main.c revision 90109 
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#ifndef lint
36static const char rcsid[] =
37  "$FreeBSD: head/bin/ed/main.c 90109 2002-02-02 06:36:49Z imp $";
38#endif /* not lint */
39
40/*
41 * CREDITS
42 *
43 *	This program is based on the editor algorithm described in
44 *	Brian W. Kernighan and P. J. Plauger's book "Software Tools
45 *	in Pascal," Addison-Wesley, 1981.
46 *
47 *	The buffering algorithm is attributed to Rodney Ruddock of
48 *	the University of Guelph, Guelph, Ontario.
49 *
50 *	The cbc.c encryption code is adapted from
51 *	the bdes program by Matt Bishop of Dartmouth College,
52 *	Hanover, NH.
53 *
54 */
55
56#include <sys/types.h>
57
58#include <sys/ioctl.h>
59#include <sys/wait.h>
60#include <ctype.h>
61#include <locale.h>
62#include <pwd.h>
63#include <setjmp.h>
64
65#include "ed.h"
66
67
68#ifdef _POSIX_SOURCE
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			/* FALL THROUGH */
361		default:
362			if (ibufp == hd)
363				return EOF;
364			else if (addr < 0 || addr_last < addr) {
365				errmsg = "invalid address";
366				return ERR;
367			} else
368				return addr;
369		}
370	/* NOTREACHED */
371}
372
373
374#ifdef BACKWARDS
375/* GET_THIRD_ADDR: get a legal address from the command buffer */
376#define GET_THIRD_ADDR(addr) \
377{ \
378	long ol1, ol2; \
379\
380	ol1 = first_addr, ol2 = second_addr; \
381	if (extract_addr_range() < 0) \
382		return ERR; \
383	else if (addr_cnt == 0) { \
384		errmsg = "destination expected"; \
385		return ERR; \
386	} else if (second_addr < 0 || addr_last < second_addr) { \
387		errmsg = "invalid address"; \
388		return ERR; \
389	} \
390	addr = second_addr; \
391	first_addr = ol1, second_addr = ol2; \
392}
393#else	/* BACKWARDS */
394/* GET_THIRD_ADDR: get a legal address from the command buffer */
395#define GET_THIRD_ADDR(addr) \
396{ \
397	long ol1, ol2; \
398\
399	ol1 = first_addr, ol2 = second_addr; \
400	if (extract_addr_range() < 0) \
401		return ERR; \
402	if (second_addr < 0 || addr_last < second_addr) { \
403		errmsg = "invalid address"; \
404		return ERR; \
405	} \
406	addr = second_addr; \
407	first_addr = ol1, second_addr = ol2; \
408}
409#endif
410
411
412/* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
413#define GET_COMMAND_SUFFIX() { \
414	int done = 0; \
415	do { \
416		switch(*ibufp) { \
417		case 'p': \
418			gflag |= GPR, ibufp++; \
419			break; \
420		case 'l': \
421			gflag |= GLS, ibufp++; \
422			break; \
423		case 'n': \
424			gflag |= GNP, ibufp++; \
425			break; \
426		default: \
427			done++; \
428		} \
429	} while (!done); \
430	if (*ibufp++ != '\n') { \
431		errmsg = "invalid command suffix"; \
432		return ERR; \
433	} \
434}
435
436
437/* sflags */
438#define SGG 001		/* complement previous global substitute suffix */
439#define SGP 002		/* complement previous print suffix */
440#define SGR 004		/* use last regex instead of last pat */
441#define SGF 010		/* repeat last substitution */
442
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	extern long u_current_addr;
453	extern long u_addr_last;
454
455	static pattern_t *pat = NULL;
456	static int sgflag = 0;
457	static long sgnum = 0;
458
459	pattern_t *tpat;
460	char *fnp;
461	int gflag = 0;
462	int sflags = 0;
463	long addr = 0;
464	int n = 0;
465	int c;
466
467	SKIP_BLANKS();
468	switch(c = *ibufp++) {
469	case 'a':
470		GET_COMMAND_SUFFIX();
471		if (!isglobal) clear_undo_stack();
472		if (append_lines(second_addr) < 0)
473			return ERR;
474		break;
475	case 'c':
