main.c revision 20420
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 *	$Id: main.c,v 1.6 1996/08/11 16:48:11 ache Exp $
29 */
30
31#ifndef lint
32static char * const copyright =
33"@(#) Copyright (c) 1993 Andrew Moore, Talke Studio. \n\
34 All rights reserved.\n";
35#endif /* not lint */
36
37#ifndef lint
38static char * const rcsid = "@(#)main.c,v 1.1 1994/02/01 00:34:42 alm Exp";
39#endif /* not lint */
40
41/*
42 * CREDITS
43 *
44 *	This program is based on the editor algorithm described in
45 *	Brian W. Kernighan and P. J. Plauger's book "Software Tools
46 *	in Pascal," Addison-Wesley, 1981.
47 *
48 *	The buffering algorithm is attributed to Rodney Ruddock of
49 *	the University of Guelph, Guelph, Ontario.
50 *
51 *	The cbc.c encryption code is adapted from
52 *	the bdes program by Matt Bishop of Dartmouth College,
53 *	Hanover, NH.
54 *
55 */
56
57#include <sys/ioctl.h>
58#include <sys/wait.h>
59#include <ctype.h>
60#include <setjmp.h>
61#include <pwd.h>
62#include <locale.h>
63
64#include "ed.h"
65
66
67#ifdef _POSIX_SOURCE
68sigjmp_buf env;
69#else
70jmp_buf env;
71#endif
72
73/* static buffers */
74char stdinbuf[1];		/* stdin buffer */
75char *shcmd;			/* shell command buffer */
76int shcmdsz;			/* shell command buffer size */
77int shcmdi;			/* shell command buffer index */
78char *ibuf;			/* ed command-line buffer */
79int ibufsz;			/* ed command-line buffer size */
80char *ibufp;			/* pointer to ed command-line buffer */
81
82/* global flags */
83int des = 0;			/* if set, use crypt(3) for i/o */
84int garrulous = 0;		/* if set, print all error messages */
85int isbinary;			/* if set, buffer contains ASCII NULs */
86int isglobal;			/* if set, doing a global command */
87int modified;			/* if set, buffer modified since last write */
88int mutex = 0;			/* if set, signals set "sigflags" */
89int red = 0;			/* if set, restrict shell/directory access */
90int scripted = 0;		/* if set, suppress diagnostics */
91int sigflags = 0;		/* if set, signals received while mutex set */
92int sigactive = 0;		/* if set, signal handlers are enabled */
93
94char old_filename[MAXPATHLEN + 1] = "";	/* default filename */
95long current_addr;		/* current address in editor buffer */
96long addr_last;			/* last address in editor buffer */
97int lineno;			/* script line number */
98char *prompt;			/* command-line prompt */
99char *dps = "*";		/* default command-line prompt */
100
101char *usage = "usage: %s [-] [-sx] [-p string] [name]\n";
102
103extern char errmsg[];
104extern int optind;
105extern char *optarg;
106
107/* ed: line editor */
108int
109main(argc, argv)
110	int argc;
111	char **argv;
112{
113	int c, n;
114	long status = 0;
115#if __GNUC__
116	/* Avoid longjmp clobbering */
117	(void) &argc;
118	(void) &argv;
119#endif
120
121	(void)setlocale(LC_ALL, "");
122
123	red = (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
124top:
125	while ((c = getopt(argc, argv, "p:sx")) != EOF)
126		switch(c) {
127		case 'p':				/* set prompt */
128			prompt = optarg;
129			break;
130		case 's':				/* run script */
131			scripted = 1;
132			break;
133		case 'x':				/* use crypt */
134#ifdef DES
135			des = get_keyword();
136#else
137			fprintf(stderr, "crypt unavailable\n?\n");
138#endif
139			break;
140
141		default:
142			fprintf(stderr, usage, argv[0]);
143			exit(1);
144		}
145	argv += optind;
146	argc -= optind;
147	if (argc && **argv == '-') {
148		scripted = 1;
149		if (argc > 1) {
150			optind = 1;
151			goto top;
152		}
153		argv++;
154		argc--;
155	}
156	/* assert: reliable signals! */
157#ifdef SIGWINCH
158	handle_winch(SIGWINCH);
159	if (isatty(0)) signal(SIGWINCH, handle_winch);
160#endif
161	signal(SIGHUP, signal_hup);
162	signal(SIGQUIT, SIG_IGN);
163	signal(SIGINT, signal_int);
164#ifdef _POSIX_SOURCE
165	if ((status = sigsetjmp(env, 1)))
166#else
167	if ((status = setjmp(env)))
168#endif
169	{
170		fputs("\n?\n", stderr);
171		sprintf(errmsg, "interrupt");
172	} else {
173		init_buffers();
174		sigactive = 1;			/* enable signal handlers */
175		if (argc && **argv && is_legal_filename(*argv)) {
176			if (read_file(*argv, 0) < 0 && !isatty(0))
177				quit(2);
178			else if (**argv != '!')
