main.c revision 114433 
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: head/bin/ed/main.c 114433 2003-05-01 16:58:57Z obrien $");
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
69sigjmp_buf env;
70#else
71jmp_buf env;
72#endif
73
74/* static buffers */
75char stdinbuf[1];		/* stdin buffer */
76char *shcmd;			/* shell command buffer */
77int shcmdsz;			/* shell command buffer size */
78int 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 */
85int 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" */
90int 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 */
93int sigactive = 0;		/* if set, signal handlers are enabled */
94
95char 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 */
99const char *prompt;		/* command-line prompt */
100const char *dps = "*";		/* default command-line prompt */
101
102const char usage[] = "usage: %s [-] [-sx] [-p string] [name]\n";
103
104/* ed: line editor */
105int
106main(int argc, char *argv[])
107{
108	int c, n;
109	long status = 0;
110#if __GNUC__
111	/* Avoid longjmp clobbering */
112	(void) &argc;
113	(void) &argv;
114#endif
115
116	(void)setlocale(LC_ALL, "");
117
118	red = (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
119top:
120	while ((c = getopt(argc, argv, "p:sx")) != -1)
121		switch(c) {
122		case 'p':				/* set prompt */
123			prompt = optarg;
124			break;
125		case 's':				/* run script */
126			scripted = 1;
127			break;
128		case 'x':				/* use crypt */
129#ifdef DES
130			des = get_keyword();
131#else
132			fprintf(stderr, "crypt unavailable\n?\n");
133#endif
134			break;
135
136		default:
137			fprintf(stderr, usage, argv[0]);
138			exit(1);
139		}
140	argv += optind;
141	argc -= optind;
142	if (argc && **argv == '-') {
143		scripted = 1;
144		if (argc > 1) {
145			optind = 1;
146			goto top;
147		}
148		argv++;
149		argc--;
150	}
151	/* assert: reliable signals! */
152#ifdef SIGWINCH
153	handle_winch(SIGWINCH);
154	if (isatty(0)) signal(SIGWINCH, handle_winch);
155#endif
156	signal(SIGHUP, signal_hup);
157	signal(SIGQUIT, SIG_IGN);
158	signal(SIGINT, signal_int);
159#ifdef _POSIX_SOURCE
160	if ((status = sigsetjmp(env, 1)))
161#else
162	if ((status = setjmp(env)))
163#endif
164	{
165		fputs("\n?\n", stderr);
166		errmsg = "interrupt";
167	} else {
168		init_buffers();
169		sigactive = 1;			/* enable signal handlers */
170		if (argc && **argv && is_legal_filename(*argv)) {
171			if (read_file(*argv, 0) < 0 && !isatty(0))
172				quit(2);
173			else if (**argv != '!')
174				if (strlcpy(old_filename, *argv, sizeof(old_filename))
175				    >= sizeof(old_filename))
176					quit(2);
177		} else if (argc) {
178			fputs("?\n", stderr);
179			if (**argv == '\0')
180				errmsg = "invalid filename";
181			if (!isatty(0))
182				quit(2);
183		}
184	}
185	for (;;) {
186		if (status < 0 && garrulous)
187			fprintf(stderr, "%s\n", errmsg);
188		if (prompt) {
189			printf("%s", prompt);
190			fflush(stdout);
191		}
192		if ((n = get_tty_line()) < 0) {
193			status = ERR;
194			continue;
195		} else if (n == 0) {
196			if (modified && !scripted) {
197				fputs("?\n", stderr);
198				errmsg = "warning: file modified";
199				if (!isatty(0)) {
200					fprintf(stderr, garrulous ?
201					    "script, line %d: %s\n" :
202					    "", lineno, errmsg);
203					quit(2);
204				}
205				clearerr(stdin);
206				modified = 0;
207				status = EMOD;
208				continue;
209			} else
210				quit(0);
211		} else if (ibuf[n - 1] != '\n') {
212			/* discard line */
213			errmsg = "unexpected end-of-file";
214			clearerr(stdin);
215			status = ERR;
216			continue;
217		}
218		isglobal = 0;
219		if ((status = extract_addr_range()) >= 0 &&
220		    (status = exec_command()) >= 0)
221			if (!status ||
222			    (status = display_lines(current_addr, current_addr,
223			        status)) >= 0)
224				continue;
225		switch (status) {
226		case EOF:
227			quit(0);
228		case EMOD:
229			modified = 0;
230			fputs("?\n", stderr);		/* give warning */
231			errmsg = "warning: file modified";
232			if (!isatty(0)) {
233				fprintf(stderr, garrulous ?
234				    "script, line %d: %s\n" :
235				    "", lineno, errmsg);
236				quit(2);
237			}
238			break;
239		case FATAL:
240			if (!isatty(0))
241				fprintf(stderr, garrulous ?
242				    "script, line %d: %s\n" : "",
243				    lineno, errmsg);
244			else
245				fprintf(stderr, garrulous ? "%s\n" : "",
246				    errmsg);
247			quit(3);
248		default:
249			fputs("?\n", stderr);
250			if (!isatty(0)) {
251				fprintf(stderr, garrulous ?
