 'n':
754				sgflag |= GNP, ibufp++;
755				break;
756			default:
757				n++;
758			}
759		} while (!n);
760		if (check_addr_range(current_addr, current_addr) < 0)
761			return ERR;
762		GET_COMMAND_SUFFIX();
763		if (!isglobal) clear_undo_stack();
764		if (search_and_replace(pat, sgflag, sgnum) < 0)
765			return ERR;
766		break;
767	case 't':
768		if (check_addr_range(current_addr, current_addr) < 0)
769			return ERR;
770		GET_THIRD_ADDR(addr);
771		GET_COMMAND_SUFFIX();
772		if (!isglobal) clear_undo_stack();
773		if (copy_lines(addr) < 0)
774			return ERR;
775		break;
776	case 'u':
777		if (addr_cnt > 0) {
778			errmsg = "unexpected address";
779			return ERR;
780		}
781		GET_COMMAND_SUFFIX();
782		if (pop_undo_stack() < 0)
783			return ERR;
784		break;
785	case 'w':
786	case 'W':
787		if ((n = *ibufp) == 'q' || n == 'Q') {
788			gflag = EOF;
789			ibufp++;
790		}
791		if (!isspace((unsigned char)*ibufp)) {
792			errmsg = "unexpected command suffix";
793			return ERR;
794		} else if ((fnp = get_filename()) == NULL)
795			return ERR;
796		if (addr_cnt == 0 && !addr_last)
797			first_addr = second_addr = 0;
798		else if (check_addr_range(1, addr_last) < 0)
799			return ERR;
800		GET_COMMAND_SUFFIX();
801		if (*old_filename == '\0' && *fnp != '!')
802			strcpy(old_filename, fnp);
803#ifdef BACKWARDS
804		if (*fnp == '\0' && *old_filename == '\0') {
805			errmsg = "no current filename";
806			return ERR;
807		}
808#endif
809		if ((addr = write_file(*fnp ? fnp : old_filename,
810		    (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
811			return ERR;
812		else if (addr == addr_last)
813			modified = 0;
814		else if (modified && !scripted && n == 'q')
815			gflag = EMOD;
816		break;
817	case 'x':
818		if (addr_cnt > 0) {
819			errmsg = "unexpected address";
820			return ERR;
821		}
822		GET_COMMAND_SUFFIX();
823#ifdef DES
824		des = get_keyword();
825#else
826		errmsg = "crypt unavailable";
827		return ERR;
828#endif
829		break;
830	case 'z':
831#ifdef BACKWARDS
832		if (check_addr_range(first_addr = 1, current_addr + 1) < 0)
833#else
834		if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0)
835#endif
836			return ERR;
837		else if ('0' < *ibufp && *ibufp <= '9')
838			STRTOL(rows, ibufp);
839		GET_COMMAND_SUFFIX();
840		if (display_lines(second_addr, min(addr_last,
841		    second_addr + rows), gflag) < 0)
842			return ERR;
843		gflag = 0;
844		break;
845	case '=':
846		GET_COMMAND_SUFFIX();
847		printf("%ld\n", addr_cnt ? second_addr : addr_last);
848		break;
849	case '!':
850		if (addr_cnt > 0) {
851			errmsg = "unexpected address";
852			return ERR;
853		} else if ((sflags = get_shell_command()) < 0)
854			return ERR;
855		GET_COMMAND_SUFFIX();
856		if (sflags) printf("%s\n", shcmd + 1);
857		system(shcmd + 1);
858		if (!scripted) printf("!\n");
859		break;
860	case '\n':
861#ifdef BACKWARDS
862		if (check_addr_range(first_addr = 1, current_addr + 1) < 0
863#else
864		if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0
865#endif
866		 || display_lines(second_addr, second_addr, 0) < 0)
867			return ERR;
868		break;
869	default:
870		errmsg = "unknown command";
871		return ERR;
872	}
873	return gflag;
874}
875
876
877/* check_addr_range: return status of address range check */
878int
879check_addr_range(long n, long m)
880{
881	if (addr_cnt == 0) {
882		first_addr = n;
883		second_addr = m;