476		if (check_addr_range(current_addr, current_addr) < 0)
477			return ERR;
478		GET_COMMAND_SUFFIX();
479		if (!isglobal) clear_undo_stack();
480		if (delete_lines(first_addr, second_addr) < 0 ||
481		    append_lines(current_addr) < 0)
482			return ERR;
483		break;
484	case 'd':
485		if (check_addr_range(current_addr, current_addr) < 0)
486			return ERR;
487		GET_COMMAND_SUFFIX();
488		if (!isglobal) clear_undo_stack();
489		if (delete_lines(first_addr, second_addr) < 0)
490			return ERR;
491		else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
492			current_addr = addr;
493		break;
494	case 'e':
495		if (modified && !scripted)
496			return EMOD;
497		/* fall through */
498	case 'E':
499		if (addr_cnt > 0) {
500			errmsg = "unexpected address";
501			return ERR;
502		} else if (!isspace((unsigned char)*ibufp)) {
503			errmsg = "unexpected command suffix";
504			return ERR;
505		} else if ((fnp = get_filename()) == NULL)
506			return ERR;
507		GET_COMMAND_SUFFIX();
508		if (delete_lines(1, addr_last) < 0)
509			return ERR;
510		clear_undo_stack();
511		if (close_sbuf() < 0)
512			return ERR;
513		else if (open_sbuf() < 0)
514			return FATAL;
515		if (*fnp && *fnp != '!') strcpy(old_filename, fnp);
516#ifdef BACKWARDS
517		if (*fnp == '\0' && *old_filename == '\0') {
518			errmsg = "no current filename";
519			return ERR;
520		}
521#endif
522		if (read_file(*fnp ? fnp : old_filename, 0) < 0)
523			return ERR;
524		clear_undo_stack();
525		modified = 0;
526		u_current_addr = u_addr_last = -1;
527		break;
528	case 'f':
529		if (addr_cnt > 0) {
530			errmsg = "unexpected address";
531			return ERR;
532		} else if (!isspace((unsigned char)*ibufp)) {
533			errmsg = "unexpected command suffix";
534			return ERR;
535		} else if ((fnp = get_filename()) == NULL)
536			return ERR;
537		else if (*fnp == '!') {
538			errmsg = "invalid redirection";
539			return ERR;
540		}
541		GET_COMMAND_SUFFIX();
542		if (*fnp) strcpy(old_filename, fnp);
543		printf("%s\n", strip_escapes(old_filename));
544		break;
545	case 'g':
546	case 'v':
547	case 'G':
548	case 'V':
549		if (isglobal) {
550			errmsg = "cannot nest global commands";
551			return ERR;
552		} else if (check_addr_range(1, addr_last) < 0)
553			return ERR;
554		else if (build_active_list(c == 'g' || c == 'G') < 0)
555			return ERR;
556		else if ((n = (c == 'G' || c == 'V')))
557			GET_COMMAND_SUFFIX();
558		isglobal++;
559		if (exec_global(n, gflag) < 0)
560			return ERR;
561		break;
562	case 'h':
563		if (addr_cnt > 0) {
564			errmsg = "unexpected address";
565			return ERR;
566		}
567		GET_COMMAND_SUFFIX();
568		if (*errmsg) fprintf(stderr, "%s\n", errmsg);
569		break;
570	case 'H':
571		if (addr_cnt > 0) {
572			errmsg = "unexpected address";
573			return ERR;
574		}
575		GET_COMMAND_SUFFIX();
576		if ((garrulous = 1 - garrulous) && *errmsg)
577			fprintf(stderr, "%s\n", errmsg);
578		break;
579	case 'i':
580		if (second_addr == 0) {
581			errmsg = "invalid address";
582			return ERR;
583		}
584		GET_COMMAND_SUFFIX();
585		if (!isglobal) clear_undo_stack();
586		if (append_lines(second_addr - 1) < 0)
587			return ERR;
588		break;
589	case 'j':
590		if (check_addr_range(current_addr, current_addr + 1) < 0)
591			return ERR;
592		GET_COMMAND_SUFFIX();
593		if (!isglobal) clear_undo_stack();
594		if (first_addr != second_addr &&
595		    join_lines(first_addr, second_addr) < 0)
596			return ERR;
597		break;
598	case 'k':
599		c = *ibufp++;
600		if (second_addr == 0) {
601			errmsg = "invalid address";
602			return ERR;
603		}