252				    "script, line %d: %s\n" : "",
253				    lineno, errmsg);
254				quit(2);
255			}
256			break;
257		}
258	}
259	/*NOTREACHED*/
260}
261
262long first_addr, second_addr, addr_cnt;
263
264/* extract_addr_range: get line addresses from the command buffer until an
265   illegal address is seen; return status */
266int
267extract_addr_range(void)
268{
269	long addr;
270
271	addr_cnt = 0;
272	first_addr = second_addr = current_addr;
273	while ((addr = next_addr()) >= 0) {
274		addr_cnt++;
275		first_addr = second_addr;
276		second_addr = addr;
277		if (*ibufp != ',' && *ibufp != ';')
278			break;
279		else if (*ibufp++ == ';')
280			current_addr = addr;
281	}
282	if ((addr_cnt = min(addr_cnt, 2)) == 1 || second_addr != addr)
283		first_addr = second_addr;
284	return (addr == ERR) ? ERR : 0;
285}
286
287
288#define SKIP_BLANKS() while (isspace((unsigned char)*ibufp) && *ibufp != '\n') ibufp++
289
290#define MUST_BE_FIRST() do {					\
291	if (!first) {						\
292		errmsg = "invalid address";			\
293		return ERR;					\
294	}							\
295} while (0);
296
297/*  next_addr: return the next line address in the command buffer */
298long
299next_addr(void)
300{
301	const char *hd;
302	long addr = current_addr;
303	long n;
304	int first = 1;
305	int c;
306
307	SKIP_BLANKS();
308	for (hd = ibufp;; first = 0)
309		switch (c = *ibufp) {
310		case '+':
311		case '\t':
312		case ' ':
313		case '-':
314		case '^':
315			ibufp++;
316			SKIP_BLANKS();
317			if (isdigit((unsigned char)*ibufp)) {
318				STRTOL(n, ibufp);
319				addr += (c == '-' || c == '^') ? -n : n;
320			} else if (!isspace((unsigned char)c))
321				addr += (c == '-' || c == '^') ? -1 : 1;
322			break;
323		case '0': case '1': case '2':
324		case '3': case '4': case '5':
325		case '6': case '7': case '8': case '9':
326			MUST_BE_FIRST();
327			STRTOL(addr, ibufp);
328			break;
329		case '.':
330		case '$':
331			MUST_BE_FIRST();
332			ibufp++;
333			addr = (c == '.') ? current_addr : addr_last;
334			break;
335		case '/':
336		case '?':
337			MUST_BE_FIRST();
338			if ((addr = get_matching_node_addr(
339			    get_compiled_pattern(), c == '/')) < 0)
340				return ERR;
341			else if (c == *ibufp)
342				ibufp++;
343			break;
344		case '\'':
345			MUST_BE_FIRST();
346			ibufp++;
347			if ((addr = get_marked_node_addr(*ibufp++)) < 0)
348				return ERR;
349			break;
350		case '%':
351		case ',':
352		case ';':
353			if (first) {
354				ibufp++;
355				addr_cnt++;
356				second_addr = (c == ';') ? current_addr : 1;
357				addr = addr_last;
358				break;
359			}
360			/* FALLTHROUGH */
361		default:
362			if (ibufp == hd)
363				return EOF;
364			else if (addr < 0 || addr_last < addr) {
365				errmsg = "invalid address";
366				return ERR;
367			} else
368				return addr;
369		}
370	/* NOTREACHED */
371}
372
373
374#ifdef BACKWARDS
375/* GET_THIRD_ADDR: get a legal address from the command buffer */
376#define GET_THIRD_ADDR(addr) \
377{ \
378	long ol1, ol2; \
379\
380	ol1 = first_addr, ol2 = second_addr; \
381	if (extract_addr_range() < 0) \
382		return ERR; \
383	else if (addr_cnt == 0) { \
384		errmsg = "destination expected"; \
385		return ERR; \
386	} else if (second_addr < 0 || addr_last < second_addr) { \
387		errmsg = "invalid address"; \
388		return ERR; \
389	} \
390	addr = second_addr; \
391	first_addr = ol1, second_addr = ol2; \
392}
393#else	/* BACKWARDS */
394/* GET_THIRD_ADDR: get a legal address from the command buffer */
395#define GET_THIRD_ADDR(addr) \
396{ \
397	long ol1, ol2; \
398\
399	ol1 = first_addr, ol2 = second_addr; \
400	if (extract_addr_range() < 0) \
401		return ERR; \
402	if (second_addr < 0 || addr_last < second_addr) { \
403		errmsg = "invalid address"; \
404		return ERR; \
405	} \
406	addr = second_addr; \
407	first_addr = ol1, second_addr = ol2; \
408}
409#endif
410
411
412/* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
413#define GET_COMMAND_SUFFIX() { \
414	int done = 0; \
415	do { \
416		switch(*ibufp) { \
417		case 'p': \
418			gflag |= GPR, ibufp++; \
419			break; \
420		case 'l': \
421			gflag |= GLS, ibufp++; \
422			break; \
423		case 'n': \
424			gflag |= GNP, ibufp++; \