179				strcpy(old_filename, *argv);
180		} else if (argc) {
181			fputs("?\n", stderr);
182			if (**argv == '\0')
183				sprintf(errmsg, "invalid filename");
184			if (!isatty(0))
185				quit(2);
186		}
187	}
188	for (;;) {
189		if (status < 0 && garrulous)
190			fprintf(stderr, "%s\n", errmsg);
191		if (prompt) {
192			printf("%s", prompt);
193			fflush(stdout);
194		}
195		if ((n = get_tty_line()) < 0) {
196			status = ERR;
197			continue;
198		} else if (n == 0) {
199			if (modified && !scripted) {
200				fputs("?\n", stderr);
201				sprintf(errmsg, "warning: file modified");
202				if (!isatty(0)) {
203					fprintf(stderr, garrulous ?
204					    "script, line %d: %s\n" :
205					    "", lineno, errmsg);
206					quit(2);
207				}
208				clearerr(stdin);
209				modified = 0;
210				status = EMOD;
211				continue;
212			} else
213				quit(0);
214		} else if (ibuf[n - 1] != '\n') {
215			/* discard line */
216			sprintf(errmsg, "unexpected end-of-file");
217			clearerr(stdin);
218			status = ERR;
219			continue;
220		}
221		isglobal = 0;
222		if ((status = extract_addr_range()) >= 0 &&
223		    (status = exec_command()) >= 0)
224			if (!status ||
225			    (status = display_lines(current_addr, current_addr,
226			        status)) >= 0)
227				continue;
228		switch (status) {
229		case EOF:
230			quit(0);
231		case EMOD:
232			modified = 0;
233			fputs("?\n", stderr);		/* give warning */
234			sprintf(errmsg, "warning: file modified");
235			if (!isatty(0)) {
236				fprintf(stderr, garrulous ?
237				    "script, line %d: %s\n" :
238				    "", lineno, errmsg);
239				quit(2);
240			}
241			break;
242		case FATAL:
243			if (!isatty(0))
244				fprintf(stderr, garrulous ?
245				    "script, line %d: %s\n" : "",
246				    lineno, errmsg);
247			else
248				fprintf(stderr, garrulous ? "%s\n" : "",
249				    errmsg);
250			quit(3);
251		default:
252			fputs("?\n", stderr);
253			if (!isatty(0)) {
254				fprintf(stderr, garrulous ?
255				    "script, line %d: %s\n" : "",
256				    lineno, errmsg);
257				quit(2);
258			}
259			break;
260		}
261	}
262	/*NOTREACHED*/
263}
264
265long first_addr, second_addr, addr_cnt;
266
267/* extract_addr_range: get line addresses from the command buffer until an
268   illegal address is seen; return status */
269int
270extract_addr_range()
271{
272	long addr;
273
274	addr_cnt = 0;
275	first_addr = second_addr = current_addr;
276	while ((addr = next_addr()) >= 0) {
277		addr_cnt++;
278		first_addr = second_addr;
279		second_addr = addr;
280		if (*ibufp != ',' && *ibufp != ';')
281			break;
282		else if (*ibufp++ == ';')
283			current_addr = addr;
284	}
285	if ((addr_cnt = min(addr_cnt, 2)) == 1 || second_addr != addr)
286		first_addr = second_addr;
287	return (addr == ERR) ? ERR : 0;
288}
289
290
291#define SKIP_BLANKS() while (isspace((unsigned char)*ibufp) && *ibufp != '\n') ibufp++
292
293#define MUST_BE_FIRST() \
294	if (!first) { sprintf(errmsg, "invalid address"); return ERR; }
295
296/*  next_addr: return the next line address in the command buffer */
297long
298next_addr()
299{
300	char *hd;
301	long addr = current_addr;
302	long n;
303	int first = 1;
304	int c;
305
306	SKIP_BLANKS();
307	for (hd = ibufp;; first = 0)
308		switch (c = *ibufp) {
309		case '+':
310		case '\t':
311		case ' ':
312		case '-':
313		case '^':
314			ibufp++;
315			SKIP_BLANKS();
316			if (isdigit((unsigned char)*ibufp)) {
317				STRTOL(n, ibufp);
318				addr += (c == '-' || c == '^') ? -n : n;
319			} else if (!isspace((unsigned char)c))
320				addr += (c == '-' || c == '^') ? -1 : 1;
321			break;
322		case '0': case '1': case '2':
323		case '3': case '4': case '5':
324		case '6': case '7': case '8': case '9':