604		GET_COMMAND_SUFFIX();
605		if (mark_line_node(get_addressed_line_node(second_addr), c) < 0)
606			return ERR;
607		break;
608	case 'l':
609		if (check_addr_range(current_addr, current_addr) < 0)
610			return ERR;
611		GET_COMMAND_SUFFIX();
612		if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
613			return ERR;
614		gflag = 0;
615		break;
616	case 'm':
617		if (check_addr_range(current_addr, current_addr) < 0)
618			return ERR;
619		GET_THIRD_ADDR(addr);
620		if (first_addr <= addr && addr < second_addr) {
621			errmsg = "invalid destination";
622			return ERR;
623		}
624		GET_COMMAND_SUFFIX();
625		if (!isglobal) clear_undo_stack();
626		if (move_lines(addr) < 0)
627			return ERR;
628		break;
629	case 'n':
630		if (check_addr_range(current_addr, current_addr) < 0)
631			return ERR;
632		GET_COMMAND_SUFFIX();
633		if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
634			return ERR;
635		gflag = 0;
636		break;
637	case 'p':
638		if (check_addr_range(current_addr, current_addr) < 0)
639			return ERR;
640		GET_COMMAND_SUFFIX();
641		if (display_lines(first_addr, second_addr, gflag | GPR) < 0)
642			return ERR;
643		gflag = 0;
644		break;
645	case 'P':
646		if (addr_cnt > 0) {
647			errmsg = "unexpected address";
648			return ERR;
649		}
650		GET_COMMAND_SUFFIX();
651		prompt = prompt ? NULL : optarg ? optarg : dps;
652		break;
653	case 'q':
654	case 'Q':
655		if (addr_cnt > 0) {
656			errmsg = "unexpected address";
657			return ERR;
658		}
659		GET_COMMAND_SUFFIX();
660		gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
661		break;
662	case 'r':
663		if (!isspace((unsigned char)*ibufp)) {
664			errmsg = "unexpected command suffix";
665			return ERR;
666		} else if (addr_cnt == 0)
667			second_addr = addr_last;
668		if ((fnp = get_filename()) == NULL)
669			return ERR;
670		GET_COMMAND_SUFFIX();
671		if (!isglobal) clear_undo_stack();
672		if (*old_filename == '\0' && *fnp != '!')
673			strcpy(old_filename, fnp);
674#ifdef BACKWARDS
675		if (*fnp == '\0' && *old_filename == '\0') {
676			errmsg = "no current filename";
677			return ERR;
678		}
679#endif
680		if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
681			return ERR;
682		else if (addr && addr != addr_last)
683			modified = 1;
684		break;
685	case 's':
686		do {
687			switch(*ibufp) {
688			case '\n':
689				sflags |=SGF;
690				break;
691			case 'g':
692				sflags |= SGG;
693				ibufp++;
694				break;
695			case 'p':
696				sflags |= SGP;
697				ibufp++;
698				break;
699			case 'r':
700				sflags |= SGR;
701				ibufp++;
702				break;
703			case '0': case '1': case '2': case '3': case '4':
704			case '5': case '6': case '7': case '8': case '9':
705				STRTOL(sgnum, ibufp);
706				sflags |= SGF;
707				sgflag &= ~GSG;		/* override GSG */
708				break;
709			default:
710				if (sflags) {
711					errmsg = "invalid command suffix";
712					return ERR;
713				}
714			}
715		} while (sflags && *ibufp != '\n');
716		if (sflags && !pat) {
717			errmsg = "no previous substitution";
718			return ERR;
719		} else if (sflags & SGG)
720			sgnum = 0;		/* override numeric arg */
721		if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
722			errmsg = "invalid pattern delimiter";
723			return ERR;
724		}
725		tpat = pat;
726		SPL1();
727		if ((!sflags || (sflags & SGR)) &&
728		    (tpat = get_compiled_pattern()) == NULL) {
729		 	SPL0();
730			return ERR;
731		} else if (tpat != pat) {
732			if (pat) {
733				regfree(pat);
734				free(pat);
735			}
736			pat = tpat;
737			patlock = 1;		/* reserve pattern */