425			break; \
426		default: \
427			done++; \
428		} \
429	} while (!done); \
430	if (*ibufp++ != '\n') { \
431		errmsg = "invalid command suffix"; \
432		return ERR; \
433	} \
434}
435
436
437/* sflags */
438#define SGG 001		/* complement previous global substitute suffix */
439#define SGP 002		/* complement previous print suffix */
440#define SGR 004		/* use last regex instead of last pat */
441#define SGF 010		/* repeat last substitution */
442
443int patlock = 0;	/* if set, pattern not freed by get_compiled_pattern() */
444
445long rows = 22;		/* scroll length: ws_row - 2 */
446
447/* exec_command: execute the next command in command buffer; return print
448   request, if any */
449int
450exec_command(void)
451{
452	static pattern_t *pat = NULL;
453	static int sgflag = 0;
454	static long sgnum = 0;
455
456	pattern_t *tpat;
457	char *fnp;
458	int gflag = 0;
459	int sflags = 0;
460	long addr = 0;
461	int n = 0;
462	int c;
463
464	SKIP_BLANKS();
465	switch(c = *ibufp++) {
466	case 'a':
467		GET_COMMAND_SUFFIX();
468		if (!isglobal) clear_undo_stack();
469		if (append_lines(second_addr) < 0)
470			return ERR;
471		break;
472	case 'c':
473		if (check_addr_range(current_addr, current_addr) < 0)
474			return ERR;
475		GET_COMMAND_SUFFIX();
476		if (!isglobal) clear_undo_stack();
477		if (delete_lines(first_addr, second_addr) < 0 ||
478		    append_lines(current_addr) < 0)
479			return ERR;
480		break;
481	case 'd':
482		if (check_addr_range(current_addr, current_addr) < 0)
483			return ERR;
484		GET_COMMAND_SUFFIX();
485		if (!isglobal) clear_undo_stack();
486		if (delete_lines(first_addr, second_addr) < 0)
487			return ERR;
488		else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
489			current_addr = addr;
490		break;
491	case 'e':
492		if (modified && !scripted)
493			return EMOD;
494		/* FALLTHROUGH */
495	case 'E':
496		if (addr_cnt > 0) {
497			errmsg = "unexpected address";
498			return ERR;
499		} else if (!isspace((unsigned char)*ibufp)) {
500			errmsg = "unexpected command suffix";
501			return ERR;
502		} else if ((fnp = get_filename()) == NULL)
503			return ERR;
504		GET_COMMAND_SUFFIX();
505		if (delete_lines(1, addr_last) < 0)
506			return ERR;
507		clear_undo_stack();
508		if (close_sbuf() < 0)
509			return ERR;
510		else if (open_sbuf() < 0)
511			return FATAL;
512		if (*fnp && *fnp != '!') strcpy(old_filename, fnp);
513#ifdef BACKWARDS
514		if (*fnp == '\0' && *old_filename == '\0') {
515			errmsg = "no current filename";
516			return ERR;
517		}
518#endif
519		if (read_file(*fnp ? fnp : old_filename, 0) < 0)
520			return ERR;
521		clear_undo_stack();
522		modified = 0;
523		u_current_addr = u_addr_last = -1;
524		break;
525	case 'f':
526		if (addr_cnt > 0) {
527			errmsg = "unexpected address";
528			return ERR;
529		} else if (!isspace((unsigned char)*ibufp)) {
530			errmsg = "unexpected command suffix";
531			return ERR;
532		} else if ((fnp = get_filename()) == NULL)
533			return ERR;
534		else if (*fnp == '!') {
535			errmsg = "invalid redirection";
536			return ERR;
537		}
538		GET_COMMAND_SUFFIX();
539		if (*fnp) strcpy(old_filename, fnp);
540		printf("%s\n", strip_escapes(old_filename));
541		break;
542	case 'g':
543	case 'v':
544	case 'G':
545	case 'V':
546		if (isglobal) {
547			errmsg = "cannot nest global commands";
548			return ERR;
549		} else if (check_addr_range(1, addr_last) < 0)
550			return ERR;
551		else if (build_active_list(c == 'g' || c == 'G') < 0)
552			return ERR;
553		else if ((n = (c == 'G' || c == 'V')))
554			GET_COMMAND_SUFFIX();
555		isglobal++;
556		if (exec_global(n, gflag) < 0)
557			return ERR;
558		break;
559	case 'h':
560		if (addr_cnt > 0) {
561			errmsg = "unexpected address";
562			return ERR;
563		}
564		GET_COMMAND_SUFFIX();
565		if (*errmsg) fprintf(stderr, "%s\n", errmsg);
566		break;
567	case 'H':
568		if (addr_cnt > 0) {
569			errmsg = "unexpected address";
570			return ERR;
571		}
572		GET_COMMAND_SUFFIX();
573		if ((garrulous = 1 - garrulous) && *errmsg)
574			fprintf(stderr, "%s\n", errmsg);
575		break;
576	case 'i':
577		if (second_addr == 0) {
578			errmsg = "invalid address";
579			return ERR;