325			MUST_BE_FIRST();
326			STRTOL(addr, ibufp);
327			break;
328		case '.':
329		case '$':
330			MUST_BE_FIRST();
331			ibufp++;
332			addr = (c == '.') ? current_addr : addr_last;
333			break;
334		case '/':
335		case '?':
336			MUST_BE_FIRST();
337			if ((addr = get_matching_node_addr(
338			    get_compiled_pattern(), c == '/')) < 0)
339				return ERR;
340			else if (c == *ibufp)
341				ibufp++;
342			break;
343		case '\'':
344			MUST_BE_FIRST();
345			ibufp++;
346			if ((addr = get_marked_node_addr(*ibufp++)) < 0)
347				return ERR;
348			break;
349		case '%':
350		case ',':
351		case ';':
352			if (first) {
353				ibufp++;
354				addr_cnt++;
355				second_addr = (c == ';') ? current_addr : 1;
356				addr = addr_last;
357				break;
358			}
359			/* FALL THROUGH */
360		default:
361			if (ibufp == hd)
362				return EOF;
363			else if (addr < 0 || addr_last < addr) {
364				sprintf(errmsg, "invalid address");
365				return ERR;
366			} else
367				return addr;
368		}
369	/* NOTREACHED */
370}
371
372
373#ifdef BACKWARDS
374/* GET_THIRD_ADDR: get a legal address from the command buffer */
375#define GET_THIRD_ADDR(addr) \
376{ \
377	long ol1, ol2; \
378\
379	ol1 = first_addr, ol2 = second_addr; \
380	if (extract_addr_range() < 0) \
381		return ERR; \
382	else if (addr_cnt == 0) { \
383		sprintf(errmsg, "destination expected"); \
384		return ERR; \
385	} else if (second_addr < 0 || addr_last < second_addr) { \
386		sprintf(errmsg, "invalid address"); \
387		return ERR; \
388	} \
389	addr = second_addr; \
390	first_addr = ol1, second_addr = ol2; \
391}
392#else	/* BACKWARDS */
393/* GET_THIRD_ADDR: get a legal address from the command buffer */
394#define GET_THIRD_ADDR(addr) \
395{ \
396	long ol1, ol2; \
397\
398	ol1 = first_addr, ol2 = second_addr; \
399	if (extract_addr_range() < 0) \
400		return ERR; \
401	if (second_addr < 0 || addr_last < second_addr) { \
402		sprintf(errmsg, "invalid address"); \
403		return ERR; \
404	} \
405	addr = second_addr; \
406	first_addr = ol1, second_addr = ol2; \
407}
408#endif
409
410
411/* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
412#define GET_COMMAND_SUFFIX() { \
413	int done = 0; \
414	do { \
415		switch(*ibufp) { \
416		case 'p': \
417			gflag |= GPR, ibufp++; \
418			break; \
419		case 'l': \
420			gflag |= GLS, ibufp++; \
421			break; \
422		case 'n': \
423			gflag |= GNP, ibufp++; \
424			break; \
425		default: \
426			done++; \
427		} \
428	} while (!done); \
429	if (*ibufp++ != '\n') { \
430		sprintf(errmsg, "invalid command suffix"); \
431		return ERR; \
432	} \
433}
434
435
436/* sflags */
437#define SGG 001		/* complement previous global substitute suffix */
438#define SGP 002		/* complement previous print suffix */
439#define SGR 004		/* use last regex instead of last pat */
440#define SGF 010		/* repeat last substitution */
441
442int patlock = 0;	/* if set, pattern not freed by get_compiled_pattern() */
443
444long rows = 22;		/* scroll length: ws_row - 2 */
445
446/* exec_command: execute the next command in command buffer; return print
447   request, if any */
448int
449exec_command()
450{
451	extern long u_current_addr;
452	extern long u_addr_last;
453
454	static pattern_t *pat = NULL;
455	static int sgflag = 0;
456	static int sgnum = 0;
457
458	pattern_t *tpat;
459	char *fnp;
460	int gflag = 0;
461	int sflags = 0;
462	long addr = 0;
463	int n = 0;
464	int c;
465
466	SKIP_BLANKS();
467	switch(c = *ibufp++) {
468	case 'a':
469		GET_COMMAND_SUFFIX();
470		if (!isglobal) clear_undo_stack();
471		if (append_lines(second_addr) < 0)
472			return ERR;
473		break;
474	case 'c':
475		if (check_addr_range(current_addr, current_addr) < 0)