884	}
885	if (first_addr > second_addr || 1 > first_addr ||
886	    second_addr > addr_last) {
887		errmsg = "invalid address";
888		return ERR;
889	}
890	return 0;
891}
892
893
894/* get_matching_node_addr: return the address of the next line matching a
895   pattern in a given direction.  wrap around begin/end of editor buffer if
896   necessary */
897long
898get_matching_node_addr(pattern_t *pat, int dir)
899{
900	char *s;
901	long n = current_addr;
902	line_t *lp;
903
904	if (!pat) return ERR;
905	do {
906	       if ((n = dir ? INC_MOD(n, addr_last) : DEC_MOD(n, addr_last))) {
907			lp = get_addressed_line_node(n);
908			if ((s = get_sbuf_line(lp)) == NULL)
909				return ERR;
910			if (isbinary)
911				NUL_TO_NEWLINE(s, lp->len);
912			if (!regexec(pat, s, 0, NULL, 0))
913				return n;
914	       }
915	} while (n != current_addr);
916	errmsg = "no match";
917	return  ERR;
918}
919
920
921/* get_filename: return pointer to copy of filename in the command buffer */
922char *
923get_filename(void)
924{
925	static char *file = NULL;
926	static int filesz = 0;
927
928	int n;
929
930	if (*ibufp != '\n') {
931		SKIP_BLANKS();
932		if (*ibufp == '\n') {
933			errmsg = "invalid filename";
934			return NULL;
935		} else if ((ibufp = get_extended_line(&n, 1)) == NULL)
936			return NULL;
937		else if (*ibufp == '!') {
938			ibufp++;
939			if ((n = get_shell_command()) < 0)
940				return NULL;
941			if (n)
942				printf("%s\n", shcmd + 1);
943			return shcmd;
944		} else if (n > PATH_MAX - 1) {
945			errmsg = "filename too long";
946			return  NULL;
947		}
948	}
949#ifndef BACKWARDS
950	else if (*old_filename == '\0') {
951		errmsg = "no current filename";
952		return  NULL;
953	}
954#endif
955	REALLOC(file, filesz, PATH_MAX, NULL);
956	for (n = 0; *ibufp != '\n';)
957		file[n++] = *ibufp++;
958	file[n] = '\0';
959	return is_legal_filename(file) ? file : NULL;
960}
961
962
963/* get_shell_command: read a shell command from stdin; return substitution
964   status */
965int
966get_shell_command(void)
967{
968	static char *buf = NULL;
969	static int n = 0;
970
971	char *s;			/* substitution char pointer */
972	int i = 0;
973	int j = 0;
974
975	if (red) {
976		errmsg = "shell access restricted";
977		return ERR;
978	} else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
979		return ERR;
980	REALLOC(buf, n, j + 1, ERR);
981	buf[i++] = '!';			/* prefix command w/ bang */
982	while (*ibufp != '\n')
983		switch (*ibufp) {
984		default:
985			REALLOC(buf, n, i + 2, ERR);
986			buf[i++] = *ibufp;
987			if (*ibufp++ == '\\')
988				buf[i++] = *ibufp++;
989			break;
990		case '!':
991			if (s != ibufp) {
992				REALLOC(buf, n, i + 1, ERR);
993				buf[i++] = *ibufp++;
994			}
995#ifdef BACKWARDS
996			else if (shcmd == NULL || *(shcmd + 1) == '\0')
997#else
998			else if (shcmd == NULL)
999#endif
1000			{
1001				errmsg = "no previous command";
1002				return ERR;
1003			} else {
1004				REALLOC(buf, n, i + shcmdi, ERR);
1005				for (s = shcmd + 1; s < shcmd + shcmdi;)
1006					buf[i++] = *s++;
1007				s = ibufp++;
1008			}
1009			break;
1010		case '%':
1011			if (*old_filename  == '\0') {
1012				errmsg = "no current filename";
1013				return ERR;
1014			}
1015			j = strlen(s = strip_escapes(old_filename));
1016			REALLOC(buf, n, i + j, ERR);
1017			while (j--)
1018				buf[i++] = *s++;
1019			s = ibufp++;
1020			break;