580		}
581		GET_COMMAND_SUFFIX();
582		if (!isglobal) clear_undo_stack();
583		if (append_lines(second_addr - 1) < 0)
584			return ERR;
585		break;
586	case 'j':
587		if (check_addr_range(current_addr, current_addr + 1) < 0)
588			return ERR;
589		GET_COMMAND_SUFFIX();
590		if (!isglobal) clear_undo_stack();
591		if (first_addr != second_addr &&
592		    join_lines(first_addr, second_addr) < 0)
593			return ERR;
594		break;
595	case 'k':
596		c = *ibufp++;
597		if (second_addr == 0) {
598			errmsg = "invalid address";
599			return ERR;
600		}
601		GET_COMMAND_SUFFIX();
602		if (mark_line_node(get_addressed_line_node(second_addr), c) < 0)
603			return ERR;
604		break;
605	case 'l':
606		if (check_addr_range(current_addr, current_addr) < 0)
607			return ERR;
608		GET_COMMAND_SUFFIX();
609		if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
610			return ERR;
611		gflag = 0;
612		break;
613	case 'm':
614		if (check_addr_range(current_addr, current_addr) < 0)
615			return ERR;
616		GET_THIRD_ADDR(addr);
617		if (first_addr <= addr && addr < second_addr) {
618			errmsg = "invalid destination";
619			return ERR;
620		}
621		GET_COMMAND_SUFFIX();
622		if (!isglobal) clear_undo_stack();
623		if (move_lines(addr) < 0)
624			return ERR;
625		break;
626	case 'n':
627		if (check_addr_range(current_addr, current_addr) < 0)
628			return ERR;
629		GET_COMMAND_SUFFIX();
630		if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
631			return ERR;
632		gflag = 0;
633		break;
634	case 'p':
635		if (check_addr_range(current_addr, current_addr) < 0)
636			return ERR;
637		GET_COMMAND_SUFFIX();
638		if (display_lines(first_addr, second_addr, gflag | GPR) < 0)
639			return ERR;
640		gflag = 0;
641		break;
642	case 'P':
643		if (addr_cnt > 0) {
644			errmsg = "unexpected address";
645			return ERR;
646		}
647		GET_COMMAND_SUFFIX();
648		prompt = prompt ? NULL : optarg ? optarg : dps;
649		break;
650	case 'q':
651	case 'Q':
652		if (addr_cnt > 0) {
653			errmsg = "unexpected address";
654			return ERR;
655		}
656		GET_COMMAND_SUFFIX();
657		gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
658		break;
659	case 'r':
660		if (!isspace((unsigned char)*ibufp)) {
661			errmsg = "unexpected command suffix";
662			return ERR;
663		} else if (addr_cnt == 0)
664			second_addr = addr_last;
665		if ((fnp = get_filename()) == NULL)
666			return ERR;
667		GET_COMMAND_SUFFIX();
668		if (!isglobal) clear_undo_stack();
669		if (*old_filename == '\0' && *fnp != '!')
670			strcpy(old_filename, fnp);
671#ifdef BACKWARDS
672		if (*fnp == '\0' && *old_filename == '\0') {
673			errmsg = "no current filename";
674			return ERR;
675		}
676#endif
677		if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
678			return ERR;
679		else if (addr && addr != addr_last)
680			modified = 1;
681		break;
682	case 's':
683		do {
684			switch(*ibufp) {
685			case '\n':
686				sflags |=SGF;
687				break;
688			case 'g':
689				sflags |= SGG;
690				ibufp++;
691				break;
692			case 'p':
693				sflags |= SGP;
694				ibufp++;
695				break;
696			case 'r':
697				sflags |= SGR;
698				ibufp++;
699				break;
700			case '0': case '1': case '2': case '3': case '4':
701			case '5': case '6': case '7': case '8': case '9':
702				STRTOL(sgnum, ibufp);
703				sflags |= SGF;
704				sgflag &= ~GSG;		/* override GSG */
705				break;
706			default:
707				if (sflags) {
708					errmsg = "invalid command suffix";
709					return ERR;
710				}
711			}
712		} while (sflags && *ibufp != '\n');
713		if (sflags && !pat) {
714			errmsg = "no previous substitution";
715			return ERR;
716		} else if (sflags & SGG)
717			sgnum = 0;		/* override numeric arg */
718		if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
719			errmsg = "invalid pattern delimiter";
720			return ERR;
721		}
722		tpat = pat;
723		SPL1();
724		if ((!sflags || (sflags & SGR)) &&
725		    (tpat = get_compiled_pattern()) == NULL) {
726		 	SPL0();
727			return ERR;
728		} else if (tpat != pat) {
729			if (pat) {
730				regfree(pat);
731				free(pat);
732			}
733			pat = tpat;
734			patlock = 1;		/* reserve pattern */
735		}
736		SPL0();
737		if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