738		}
739		SPL0();
740		if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
741			return ERR;
742		else if (isglobal)
743			sgflag |= GLB;
744		else
745			sgflag &= ~GLB;
746		if (sflags & SGG)
747			sgflag ^= GSG;
748		if (sflags & SGP)
749			sgflag ^= GPR, sgflag &= ~(GLS | GNP);
750		do {
751			switch(*ibufp) {
752			case 'p':
753				sgflag |= GPR, ibufp++;
754				break;
755			case 'l':
756				sgflag |= GLS, ibufp++;
757				break;
758			case 'n':
759				sgflag |= GNP, ibufp++;
760				break;
761			default:
762				n++;
763			}
764		} while (!n);
765		if (check_addr_range(current_addr, current_addr) < 0)
766			return ERR;
767		GET_COMMAND_SUFFIX();
768		if (!isglobal) clear_undo_stack();
769		if (search_and_replace(pat, sgflag, sgnum) < 0)
770			return ERR;
771		break;
772	case 't':
773		if (check_addr_range(current_addr, current_addr) < 0)
774			return ERR;
775		GET_THIRD_ADDR(addr);
776		GET_COMMAND_SUFFIX();
777		if (!isglobal) clear_undo_stack();
778		if (copy_lines(addr) < 0)
779			return ERR;
780		break;
781	case 'u':
782		if (addr_cnt > 0) {
783			errmsg = "unexpected address";
784			return ERR;
785		}
786		GET_COMMAND_SUFFIX();
787		if (pop_undo_stack() < 0)
788			return ERR;
789		break;
790	case 'w':
791	case 'W':
792		if ((n = *ibufp) == 'q' || n == 'Q') {
793			gflag = EOF;
794			ibufp++;
795		}
796		if (!isspace((unsigned char)*ibufp)) {
797			errmsg = "unexpected command suffix";
798			return ERR;
799		} else if ((fnp = get_filename()) == NULL)
800			return ERR;
801		if (addr_cnt == 0 && !addr_last)
802			first_addr = second_addr = 0;
803		else if (check_addr_range(1, addr_last) < 0)
804			return ERR;
805		GET_COMMAND_SUFFIX();
806		if (*old_filename == '\0' && *fnp != '!')
807			strcpy(old_filename, fnp);
808#ifdef BACKWARDS
809		if (*fnp == '\0' && *old_filename == '\0') {
810			errmsg = "no current filename";
811			return ERR;
812		}
813#endif
814		if ((addr = write_file(*fnp ? fnp : old_filename,
815		    (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
816			return ERR;
817		else if (addr == addr_last)
818			modified = 0;
819		else if (modified && !scripted && n == 'q')
820			gflag = EMOD;
821		break;
822	case 'x':
823		if (addr_cnt > 0) {
824			errmsg = "unexpected address";
825			return ERR;
826		}
827		GET_COMMAND_SUFFIX();
828#ifdef DES
829		des = get_keyword();
830#else
831		errmsg = "crypt unavailable";
832		return ERR;
833#endif
834		break;
835	case 'z':
836#ifdef BACKWARDS
837		if (check_addr_range(first_addr = 1, current_addr + 1) < 0)
838#else
839		if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0)
840#endif
841			return ERR;
842		else if ('0' < *ibufp && *ibufp <= '9')
843			STRTOL(rows, ibufp);
844		GET_COMMAND_SUFFIX();
845		if (display_lines(second_addr, min(addr_last,
846		    second_addr + rows), gflag) < 0)
847			return ERR;
848		gflag = 0;
849		break;
850	case '=':
851		GET_COMMAND_SUFFIX();
852		printf("%ld\n", addr_cnt ? second_addr : addr_last);
853		break;
854	case '!':
855		if (addr_cnt > 0) {
856			errmsg = "unexpected address";
857			return ERR;
858		} else if ((sflags = get_shell_command()) < 0)
859			return ERR;
860		GET_COMMAND_SUFFIX();
861		if (sflags) printf("%s\n", shcmd + 1);
862		system(shcmd + 1);
863		if (!scripted) printf("!\n");
864		break;
865	case '\n':
866#ifdef BACKWARDS
867		if (check_addr_range(first_addr = 1, current_addr + 1) < 0
868#else
869		if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0
870#endif
871		 || display_lines(second_addr, second_addr, 0) < 0)