476			return ERR;
477		GET_COMMAND_SUFFIX();
478		if (!isglobal) clear_undo_stack();
479		if (delete_lines(first_addr, second_addr) < 0 ||
480		    append_lines(current_addr) < 0)
481			return ERR;
482		break;
483	case 'd':
484		if (check_addr_range(current_addr, current_addr) < 0)
485			return ERR;
486		GET_COMMAND_SUFFIX();
487		if (!isglobal) clear_undo_stack();
488		if (delete_lines(first_addr, second_addr) < 0)
489			return ERR;
490		else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
491			current_addr = addr;
492		break;
493	case 'e':
494		if (modified && !scripted)
495			return EMOD;
496		/* fall through */
497	case 'E':
498		if (addr_cnt > 0) {
499			sprintf(errmsg, "unexpected address");
500			return ERR;
501		} else if (!isspace((unsigned char)*ibufp)) {
502			sprintf(errmsg, "unexpected command suffix");
503			return ERR;
504		} else if ((fnp = get_filename()) == NULL)
505			return ERR;
506		GET_COMMAND_SUFFIX();
507		if (delete_lines(1, addr_last) < 0)
508			return ERR;
509		clear_undo_stack();
510		if (close_sbuf() < 0)
511			return ERR;
512		else if (open_sbuf() < 0)
513			return FATAL;
514		if (*fnp && *fnp != '!') strcpy(old_filename, fnp);
515#ifdef BACKWARDS
516		if (*fnp == '\0' && *old_filename == '\0') {
517			sprintf(errmsg, "no current filename");
518			return ERR;
519		}
520#endif
521		if (read_file(*fnp ? fnp : old_filename, 0) < 0)
522			return ERR;
523		clear_undo_stack();
524		modified = 0;
525		u_current_addr = u_addr_last = -1;
526		break;
527	case 'f':
528		if (addr_cnt > 0) {
529			sprintf(errmsg, "unexpected address");
530			return ERR;
531		} else if (!isspace((unsigned char)*ibufp)) {
532			sprintf(errmsg, "unexpected command suffix");
533			return ERR;
534		} else if ((fnp = get_filename()) == NULL)
535			return ERR;
536		else if (*fnp == '!') {
537			sprintf(errmsg, "invalid redirection");
538			return ERR;
539		}
540		GET_COMMAND_SUFFIX();
541		if (*fnp) strcpy(old_filename, fnp);
542		printf("%s\n", strip_escapes(old_filename));
543		break;
544	case 'g':
545	case 'v':
546	case 'G':
547	case 'V':
548		if (isglobal) {
549			sprintf(errmsg, "cannot nest global commands");
550			return ERR;
551		} else if (check_addr_range(1, addr_last) < 0)
552			return ERR;
553		else if (build_active_list(c == 'g' || c == 'G') < 0)
554			return ERR;
555		else if ((n = (c == 'G' || c == 'V')))
556			GET_COMMAND_SUFFIX();
557		isglobal++;
558		if (exec_global(n, gflag) < 0)
559			return ERR;
560		break;
561	case 'h':
562		if (addr_cnt > 0) {
563			sprintf(errmsg, "unexpected address");
564			return ERR;
565		}
566		GET_COMMAND_SUFFIX();
567		if (*errmsg) fprintf(stderr, "%s\n", errmsg);
568		break;
569	case 'H':
570		if (addr_cnt > 0) {
571			sprintf(errmsg, "unexpected address");
572			return ERR;
573		}
574		GET_COMMAND_SUFFIX();
575		if ((garrulous = 1 - garrulous) && *errmsg)
576			fprintf(stderr, "%s\n", errmsg);
577		break;
578	case 'i':
579		if (second_addr == 0) {
580			sprintf(errmsg, "invalid address");
581			return ERR;
582		}
583		GET_COMMAND_SUFFIX();
584		if (!isglobal) clear_undo_stack();
585		if (append_lines(second_addr - 1) < 0)
586			return ERR;
587		break;
588	case 'j':
589		if (check_addr_range(current_addr, current_addr + 1) < 0)
590			return ERR;
591		GET_COMMAND_SUFFIX();
592		if (!isglobal) clear_undo_stack();
593		if (first_addr != second_addr &&
594		    join_lines(first_addr, second_addr) < 0)
595			return ERR;
596		break;
597	case 'k':
598		c = *ibufp++;
599		if (second_addr == 0) {
600			sprintf(errmsg, "invalid address");
601			return ERR;
602		}
603		GET_COMMAND_SUFFIX();
604		if (mark_line_node(get_addressed_line_node(second_addr), c) < 0)