1021		}
1022	REALLOC(shcmd, shcmdsz, i + 1, ERR);
1023	memcpy(shcmd, buf, i);
1024	shcmd[shcmdi = i] = '\0';
1025	return *s == '!' || *s == '%';
1026}
1027
1028
1029/* append_lines: insert text from stdin to after line n; stop when either a
1030   single period is read or EOF; return status */
1031int
1032append_lines(long n)
1033{
1034	int l;
1035	const char *lp = ibuf;
1036	const char *eot;
1037	undo_t *up = NULL;
1038
1039	for (current_addr = n;;) {
1040		if (!isglobal) {
1041			if ((l = get_tty_line()) < 0)
1042				return ERR;
1043			else if (l == 0 || ibuf[l - 1] != '\n') {
1044				clearerr(stdin);
1045				return  l ? EOF : 0;
1046			}
1047			lp = ibuf;
1048		} else if (*(lp = ibufp) == '\0')
1049			return 0;
1050		else {
1051			while (*ibufp++ != '\n')
1052				;
1053			l = ibufp - lp;
1054		}
1055		if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1056			return 0;
1057		}
1058		eot = lp + l;
1059		SPL1();
1060		do {
1061			if ((lp = put_sbuf_line(lp)) == NULL) {
1062				SPL0();
1063				return ERR;
1064			} else if (up)
1065				up->t = get_addressed_line_node(current_addr);
1066			else if ((up = push_undo_stack(UADD, current_addr,
1067			    current_addr)) == NULL) {
1068				SPL0();
1069				return ERR;
1070			}
1071		} while (lp != eot);
1072		modified = 1;
1073		SPL0();
1074	}
1075	/* NOTREACHED */
1076}
1077
1078
1079/* join_lines: replace a range of lines with the joined text of those lines */
1080int
1081join_lines(long from, long to)
1082{
1083	static char *buf = NULL;
1084	static int n;
1085
1086	char *s;
1087	int size = 0;
1088	line_t *bp, *ep;
1089
1090	ep = get_addressed_line_node(INC_MOD(to, addr_last));
1091	bp = get_addressed_line_node(from);
1092	for (; bp != ep; bp = bp->q_forw) {
1093		if ((s = get_sbuf_line(bp)) == NULL)
1094			return ERR;
1095		REALLOC(buf, n, size + bp->len, ERR);
1096		memcpy(buf + size, s, bp->len);
1097		size += bp->len;
1098	}
1099	REALLOC(buf, n, size + 2, ERR);
1100	memcpy(buf + size, "\n", 2);
1101	if (delete_lines(from, to) < 0)
1102		return ERR;
1103	current_addr = from - 1;
1104	SPL1();
1105	if (put_sbuf_line(buf) == NULL ||
1106	    push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1107		SPL0();
1108		return ERR;
1109	}
1110	modified = 1;
1111	SPL0();
1112	return 0;
1113}
1114
1115
1116/* move_lines: move a range of lines */
1117int
1118move_lines(long addr)
1119{
1120	line_t *b1, *a1, *b2, *a2;
1121	long n = INC_MOD(second_addr, addr_last);
1122	long p = first_addr - 1;
1123	int done = (addr == first_addr - 1 || addr == second_addr);
1124
1125	SPL1();
1126	if (done) {
1127		a2 = get_addressed_line_node(n);
1128		b2 = get_addressed_line_node(p);
1129		current_addr = second_addr;
1130	} else if (push_undo_stack(UMOV, p, n) == NULL ||
1131	    push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1132		SPL0();
1133		return ERR;
1134	} else {
1135		a1 = get_addressed_line_node(n);
1136		if (addr < first_addr) {
1137			b1 = get_addressed_line_node(p);
1138			b2 = get_addressed_line_node(addr);
1139					/* this get_addressed_line_node last! */
1140		} else {
1141			b2 = get_addressed_line_node(addr);
1142			b1 = get_addressed_line_node(p);
1143					/* this get_addressed_line_node last! */
1144		}
1145		a2 = b2->q_forw;
1146		REQUE(b2, b1->q_forw);
1147		REQUE(a1->q_back, a2);
1148		REQUE(b1, a1);
1149		current_addr = addr + ((addr < first_addr) ?