738			return ERR;
739		else if (isglobal)
740			sgflag |= GLB;
741		else
742			sgflag &= ~GLB;
743		if (sflags & SGG)
744			sgflag ^= GSG;
745		if (sflags & SGP)
746			sgflag ^= GPR, sgflag &= ~(GLS | GNP);
747		do {
748			switch(*ibufp) {
749			case 'p':
750				sgflag |= GPR, ibufp++;
751				break;
752			case 'l':
753				sgflag |= GLS, ibufp++;
754				break;
755			case 'n':
756				sgflag |= GNP, ibufp++;
757				break;
758			default:
759				n++;
760			}
761		} while (!n);
762		if (check_addr_range(current_addr, current_addr) < 0)
763			return ERR;
764		GET_COMMAND_SUFFIX();
765		if (!isglobal) clear_undo_stack();
766		if (search_and_replace(pat, sgflag, sgnum) < 0)
767			return ERR;
768		break;
769	case 't':
770		if (check_addr_range(current_addr, current_addr) < 0)
771			return ERR;
772		GET_THIRD_ADDR(addr);
773		GET_COMMAND_SUFFIX();
774		if (!isglobal) clear_undo_stack();
775		if (copy_lines(addr) < 0)
776			return ERR;
777		break;
778	case 'u':
779		if (addr_cnt > 0) {
780			errmsg = "unexpected address";
781			return ERR;
782		}
783		GET_COMMAND_SUFFIX();
784		if (pop_undo_stack() < 0)
785			return ERR;
786		break;
787	case 'w':
788	case 'W':
789		if ((n = *ibufp) == 'q' || n == 'Q') {
790			gflag = EOF;
791			ibufp++;
792		}
793		if (!isspace((unsigned char)*ibufp)) {
794			errmsg = "unexpected command suffix";
795			return ERR;
796		} else if ((fnp = get_filename()) == NULL)
797			return ERR;
798		if (addr_cnt == 0 && !addr_last)
799			first_addr = second_addr = 0;
800		else if (check_addr_range(1, addr_last) < 0)
801			return ERR;
802		GET_COMMAND_SUFFIX();
803		if (*old_filename == '\0' && *fnp != '!')
804			strcpy(old_filename, fnp);
805#ifdef BACKWARDS
806		if (*fnp == '\0' && *old_filename == '\0') {
807			errmsg = "no current filename";
808			return ERR;
809		}
810#endif
811		if ((addr = write_file(*fnp ? fnp : old_filename,
812		    (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
813			return ERR;
814		else if (addr == addr_last)
815			modified = 0;
816		else if (modified && !scripted && n == 'q')
817			gflag = EMOD;
818		break;
819	case 'x':
820		if (addr_cnt > 0) {
821			errmsg = "unexpected address";
822			return ERR;
823		}
824		GET_COMMAND_SUFFIX();
825#ifdef DES
826		des = get_keyword();
827#else
828		errmsg = "crypt unavailable";
829		return ERR;
830#endif
831		break;
832	case 'z':
833#ifdef BACKWARDS
834		if (check_addr_range(first_addr = 1, current_addr + 1) < 0)
835#else
836		if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0)
837#endif
838			return ERR;
839		else if ('0' < *ibufp && *ibufp <= '9')
840			STRTOL(rows, ibufp);
841		GET_COMMAND_SUFFIX();
842		if (display_lines(second_addr, min(addr_last,
843		    second_addr + rows), gflag) < 0)
844			return ERR;
845		gflag = 0;
846		break;
847	case '=':
848		GET_COMMAND_SUFFIX();
849		printf("%ld\n", addr_cnt ? second_addr : addr_last);
850		break;
851	case '!':
852		if (addr_cnt > 0) {
853			errmsg = "unexpected address";
854			return ERR;
855		} else if ((sflags = get_shell_command()) < 0)
856			return ERR;
857		GET_COMMAND_SUFFIX();
858		if (sflags) printf("%s\n", shcmd + 1);
859		system(shcmd + 1);
860		if (!scripted) printf("!\n");
861		break;
862	case '\n':
863#ifdef BACKWARDS
864		if (check_addr_range(first_addr = 1, current_addr + 1) < 0
865#else
866		if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0
867#endif
868		 || display_lines(second_addr, second_addr, 0) < 0)
869			return ERR;
870		break;
871	default:
872		errmsg = "unknown command";
873		return ERR;
874	}
875	return gflag;
876}
877
878
879/* check_addr_range: return status of address range check */
880int
881check_addr_range(long n, long m)
882{
883	if (addr_cnt == 0) {
884		first_addr = n;
885		second_addr = m;
886	}
887	if (first_addr > second_addr || 1 > first_addr ||
888	    second_addr > addr_last) {
889		errmsg = "invalid address";
890		return ERR;
891	}
892	return 0;
893}
894
895
896/* get_matching_node_addr: return the address of the next line matching a
897   pattern in a given direction.  wrap around begin/end of editor buffer if
898   necessary */
899long