605			return ERR;
606		break;
607	case 'l':
608		if (check_addr_range(current_addr, current_addr) < 0)
609			return ERR;
610		GET_COMMAND_SUFFIX();
611		if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
612			return ERR;
613		gflag = 0;
614		break;
615	case 'm':
616		if (check_addr_range(current_addr, current_addr) < 0)
617			return ERR;
618		GET_THIRD_ADDR(addr);
619		if (first_addr <= addr && addr < second_addr) {
620			sprintf(errmsg, "invalid destination");
621			return ERR;
622		}
623		GET_COMMAND_SUFFIX();
624		if (!isglobal) clear_undo_stack();
625		if (move_lines(addr) < 0)
626			return ERR;
627		break;
628	case 'n':
629		if (check_addr_range(current_addr, current_addr) < 0)
630			return ERR;
631		GET_COMMAND_SUFFIX();
632		if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
633			return ERR;
634		gflag = 0;
635		break;
636	case 'p':
637		if (check_addr_range(current_addr, current_addr) < 0)
638			return ERR;
639		GET_COMMAND_SUFFIX();
640		if (display_lines(first_addr, second_addr, gflag | GPR) < 0)
641			return ERR;
642		gflag = 0;
643		break;
644	case 'P':
645		if (addr_cnt > 0) {
646			sprintf(errmsg, "unexpected address");
647			return ERR;
648		}
649		GET_COMMAND_SUFFIX();
650		prompt = prompt ? NULL : optarg ? optarg : dps;
651		break;
652	case 'q':
653	case 'Q':
654		if (addr_cnt > 0) {
655			sprintf(errmsg, "unexpected address");
656			return ERR;
657		}
658		GET_COMMAND_SUFFIX();
659		gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
660		break;
661	case 'r':
662		if (!isspace((unsigned char)*ibufp)) {
663			sprintf(errmsg, "unexpected command suffix");
664			return ERR;
665		} else if (addr_cnt == 0)
666			second_addr = addr_last;
667		if ((fnp = get_filename()) == NULL)
668			return ERR;
669		GET_COMMAND_SUFFIX();
670		if (!isglobal) clear_undo_stack();
671		if (*old_filename == '\0' && *fnp != '!')
672			strcpy(old_filename, fnp);
673#ifdef BACKWARDS
674		if (*fnp == '\0' && *old_filename == '\0') {
675			sprintf(errmsg, "no current filename");
676			return ERR;
677		}
678#endif
679		if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
680			return ERR;
681		else if (addr && addr != addr_last)
682			modified = 1;
683		break;
684	case 's':
685		do {
686			switch(*ibufp) {
687			case '\n':
688				sflags |=SGF;
689				break;
690			case 'g':
691				sflags |= SGG;
692				ibufp++;
693				break;
694			case 'p':
695				sflags |= SGP;
696				ibufp++;
697				break;
698			case 'r':
699				sflags |= SGR;
700				ibufp++;
701				break;
702			case '0': case '1': case '2': case '3': case '4':
703			case '5': case '6': case '7': case '8': case '9':
704				STRTOL(sgnum, ibufp);
705				sflags |= SGF;
706				sgflag &= ~GSG;		/* override GSG */
707				break;
708			default:
709				if (sflags) {
710					sprintf(errmsg, "invalid command suffix");
711					return ERR;
712				}
713			}
714		} while (sflags && *ibufp != '\n');
715		if (sflags && !pat) {
716			sprintf(errmsg, "no previous substitution");
717			return ERR;
718		} else if (sflags & SGG)
719			sgnum = 0;		/* override numeric arg */
720		if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
721			sprintf(errmsg, "invalid pattern delimiter");
722			return ERR;
723		}
724		tpat = pat;
725		SPL1();
726		if ((!sflags || (sflags & SGR)) &&
727		    (tpat = get_compiled_pattern()) == NULL) {
728		 	SPL0();
729			return ERR;
730		} else if (tpat != pat) {
731			if (pat) {
732				regfree(pat);
733				free(pat);
734			}
735			pat = tpat;
736			patlock = 1;		/* reserve pattern */
737		}
738		SPL0();
739		if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
740			return ERR;
741		else if (isglobal)
742			sgflag |= GLB;
743		else
744			sgflag &= ~GLB;