1150		    second_addr - first_addr + 1 : 0);
1151	}
1152	if (isglobal)
1153		unset_active_nodes(b2->q_forw, a2);
1154	modified = 1;
1155	SPL0();
1156	return 0;
1157}
1158
1159
1160/* copy_lines: copy a range of lines; return status */
1161int
1162copy_lines(long addr)
1163{
1164	line_t *lp, *np = get_addressed_line_node(first_addr);
1165	undo_t *up = NULL;
1166	long n = second_addr - first_addr + 1;
1167	long m = 0;
1168
1169	current_addr = addr;
1170	if (first_addr <= addr && addr < second_addr) {
1171		n =  addr - first_addr + 1;
1172		m = second_addr - addr;
1173	}
1174	for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1175		for (; n-- > 0; np = np->q_forw) {
1176			SPL1();
1177			if ((lp = dup_line_node(np)) == NULL) {
1178				SPL0();
1179				return ERR;
1180			}
1181			add_line_node(lp);
1182			if (up)
1183				up->t = lp;
1184			else if ((up = push_undo_stack(UADD, current_addr,
1185			    current_addr)) == NULL) {
1186				SPL0();
1187				return ERR;
1188			}
1189			modified = 1;
1190			SPL0();
1191		}
1192	return 0;
1193}
1194
1195
1196/* delete_lines: delete a range of lines */
1197int
1198delete_lines(long from, long to)
1199{
1200	line_t *n, *p;
1201
1202	SPL1();
1203	if (push_undo_stack(UDEL, from, to) == NULL) {
1204		SPL0();
1205		return ERR;
1206	}
1207	n = get_addressed_line_node(INC_MOD(to, addr_last));
1208	p = get_addressed_line_node(from - 1);
1209					/* this get_addressed_line_node last! */
1210	if (isglobal)
1211		unset_active_nodes(p->q_forw, n);
1212	REQUE(p, n);
1213	addr_last -= to - from + 1;
1214	current_addr = from - 1;
1215	modified = 1;
1216	SPL0();
1217	return 0;
1218}
1219
1220
1221/* display_lines: print a range of lines to stdout */
1222int
1223display_lines(long from, long to, int gflag)
1224{
1225	line_t *bp;
1226	line_t *ep;
1227	char *s;
1228
1229	if (!from) {
1230		errmsg = "invalid address";
1231		return ERR;
1232	}
1233	ep = get_addressed_line_node(INC_MOD(to, addr_last));
1234	bp = get_addressed_line_node(from);
1235	for (; bp != ep; bp = bp->q_forw) {
1236		if ((s = get_sbuf_line(bp)) == NULL)
1237			return ERR;
1238		if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1239			return ERR;
1240	}
1241	return 0;
1242}
1243
1244
1245#define MAXMARK 26			/* max number of marks */
1246
1247line_t	*mark[MAXMARK];			/* line markers */
1248int markno;				/* line marker count */
1249
1250/* mark_line_node: set a line node mark */
1251int
1252mark_line_node(line_t *lp, int n)
1253{
1254	if (!islower((unsigned char)n)) {
1255		errmsg = "invalid mark character";
1256		return ERR;
1257	} else if (mark[n - 'a'] == NULL)
1258		markno++;
1259	mark[n - 'a'] = lp;
1260	return 0;
1261}
1262
1263
1264/* get_marked_node_addr: return address of a marked line */
1265long
1266get_marked_node_addr(int n)
1267{
1268	if (!islower((unsigned char)n)) {
1269		errmsg = "invalid mark character";
1270		return ERR;
1271	}
1272	return get_line_node_addr(mark[n - 'a']);
1273}
1274
1275
1276/* unmark_line_node: clear line node mark */
1277void
1278unmark_line_node(line_t *lp)