900get_matching_node_addr(pattern_t *pat, int dir)
901{
902	char *s;
903	long n = current_addr;
904	line_t *lp;
905
906	if (!pat) return ERR;
907	do {
908	       if ((n = dir ? INC_MOD(n, addr_last) : DEC_MOD(n, addr_last))) {
909			lp = get_addressed_line_node(n);
910			if ((s = get_sbuf_line(lp)) == NULL)
911				return ERR;
912			if (isbinary)
913				NUL_TO_NEWLINE(s, lp->len);
914			if (!regexec(pat, s, 0, NULL, 0))
915				return n;
916	       }
917	} while (n != current_addr);
918	errmsg = "no match";
919	return  ERR;
920}
921
922
923/* get_filename: return pointer to copy of filename in the command buffer */
924char *
925get_filename(void)
926{
927	static char *file = NULL;
928	static int filesz = 0;
929
930	int n;
931
932	if (*ibufp != '\n') {
933		SKIP_BLANKS();
934		if (*ibufp == '\n') {
935			errmsg = "invalid filename";
936			return NULL;
937		} else if ((ibufp = get_extended_line(&n, 1)) == NULL)
938			return NULL;
939		else if (*ibufp == '!') {
940			ibufp++;
941			if ((n = get_shell_command()) < 0)
942				return NULL;
943			if (n)
944				printf("%s\n", shcmd + 1);
945			return shcmd;
946		} else if (n > PATH_MAX - 1) {
947			errmsg = "filename too long";
948			return  NULL;
949		}
950	}
951#ifndef BACKWARDS
952	else if (*old_filename == '\0') {
953		errmsg = "no current filename";
954		return  NULL;
955	}
956#endif
957	REALLOC(file, filesz, PATH_MAX, NULL);
958	for (n = 0; *ibufp != '\n';)
959		file[n++] = *ibufp++;
960	file[n] = '\0';
961	return is_legal_filename(file) ? file : NULL;
962}
963
964
965/* get_shell_command: read a shell command from stdin; return substitution
966   status */
967int
968get_shell_command(void)
969{
970	static char *buf = NULL;
971	static int n = 0;
972
973	char *s;			/* substitution char pointer */
974	int i = 0;
975	int j = 0;
976
977	if (red) {
978		errmsg = "shell access restricted";
979		return ERR;
980	} else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
981		return ERR;
982	REALLOC(buf, n, j + 1, ERR);
983	buf[i++] = '!';			/* prefix command w/ bang */
984	while (*ibufp != '\n')
985		switch (*ibufp) {
986		default:
987			REALLOC(buf, n, i + 2, ERR);
988			buf[i++] = *ibufp;
989			if (*ibufp++ == '\\')
990				buf[i++] = *ibufp++;
991			break;
992		case '!':
993			if (s != ibufp) {
994				REALLOC(buf, n, i + 1, ERR);
995				buf[i++] = *ibufp++;
996			}
997#ifdef BACKWARDS
998			else if (shcmd == NULL || *(shcmd + 1) == '\0')
999#else
1000			else if (shcmd == NULL)
1001#endif
1002			{
1003				errmsg = "no previous command";
1004				return ERR;
1005			} else {
1006				REALLOC(buf, n, i + shcmdi, ERR);
1007				for (s = shcmd + 1; s < shcmd + shcmdi;)
1008					buf[i++] = *s++;
1009				s = ibufp++;
1010			}
1011			break;
1012		case '%':
1013			if (*old_filename  == '\0') {
1014				errmsg = "no current filename";
1015				return ERR;
1016			}
1017			j = strlen(s = strip_escapes(old_filename));
1018			REALLOC(buf, n, i + j, ERR);
1019			while (j--)
1020				buf[i++] = *s++;
1021			s = ibufp++;
1022			break;
1023		}
1024	REALLOC(shcmd, shcmdsz, i + 1, ERR);
1025	memcpy(shcmd, buf, i);
1026	shcmd[shcmdi = i] = '\0';
1027	return *s == '!' || *s == '%';
1028}
1029
1030
1031/* append_lines: insert text from stdin to after line n; stop when either a
1032   single period is read or EOF; return status */
1033int
1034append_lines(long n)
1035{
1036	int l;
1037	const char *lp = ibuf;
1038	const char *eot;
1039	undo_t *up = NULL;
1040
1041	for (current_addr = n;;) {
1042		if (!isglobal) {
1043			if ((l = get_tty_line()) < 0)
1044				return ERR;
1045			else if (l == 0 || ibuf[l - 1] != '\n') {
1046				clearerr(stdin);
1047				return  l ? EOF : 0;
1048			}
1049			lp = ibuf;
1050		} else if (*(lp = ibufp) == '\0')
1051			return 0;
1052		else {
1053			while (*ibufp++ != '\n')
1054				;
1055			l = ibufp - lp;
1056		}
1057		if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1058			return 0;
1059		}
1060		eot = lp + l;
1061		SPL1();
1062		do {
1063			if ((lp = put_sbuf_line(lp)) == NULL) {
1064				SPL0();
1065				return ERR;
1066			} else if (up)
1067				up->t = get_addressed_line_node(current_addr);
1068			else if ((up = push_undo_stack(UADD, current_addr,