745		if (sflags & SGG)
746			sgflag ^= GSG;
747		if (sflags & SGP)
748			sgflag ^= GPR, sgflag &= ~(GLS | GNP);
749		do {
750			switch(*ibufp) {
751			case 'p':
752				sgflag |= GPR, ibufp++;
753				break;
754			case 'l':
755				sgflag |= GLS, ibufp++;
756				break;
757			case 'n':
758				sgflag |= GNP, ibufp++;
759				break;
760			default:
761				n++;
762			}
763		} while (!n);
764		if (check_addr_range(current_addr, current_addr) < 0)
765			return ERR;
766		GET_COMMAND_SUFFIX();
767		if (!isglobal) clear_undo_stack();
768		if (search_and_replace(pat, sgflag, sgnum) < 0)
769			return ERR;
770		break;
771	case 't':
772		if (check_addr_range(current_addr, current_addr) < 0)
773			return ERR;
774		GET_THIRD_ADDR(addr);
775		GET_COMMAND_SUFFIX();
776		if (!isglobal) clear_undo_stack();
777		if (copy_lines(addr) < 0)
778			return ERR;
779		break;
780	case 'u':
781		if (addr_cnt > 0) {
782			sprintf(errmsg, "unexpected address");
783			return ERR;
784		}
785		GET_COMMAND_SUFFIX();
786		if (pop_undo_stack() < 0)
787			return ERR;
788		break;
789	case 'w':
790	case 'W':
791		if ((n = *ibufp) == 'q' || n == 'Q') {
792			gflag = EOF;
793			ibufp++;
794		}
795		if (!isspace((unsigned char)*ibufp)) {
796			sprintf(errmsg, "unexpected command suffix");
797			return ERR;
798		} else if ((fnp = get_filename()) == NULL)
799			return ERR;
800		if (addr_cnt == 0 && !addr_last)
801			first_addr = second_addr = 0;
802		else if (check_addr_range(1, addr_last) < 0)
803			return ERR;
804		GET_COMMAND_SUFFIX();
805		if (*old_filename == '\0' && *fnp != '!')
806			strcpy(old_filename, fnp);
807#ifdef BACKWARDS
808		if (*fnp == '\0' && *old_filename == '\0') {
809			sprintf(errmsg, "no current filename");
810			return ERR;
811		}
812#endif
813		if ((addr = write_file(*fnp ? fnp : old_filename,
814		    (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
815			return ERR;
816		else if (addr == addr_last)
817			modified = 0;
818		else if (modified && !scripted && n == 'q')
819			gflag = EMOD;
820		break;
821	case 'x':
822		if (addr_cnt > 0) {
823			sprintf(errmsg, "unexpected address");
824			return ERR;
825		}
826		GET_COMMAND_SUFFIX();
827#ifdef DES
828		des = get_keyword();
829#else
830		sprintf(errmsg, "crypt unavailable");
831		return ERR;
832#endif
833		break;
834	case 'z':
835#ifdef BACKWARDS
836		if (check_addr_range(first_addr = 1, current_addr + 1) < 0)
837#else
838		if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0)
839#endif
840			return ERR;
841		else if ('0' < *ibufp && *ibufp <= '9')
842			STRTOL(rows, ibufp);
843		GET_COMMAND_SUFFIX();
844		if (display_lines(second_addr, min(addr_last,
845		    second_addr + rows), gflag) < 0)
846			return ERR;
847		gflag = 0;
848		break;
849	case '=':
850		GET_COMMAND_SUFFIX();
851		printf("%ld\n", addr_cnt ? second_addr : addr_last);
852		break;
853	case '!':
854		if (addr_cnt > 0) {
855			sprintf(errmsg, "unexpected address");
856			return ERR;
857		} else if ((sflags = get_shell_command()) < 0)
858			return ERR;
859		GET_COMMAND_SUFFIX();
860		if (sflags) printf("%s\n", shcmd + 1);
861		system(shcmd + 1);
862		if (!scripted) printf("!\n");
863		break;
864	case '\n':
865#ifdef BACKWARDS
866		if (check_addr_range(first_addr = 1, current_addr + 1) < 0
867#else
868		if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0
869#endif
870		 || display_lines(second_addr, second_addr, 0) < 0)
871			return ERR;
872		break;
873	default:
874		sprintf(errmsg, "unknown command");
875		return ERR;
876	}
877	return gflag;
878}
879
880
881/* check_addr_range: return status of address range check */
882int
883check_addr_range(n, m)