872			return ERR;
873		break;
874	default:
875		errmsg = "unknown command";
876		return ERR;
877	}
878	return gflag;
879}
880
881
882/* check_addr_range: return status of address range check */
883int
884check_addr_range(long n, long m)
885{
886	if (addr_cnt == 0) {
887		first_addr = n;
888		second_addr = m;
889	}
890	if (first_addr > second_addr || 1 > first_addr ||
891	    second_addr > addr_last) {
892		errmsg = "invalid address";
893		return ERR;
894	}
895	return 0;
896}
897
898
899/* get_matching_node_addr: return the address of the next line matching a
900   pattern in a given direction.  wrap around begin/end of editor buffer if
901   necessary */
902long
903get_matching_node_addr(pattern_t *pat, int dir)
904{
905	char *s;
906	long n = current_addr;
907	line_t *lp;
908
909	if (!pat) return ERR;
910	do {
911	       if ((n = dir ? INC_MOD(n, addr_last) : DEC_MOD(n, addr_last))) {
912			lp = get_addressed_line_node(n);
913			if ((s = get_sbuf_line(lp)) == NULL)
914				return ERR;
915			if (isbinary)
916				NUL_TO_NEWLINE(s, lp->len);
917			if (!regexec(pat, s, 0, NULL, 0))
918				return n;
919	       }
920	} while (n != current_addr);
921	errmsg = "no match";
922	return  ERR;
923}
924
925
926/* get_filename: return pointer to copy of filename in the command buffer */
927char *
928get_filename(void)
929{
930	static char *file = NULL;
931	static int filesz = 0;
932
933	int n;
934
935	if (*ibufp != '\n') {
936		SKIP_BLANKS();
937		if (*ibufp == '\n') {
938			errmsg = "invalid filename";
939			return NULL;
940		} else if ((ibufp = get_extended_line(&n, 1)) == NULL)
941			return NULL;
942		else if (*ibufp == '!') {
943			ibufp++;
944			if ((n = get_shell_command()) < 0)
945				return NULL;
946			if (n)
947				printf("%s\n", shcmd + 1);
948			return shcmd;
949		} else if (n > PATH_MAX - 1) {
950			errmsg = "filename too long";
951			return  NULL;
952		}
953	}
954#ifndef BACKWARDS
955	else if (*old_filename == '\0') {
956		errmsg = "no current filename";
957		return  NULL;
958	}
959#endif
960	REALLOC(file, filesz, PATH_MAX, NULL);
961	for (n = 0; *ibufp != '\n';)
962		file[n++] = *ibufp++;
963	file[n] = '\0';
964	return is_legal_filename(file) ? file : NULL;
965}
966
967
968/* get_shell_command: read a shell command from stdin; return substitution
969   status */
970int
971get_shell_command(void)
972{
973	static char *buf = NULL;
974	static int n = 0;
975
976	char *s;			/* substitution char pointer */
977	int i = 0;
978	int j = 0;
979
980	if (red) {
981		errmsg = "shell access restricted";
982		return ERR;
983	} else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
984		return ERR;
985	REALLOC(buf, n, j + 1, ERR);
986	buf[i++] = '!';			/* prefix command w/ bang */
987	while (*ibufp != '\n')
988		switch (*ibufp) {
989		default:
990			REALLOC(buf, n, i + 2, ERR);
991			buf[i++] = *ibufp;
992			if (*ibufp++ == '\\')
993				buf[i++] = *ibufp++;
994			break;
995		case '!':
996			if (s != ibufp) {
997				REALLOC(buf, n, i + 1, ERR);
998				buf[i++] = *ibufp++;
999			}
1000#ifdef BACKWARDS
1001			else if (shcmd == NULL || *(shcmd + 1) == '\0')
1002#else
1003			else if (shcmd == NULL)
1004#endif
1005			{
1006				errmsg = "no previous command";
1007				return ERR;
1008			} else {
1009				REALLOC(buf, n, i + shcmdi, ERR);
1010				for (s = shcmd + 1; s < shcmd + shcmdi;)
1011					buf[i++] = *s++;
1012				s = ibufp++;
1013			}
1014			break;
1015		case '%':
1016			if (*old_filename  == '\0') {
1017				errmsg = "no current filename";
1018				return ERR;
1019			}