1069			    current_addr)) == NULL) {
1070				SPL0();
1071				return ERR;
1072			}
1073		} while (lp != eot);
1074		modified = 1;
1075		SPL0();
1076	}
1077	/* NOTREACHED */
1078}
1079
1080
1081/* join_lines: replace a range of lines with the joined text of those lines */
1082int
1083join_lines(long from, long to)
1084{
1085	static char *buf = NULL;
1086	static int n;
1087
1088	char *s;
1089	int size = 0;
1090	line_t *bp, *ep;
1091
1092	ep = get_addressed_line_node(INC_MOD(to, addr_last));
1093	bp = get_addressed_line_node(from);
1094	for (; bp != ep; bp = bp->q_forw) {
1095		if ((s = get_sbuf_line(bp)) == NULL)
1096			return ERR;
1097		REALLOC(buf, n, size + bp->len, ERR);
1098		memcpy(buf + size, s, bp->len);
1099		size += bp->len;
1100	}
1101	REALLOC(buf, n, size + 2, ERR);
1102	memcpy(buf + size, "\n", 2);
1103	if (delete_lines(from, to) < 0)
1104		return ERR;
1105	current_addr = from - 1;
1106	SPL1();
1107	if (put_sbuf_line(buf) == NULL ||
1108	    push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1109		SPL0();
1110		return ERR;
1111	}
1112	modified = 1;
1113	SPL0();
1114	return 0;
1115}
1116
1117
1118/* move_lines: move a range of lines */
1119int
1120move_lines(long addr)
1121{
1122	line_t *b1, *a1, *b2, *a2;
1123	long n = INC_MOD(second_addr, addr_last);
1124	long p = first_addr - 1;
1125	int done = (addr == first_addr - 1 || addr == second_addr);
1126
1127	SPL1();
1128	if (done) {
1129		a2 = get_addressed_line_node(n);
1130		b2 = get_addressed_line_node(p);
1131		current_addr = second_addr;
1132	} else if (push_undo_stack(UMOV, p, n) == NULL ||
1133	    push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1134		SPL0();
1135		return ERR;
1136	} else {
1137		a1 = get_addressed_line_node(n);
1138		if (addr < first_addr) {
1139			b1 = get_addressed_line_node(p);
1140			b2 = get_addressed_line_node(addr);
1141					/* this get_addressed_line_node last! */
1142		} else {
1143			b2 = get_addressed_line_node(addr);
1144			b1 = get_addressed_line_node(p);
1145					/* this get_addressed_line_node last! */
1146		}
1147		a2 = b2->q_forw;
1148		REQUE(b2, b1->q_forw);
1149		REQUE(a1->q_back, a2);
1150		REQUE(b1, a1);
1151		current_addr = addr + ((addr < first_addr) ?
1152		    second_addr - first_addr + 1 : 0);
1153	}
1154	if (isglobal)
1155		unset_active_nodes(b2->q_forw, a2);
1156	modified = 1;
1157	SPL0();
1158	return 0;
1159}
1160
1161
1162/* copy_lines: copy a range of lines; return status */
1163int
1164copy_lines(long addr)
1165{
1166	line_t *lp, *np = get_addressed_line_node(first_addr);
1167	undo_t *up = NULL;
1168	long n = second_addr - first_addr + 1;
1169	long m = 0;
1170
1171	current_addr = addr;
1172	if (first_addr <= addr && addr < second_addr) {
1173		n =  addr - first_addr + 1;
1174		m = second_addr - addr;
1175	}
1176	for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1177		for (; n-- > 0; np = np->q_forw) {
1178			SPL1();
1179			if ((lp = dup_line_node(np)) == NULL) {
1180				SPL0();
1181				return ERR;
1182			}
1183			add_line_node(lp);
1184			if (up)
1185				up->t = lp;
1186			else if ((up = push_undo_stack(UADD, current_addr,
1187			    current_addr)) == NULL) {
1188				SPL0();
1189				return ERR;
1190			}
1191			modified = 1;
1192			SPL0();
1193		}
1194	return 0;
1195}
1196
1197
1198/* delete_lines: delete a range of lines */
1199int
1200delete_lines(long from, long to)
1201{
1202	line_t *n, *p;
1203
1204	SPL1();
1205	if (push_undo_stack(UDEL, from, to) == NULL) {
1206		SPL0();
1207		return ERR;
1208	}
1209	n = get_addressed_line_node(INC_MOD(to, addr_last));
1210	p = get_addressed_line_node(from - 1);
1211					/* this get_addressed_line_node last! */
1212	if (isglobal)
1213		unset_active_nodes(p->q_forw, n);
1214	REQUE(p, n);
1215	addr_last -= to - from + 1;
1216	current_addr = from - 1;
1217	modified = 1;
1218	SPL0();
1219	return 0;
1220}
1221
1222
1223/* display_lines: print a range of lines to stdout */
1224int
1225display_lines(long from, long to, int gflag)
1226{
1227	line_t *bp;
1228	line_t *ep;
1229	char *s;
1230
1231	if (!from) {
1232		errmsg = "invalid address";
1233		return ERR;
1234	}
1235	ep = get_addressed_line_node(INC_MOD(to, addr_last));