884	long n, 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		sprintf(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(pat, dir)
904	pattern_t *pat;
905	int dir;
906{
907	char *s;
908	long n = current_addr;
909	line_t *lp;
910
911	if (!pat) return ERR;
912	do {
913	       if ((n = dir ? INC_MOD(n, addr_last) : DEC_MOD(n, addr_last))) {
914			lp = get_addressed_line_node(n);
915			if ((s = get_sbuf_line(lp)) == NULL)
916				return ERR;
917			if (isbinary)
918				NUL_TO_NEWLINE(s, lp->len);
919			if (!regexec(pat, s, 0, NULL, 0))
920				return n;
921	       }
922	} while (n != current_addr);
923	sprintf(errmsg, "no match");
924	return  ERR;
925}
926
927
928/* get_filename: return pointer to copy of filename in the command buffer */
929char *
930get_filename()
931{
932	static char *file = NULL;
933	static int filesz = 0;
934
935	int n;
936
937	if (*ibufp != '\n') {
938		SKIP_BLANKS();
939		if (*ibufp == '\n') {
940			sprintf(errmsg, "invalid filename");
941			return NULL;
942		} else if ((ibufp = get_extended_line(&n, 1)) == NULL)
943			return NULL;
944		else if (*ibufp == '!') {
945			ibufp++;
946			if ((n = get_shell_command()) < 0)
947				return NULL;
948			if (n) printf("%s\n", shcmd + 1);
949			return shcmd;
950		} else if (n - 1 > MAXPATHLEN) {
951			sprintf(errmsg, "filename too long");
952			return  NULL;
953		}
954	}
955#ifndef BACKWARDS
956	else if (*old_filename == '\0') {
957		sprintf(errmsg, "no current filename");
958		return  NULL;
959	}
960#endif
961	REALLOC(file, filesz, MAXPATHLEN + 1, NULL);
962	for (n = 0; *ibufp != '\n';)
963		file[n++] = *ibufp++;
964	file[n] = '\0';
965	return is_legal_filename(file) ? file : NULL;
966}
967
968
969/* get_shell_command: read a shell command from stdin; return substitution
970   status */
971int
972get_shell_command()
973{
974	static char *buf = NULL;
975	static int n = 0;
976
977	char *s;			/* substitution char pointer */
978	int i = 0;
979	int j = 0;
980
981	if (red) {
982		sprintf(errmsg, "shell access restricted");
983		return ERR;
984	} else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
985		return ERR;
986	REALLOC(buf, n, j + 1, ERR);
987	buf[i++] = '!';			/* prefix command w/ bang */
988	while (*ibufp != '\n')
989		switch (*ibufp) {
990		default:
991			REALLOC(buf, n, i + 2, ERR);
992			buf[i++] = *ibufp;
993			if (*ibufp++ == '\\')
994				buf[i++] = *ibufp++;
995			break;
996		case '!':
997			if (s != ibufp) {
998				REALLOC(buf, n, i + 1, ERR);
999				buf[i++] = *ibufp++;
1000			}
1001#ifdef BACKWARDS
1002			else if (shcmd == NULL || *(shcmd + 1) == '\0')
1003#else
1004			else if (shcmd == NULL)
1005#endif
1006			{
1007				sprintf(errmsg, "no previous command");
1008				return ERR;
1009			} else {
1010				REALLOC(buf, n, i + shcmdi, ERR);
1011				for (s = shcmd + 1; s < shcmd + shcmdi;)
1012					buf[i++] = *s++;
1013				s = ibufp++;
1014			}
1015			break;
1016		case '%':
1017			if (*old_filename  == '\0') {
1018				sprintf(errmsg, "no current filename");
1019				return ERR;
1020			}
1021			j = strlen(s = strip_escapes(old_filename));
1022			REALLOC(buf, n, i + j, ERR);
1023			while (j--)
1024				buf[i++] = *s++;
1025			s = ibufp++;
1026			break;
1027		}
1028	REALLOC(shcmd, shcmdsz, i + 1, ERR);
1029	memcpy(shcmd, buf, i);
1030	shcmd[shcmdi = i] = '\0';
1031	return *s == '!' || *s == '%';
1032}
1033
1034
1035/* append_lines: insert text from stdin to after line n; stop when either a
1036   single period is read or EOF; return status */
1037int
1038append_lines(n)
1039	long n;
1040{
1041	int l;
1042	char *lp = ibuf;
1043	char *eot;
1044	undo_t *up = NULL;
1045
1046	for (current_addr = n;;) {
1047		if (!isglobal) {
1048			if ((l = get_tty_line()) < 0)
1049				return ERR;