1020			j = strlen(s = strip_escapes(old_filename));
1021			REALLOC(buf, n, i + j, ERR);
1022			while (j--)
1023				buf[i++] = *s++;
1024			s = ibufp++;
1025			break;
1026		}
1027	REALLOC(shcmd, shcmdsz, i + 1, ERR);
1028	memcpy(shcmd, buf, i);
1029	shcmd[shcmdi = i] = '\0';
1030	return *s == '!' || *s == '%';
1031}
1032
1033
1034/* append_lines: insert text from stdin to after line n; stop when either a
1035   single period is read or EOF; return status */
1036int
1037append_lines(long n)
1038{
1039	int l;
1040	const char *lp = ibuf;
1041	const char *eot;
1042	undo_t *up = NULL;
1043
1044	for (current_addr = n;;) {
1045		if (!isglobal) {
1046			if ((l = get_tty_line()) < 0)
1047				return ERR;
1048			else if (l == 0 || ibuf[l - 1] != '\n') {
1049				clearerr(stdin);
1050				return  l ? EOF : 0;
1051			}
1052			lp = ibuf;
1053		} else if (*(lp = ibufp) == '\0')
1054			return 0;
1055		else {
1056			while (*ibufp++ != '\n')
1057				;
1058			l = ibufp - lp;
1059		}
1060		if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1061			return 0;
1062		}
1063		eot = lp + l;
1064		SPL1();
1065		do {
1066			if ((lp = put_sbuf_line(lp)) == NULL) {
1067				SPL0();
1068				return ERR;
1069			} else if (up)
1070				up->t = get_addressed_line_node(current_addr);
1071			else if ((up = push_undo_stack(UADD, current_addr,
1072			    current_addr)) == NULL) {
1073				SPL0();
1074				return ERR;
1075			}
1076		} while (lp != eot);
1077		modified = 1;
1078		SPL0();
1079	}
1080	/* NOTREACHED */
1081}
1082
1083
1084/* join_lines: replace a range of lines with the joined text of those lines */
1085int
1086join_lines(long from, long to)
1087{
1088	static char *buf = NULL;
1089	static int n;
1090
1091	char *s;
1092	int size = 0;
1093	line_t *bp, *ep;
1094
1095	ep = get_addressed_line_node(INC_MOD(to, addr_last));
1096	bp = get_addressed_line_node(from);
1097	for (; bp != ep; bp = bp->q_forw) {
1098		if ((s = get_sbuf_line(bp)) == NULL)
1099			return ERR;
1100		REALLOC(buf, n, size + bp->len, ERR);
1101		memcpy(buf + size, s, bp->len);
1102		size += bp->len;
1103	}
1104	REALLOC(buf, n, size + 2, ERR);
1105	memcpy(buf + size, "\n", 2);
1106	if (delete_lines(from, to) < 0)
1107		return ERR;
1108	current_addr = from - 1;
1109	SPL1();
1110	if (put_sbuf_line(buf) == NULL ||
1111	    push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1112		SPL0();
1113		return ERR;
1114	}
1115	modified = 1;
1116	SPL0();
1117	return 0;
1118}
1119
1120
1121/* move_lines: move a range of lines */
1122int
1123move_lines(long addr)
1124{
1125	line_t *b1, *a1, *b2, *a2;
1126	long n = INC_MOD(second_addr, addr_last);
1127	long p = first_addr - 1;
1128	int done = (addr == first_addr - 1 || addr == second_addr);
1129
1130	SPL1();
1131	if (done) {
1132		a2 = get_addressed_line_node(n);
1133		b2 = get_addressed_line_node(p);
1134		current_addr = second_addr;
1135	} else if (push_undo_stack(UMOV, p, n) == NULL ||
1136	    push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1137		SPL0();
1138		return ERR;
1139	} else {
1140		a1 = get_addressed_line_node(n);
1141		if (addr < first_addr) {
1142			b1 = get_addressed_line_node(p);
1143			b2 = get_addressed_line_node(addr);
1144					/* this get_addressed_line_node last! */
1145		} else {
1146			b2 = get_addressed_line_node(addr);
1147			b1 = get_addressed_line_node(p);
1148					/* this get_addressed_line_node last! */
1149		}
1150		a2 = b2->q_forw;
1151		REQUE(b2, b1->q_forw);
1152		REQUE(a1->q_back, a2);
1153		REQUE(b1, a1);
1154		current_addr = addr + ((addr < first_addr) ?