1279{
1280	int i;
1281
1282	for (i = 0; markno && i < MAXMARK; i++)
1283		if (mark[i] == lp) {
1284			mark[i] = NULL;
1285			markno--;
1286		}
1287}
1288
1289
1290/* dup_line_node: return a pointer to a copy of a line node */
1291line_t *
1292dup_line_node(line_t *lp)
1293{
1294	line_t *np;
1295
1296	if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1297		fprintf(stderr, "%s\n", strerror(errno));
1298		errmsg = "out of memory";
1299		return NULL;
1300	}
1301	np->seek = lp->seek;
1302	np->len = lp->len;
1303	return np;
1304}
1305
1306
1307/* has_trailing_escape:  return the parity of escapes preceding a character
1308   in a string */
1309int
1310has_trailing_escape(char *s, char *t)
1311{
1312    return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1313}
1314
1315
1316/* strip_escapes: return copy of escaped string of at most length PATH_MAX */
1317char *
1318strip_escapes(char *s)
1319{
1320	static char *file = NULL;
1321	static int filesz = 0;
1322
1323	int i = 0;
1324
1325	REALLOC(file, filesz, PATH_MAX, NULL);
1326	while (i < filesz - 1	/* Worry about a possible trailing escape */
1327	       && (file[i++] = (*s == '\\') ? *++s : *s))
1328		s++;
1329	return file;
1330}
1331
1332
1333void
1334signal_hup(int signo)
1335{
1336	if (mutex)
1337		sigflags |= (1 << (signo - 1));
1338	else
1339		handle_hup(signo);
1340}
1341
1342
1343void
1344signal_int(int signo)
1345{
1346	if (mutex)
1347		sigflags |= (1 << (signo - 1));
1348	else
1349		handle_int(signo);
1350}
1351
1352
1353void
1354handle_hup(int signo)
1355{
1356	char *hup = NULL;		/* hup filename */
1357	char *s;
1358	char ed_hup[] = "ed.hup";
1359	int n;
1360
1361	if (!sigactive)
1362		quit(1);
1363	sigflags &= ~(1 << (signo - 1));
1364	if (addr_last && write_file(ed_hup, "w", 1, addr_last) < 0 &&
1365	    (s = getenv("HOME")) != NULL &&
1366	    (n = strlen(s)) + 8 <= PATH_MAX &&	/* "ed.hup" + '/' */
1367	    (hup = (char *) malloc(n + 10)) != NULL) {
1368		strcpy(hup, s);
1369		if (hup[n - 1] != '/')
1370			hup[n] = '/', hup[n+1] = '\0';
1371		strcat(hup, "ed.hup");
1372		write_file(hup, "w", 1, addr_last);
1373	}
1374	quit(2);
1375}
1376
1377
1378void
1379handle_int(int signo)
1380{
1381	if (!sigactive)
1382		quit(1);
1383	sigflags &= ~(1 << (signo - 1));
1384#ifdef _POSIX_SOURCE
1385	siglongjmp(env, -1);
1386#else
1387	longjmp(env, -1);
1388#endif
1389}
1390
1391
1392int cols = 72;				/* wrap column */
1393
1394void
1395handle_winch(int signo)
1396{
1397	int save_errno = errno;
1398
1399	struct winsize ws;		/* window size structure */
1400
1401	sigflags &= ~(1 << (signo - 1));
1402	if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1403		if (ws.ws_row > 2) rows = ws.ws_row - 2;
1404		if (ws.ws_col > 8) cols = ws.ws_col - 8;
1405	}
1406	errno = save_errno;
1407}
1408
1409
1410/* is_legal_filename: return a legal filename */
1411int
1412is_legal_filename(char *s)
1413{
1414	if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1415		errmsg = "shell access restricted";
1416		return 0;
1417	}
1418	return 1;
1419}
1420