1236	bp = get_addressed_line_node(from);
1237	for (; bp != ep; bp = bp->q_forw) {
1238		if ((s = get_sbuf_line(bp)) == NULL)
1239			return ERR;
1240		if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1241			return ERR;
1242	}
1243	return 0;
1244}
1245
1246
1247#define MAXMARK 26			/* max number of marks */
1248
1249line_t	*mark[MAXMARK];			/* line markers */
1250int markno;				/* line marker count */
1251
1252/* mark_line_node: set a line node mark */
1253int
1254mark_line_node(line_t *lp, int n)
1255{
1256	if (!islower((unsigned char)n)) {
1257		errmsg = "invalid mark character";
1258		return ERR;
1259	} else if (mark[n - 'a'] == NULL)
1260		markno++;
1261	mark[n - 'a'] = lp;
1262	return 0;
1263}
1264
1265
1266/* get_marked_node_addr: return address of a marked line */
1267long
1268get_marked_node_addr(int n)
1269{
1270	if (!islower((unsigned char)n)) {
1271		errmsg = "invalid mark character";
1272		return ERR;
1273	}
1274	return get_line_node_addr(mark[n - 'a']);
1275}
1276
1277
1278/* unmark_line_node: clear line node mark */
1279void
1280unmark_line_node(line_t *lp)
1281{
1282	int i;
1283
1284	for (i = 0; markno && i < MAXMARK; i++)
1285		if (mark[i] == lp) {
1286			mark[i] = NULL;
1287			markno--;
1288		}
1289}
1290
1291
1292/* dup_line_node: return a pointer to a copy of a line node */
1293line_t *
1294dup_line_node(line_t *lp)
1295{
1296	line_t *np;
1297
1298	if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1299		fprintf(stderr, "%s\n", strerror(errno));
1300		errmsg = "out of memory";
1301		return NULL;
1302	}
1303	np->seek = lp->seek;
1304	np->len = lp->len;
1305	return np;
1306}
1307
1308
1309/* has_trailing_escape:  return the parity of escapes preceding a character
1310   in a string */
1311int
1312has_trailing_escape(char *s, char *t)
1313{
1314    return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1315}
1316
1317
1318/* strip_escapes: return copy of escaped string of at most length PATH_MAX */
1319char *
1320strip_escapes(char *s)
1321{
1322	static char *file = NULL;
1323	static int filesz = 0;
1324
1325	int i = 0;
1326
1327	REALLOC(file, filesz, PATH_MAX, NULL);
1328	while (i < filesz - 1	/* Worry about a possible trailing escape */
1329	       && (file[i++] = (*s == '\\') ? *++s : *s))
1330		s++;
1331	return file;
1332}
1333
1334
1335void
1336signal_hup(int signo)
1337{
1338	if (mutex)
1339		sigflags |= (1 << (signo - 1));
1340	else
1341		handle_hup(signo);
1342}
1343
1344
1345void
1346signal_int(int signo)
1347{
1348	if (mutex)
1349		sigflags |= (1 << (signo - 1));
1350	else
1351		handle_int(signo);
1352}
1353
1354
1355void
1356handle_hup(int signo)
1357{
1358	char *hup = NULL;		/* hup filename */
1359	char *s;
1360	char ed_hup[] = "ed.hup";
1361	int n;
1362
1363	if (!sigactive)
1364		quit(1);
1365	sigflags &= ~(1 << (signo - 1));
1366	if (addr_last && write_file(ed_hup, "w", 1, addr_last) < 0 &&
1367	    (s = getenv("HOME")) != NULL &&
1368	    (n = strlen(s)) + 8 <= PATH_MAX &&	/* "ed.hup" + '/' */
1369	    (hup = (char *) malloc(n + 10)) != NULL) {
1370		strcpy(hup, s);
1371		if (hup[n - 1] != '/')
1372			hup[n] = '/', hup[n+1] = '\0';
1373		strcat(hup, "ed.hup");
1374		write_file(hup, "w", 1, addr_last);
1375	}
1376	quit(2);
1377}
1378
1379
1380void
1381handle_int(int signo)
1382{
1383	if (!sigactive)
1384		quit(1);
1385	sigflags &= ~(1 << (signo - 1));
1386#ifdef _POSIX_SOURCE
1387	siglongjmp(env, -1);
1388#else
1389	longjmp(env, -1);
1390#endif
1391}
1392
1393
1394int cols = 72;				/* wrap column */
1395
1396void
1397handle_winch(int signo)
1398{
1399	int save_errno = errno;
1400
1401	struct winsize ws;		/* window size structure */
1402
1403	sigflags &= ~(1 << (signo - 1));
1404	if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1405		if (ws.ws_row > 2) rows = ws.ws_row - 2;
1406		if (ws.ws_col > 8) cols = ws.ws_col - 8;
1407	}
1408	errno = save_errno;
1409}
1410
1411
1412/* is_legal_filename: return a legal filename */
1413int
1414is_legal_filename(char *s)
1415{
1416	if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1417		errmsg = "shell access restricted";
1418		return 0;
1419	}
1420	return 1;
1421}
1422