1155		    second_addr - first_addr + 1 : 0);
1156	}
1157	if (isglobal)
1158		unset_active_nodes(b2->q_forw, a2);
1159	modified = 1;
1160	SPL0();
1161	return 0;
1162}
1163
1164
1165/* copy_lines: copy a range of lines; return status */
1166int
1167copy_lines(long addr)
1168{
1169	line_t *lp, *np = get_addressed_line_node(first_addr);
1170	undo_t *up = NULL;
1171	long n = second_addr - first_addr + 1;
1172	long m = 0;
1173
1174	current_addr = addr;
1175	if (first_addr <= addr && addr < second_addr) {
1176		n =  addr - first_addr + 1;
1177		m = second_addr - addr;
1178	}
1179	for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1180		for (; n-- > 0; np = np->q_forw) {
1181			SPL1();
1182			if ((lp = dup_line_node(np)) == NULL) {
1183				SPL0();
1184				return ERR;
1185			}
1186			add_line_node(lp);
1187			if (up)
1188				up->t = lp;
1189			else if ((up = push_undo_stack(UADD, current_addr,
1190			    current_addr)) == NULL) {
1191				SPL0();
1192				return ERR;
1193			}
1194			modified = 1;
1195			SPL0();
1196		}
1197	return 0;
1198}
1199
1200
1201/* delete_lines: delete a range of lines */
1202int
1203delete_lines(long from, long to)
1204{
1205	line_t *n, *p;
1206
1207	SPL1();
1208	if (push_undo_stack(UDEL, from, to) == NULL) {
1209		SPL0();
1210		return ERR;
1211	}
1212	n = get_addressed_line_node(INC_MOD(to, addr_last));
1213	p = get_addressed_line_node(from - 1);
1214					/* this get_addressed_line_node last! */
1215	if (isglobal)
1216		unset_active_nodes(p->q_forw, n);
1217	REQUE(p, n);
1218	addr_last -= to - from + 1;
1219	current_addr = from - 1;
1220	modified = 1;
1221	SPL0();
1222	return 0;
1223}
1224
1225
1226/* display_lines: print a range of lines to stdout */
1227int
1228display_lines(long from, long to, int gflag)
1229{
1230	line_t *bp;
1231	line_t *ep;
1232	char *s;
1233
1234	if (!from) {
1235		errmsg = "invalid address";
1236		return ERR;
1237	}
1238	ep = get_addressed_line_node(INC_MOD(to, addr_last));
1239	bp = get_addressed_line_node(from);
1240	for (; bp != ep; bp = bp->q_forw) {
1241		if ((s = get_sbuf_line(bp)) == NULL)
1242			return ERR;
1243		if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1244			return ERR;
1245	}
1246	return 0;
1247}
1248
1249
1250#define MAXMARK 26			/* max number of marks */
1251
1252line_t	*mark[MAXMARK];			/* line markers */
1253int markno;				/* line marker count */
1254
1255/* mark_line_node: set a line node mark */
1256int
1257mark_line_node(line_t *lp, int n)
1258{
1259	if (!islower((unsigned char)n)) {
1260		errmsg = "invalid mark character";
1261		return ERR;
1262	} else if (mark[n - 'a'] == NULL)
1263		markno++;
1264	mark[n - 'a'] = lp;
1265	return 0;
1266}
1267
1268
1269/* get_marked_node_addr: return address of a marked line */
1270long
1271get_marked_node_addr(int n)
1272{
1273	if (!islower((unsigned char)n)) {
1274		errmsg = "invalid mark character";
1275		return ERR;
1276	}
1277	return get_line_node_addr(mark[n - 'a']);
1278}
1279
1280
1281/* unmark_line_node: clear line node mark */
1282void
1283unmark_line_node(line_t *lp)
1284{
1285	int i;
1286
1287	for (i = 0; markno && i < MAXMARK; i++)
1288		if (mark[i] == lp) {
1289			mark[i] = NULL;
1290			markno--;
1291		}
1292}
1293
1294
1295/* dup_line_node: return a pointer to a copy of a line node */
1296line_t *
1297dup_line_node(line_t *lp)
1298{
1299	line_t *np;
1300
1301	if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1302		fprintf(stderr, "%s\n", strerror(errno));
1303		errmsg = "out of memory";
1304		return NULL;
1305	}
1306	np->seek = lp->seek;
1307	np->len = lp->len;
1308	return np;
1309}
1310
1311
1312/* has_trailing_escape:  return the parity of escapes preceding a character
1313   in a string */
1314int
1315has_trailing_escape(char *s, char *t)
1316{
1317    return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1318}
1319
1320
1321/* strip_escapes: return copy of escaped string of at most length PATH_MAX */
1322char *
1323strip_escapes(char *s)
1324{
1325	static char *file = NULL;
1326	static int filesz = 0;
1327
1328	int i = 0;
1329
1330	REALLOC(file, filesz, PATH_MAX, NULL);
1331	while (i < filesz - 1	/* Worry about a possible trailing escape */
1332	       && (file[i++] = (*s == '\\') ? *++s : *s))
1333		s++;
1334	return file;
1335}
1336
1337
1338void
1339signal_hup(int signo)
1340{
1341	if (mutex)
1342		sigflags |= (1 << (signo - 1));
1343	else
1344		handle_hup(signo);
1345}
1346
1347
1348void
1349signal_int(int signo)
1350{
1351	if (mutex)
1352		sigflags |= (1 << (signo - 1));
1353	else
1354		handle_int(signo);
1355}
1356
1357
1358void
1359handle_hup(int signo)
1360{
1361	char *hup = NULL;		/* hup filename */
1362	char *s;
1363	char ed_hup[] = "ed.hup";
1364	int n;
1365
1366	if (!sigactive)
1367		quit(1);
1368	sigflags &= ~(1 << (signo - 1));
1369	if (addr_last && write_file(ed_hup, "w", 1, addr_last) < 0 &&
1370	    (s = getenv("HOME")) != NULL &&
1371	    (n = strlen(s)) + 8 <= PATH_MAX &&	/* "ed.hup" + '/' */
1372	    (hup = (char *) malloc(n + 10)) != NULL) {
1373		strcpy(hup, s);
1374		if (hup[n - 1] != '/')
1375			hup[n] = '/', hup[n+1] = '\0';
1376		strcat(hup, "ed.hup");
1377		write_file(hup, "w", 1, addr_last);
1378	}
1379	quit(2);
1380}
1381
1382
1383void
1384handle_int(int signo)
1385{
1386	if (!sigactive)
1387		quit(1);
1388	sigflags &= ~(1 << (signo - 1));
1389#ifdef _POSIX_SOURCE
1390	siglongjmp(env, -1);
1391#else
1392	longjmp(env, -1);
1393#endif
1394}
1395
1396
1397int cols = 72;				/* wrap column */
1398
1399void
1400handle_winch(int signo)
1401{
1402	int save_errno = errno;
1403
1404	struct winsize ws;		/* window size structure */
1405
1406	sigflags &= ~(1 << (signo - 1));
1407	if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1408		if (ws.ws_row > 2) rows = ws.ws_row - 2;
1409		if (ws.ws_col > 8) cols = ws.ws_col - 8;
1410	}
1411	errno = save_errno;
1412}
1413
1414
1415/* is_legal_filename: return a legal filename */
1416int
1417is_legal_filename(char *s)
1418{
1419	if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1420		errmsg = "shell access restricted";
1421		return 0;
1422	}
1423	return 1;
1424}
1425