1050			else if (l == 0 || ibuf[l - 1] != '\n') {
1051				clearerr(stdin);
1052				return  l ? EOF : 0;
1053			}
1054			lp = ibuf;
1055		} else if (*(lp = ibufp) == '\0')
1056			return 0;
1057		else {
1058			while (*ibufp++ != '\n')
1059				;
1060			l = ibufp - lp;
1061		}
1062		if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1063			return 0;
1064		}
1065		eot = lp + l;
1066		SPL1();
1067		do {
1068			if ((lp = put_sbuf_line(lp)) == NULL) {
1069				SPL0();
1070				return ERR;
1071			} else if (up)
1072				up->t = get_addressed_line_node(current_addr);
1073			else if ((up = push_undo_stack(UADD, current_addr,
1074			    current_addr)) == NULL) {
1075				SPL0();
1076				return ERR;
1077			}
1078		} while (lp != eot);
1079		modified = 1;
1080		SPL0();
1081	}
1082	/* NOTREACHED */
1083}
1084
1085
1086/* join_lines: replace a range of lines with the joined text of those lines */
1087int
1088join_lines(from, to)
1089	long from;
1090	long to;
1091{
1092	static char *buf = NULL;
1093	static int n;
1094
1095	char *s;
1096	int size = 0;
1097	line_t *bp, *ep;
1098
1099	ep = get_addressed_line_node(INC_MOD(to, addr_last));
1100	bp = get_addressed_line_node(from);
1101	for (; bp != ep; bp = bp->q_forw) {
1102		if ((s = get_sbuf_line(bp)) == NULL)
1103			return ERR;
1104		REALLOC(buf, n, size + bp->len, ERR);
1105		memcpy(buf + size, s, bp->len);
1106		size += bp->len;
1107	}
1108	REALLOC(buf, n, size + 2, ERR);
1109	memcpy(buf + size, "\n", 2);
1110	if (delete_lines(from, to) < 0)
1111		return ERR;
1112	current_addr = from - 1;
1113	SPL1();
1114	if (put_sbuf_line(buf) == NULL ||
1115	    push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1116		SPL0();
1117		return ERR;
1118	}
1119	modified = 1;
1120	SPL0();
1121	return 0;
1122}
1123
1124
1125/* move_lines: move a range of lines */
1126int
1127move_lines(addr)
1128	long addr;
1129{
1130	line_t *b1, *a1, *b2, *a2;
1131	long n = INC_MOD(second_addr, addr_last);
1132	long p = first_addr - 1;
1133	int done = (addr == first_addr - 1 || addr == second_addr);
1134
1135	SPL1();
1136	if (done) {
1137		a2 = get_addressed_line_node(n);
1138		b2 = get_addressed_line_node(p);
1139		current_addr = second_addr;
1140	} else if (push_undo_stack(UMOV, p, n) == NULL ||
1141	    push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1142		SPL0();
1143		return ERR;
1144	} else {
1145		a1 = get_addressed_line_node(n);
1146		if (addr < first_addr) {
1147			b1 = get_addressed_line_node(p);
1148			b2 = get_addressed_line_node(addr);
1149					/* this get_addressed_line_node last! */
1150		} else {
1151			b2 = get_addressed_line_node(addr);
1152			b1 = get_addressed_line_node(p);
1153					/* this get_addressed_line_node last! */
1154		}
1155		a2 = b2->q_forw;
1156		REQUE(b2, b1->q_forw);
1157		REQUE(a1->q_back, a2);
1158		REQUE(b1, a1);
1159		current_addr = addr + ((addr < first_addr) ?
1160		    second_addr - first_addr + 1 : 0);
1161	}
1162	if (isglobal)
1163		unset_active_nodes(b2->q_forw, a2);
1164	modified = 1;
1165	SPL0();
1166	return 0;
1167}
1168
1169
1170/* copy_lines: copy a range of lines; return status */
1171int
1172copy_lines(addr)
1173	long addr;
1174{
1175	line_t *lp, *np = get_addressed_line_node(first_addr);
1176	undo_t *up = NULL;
1177	long n = second_addr - first_addr + 1;
1178	long m = 0;
1179
1180	current_addr = addr;
1181	if (first_addr <= addr && addr < second_addr) {
1182		n =  addr - first_addr + 1;
1183		m = second_addr - addr;
1184	}
1185	for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1186		for (; n-- > 0; np = np->q_forw) {
1187			SPL1();
1188			if ((lp = dup_line_node(np)) == NULL) {
1189				SPL0();
1190				return ERR;
1191			}
1192			add_line_node(lp);
1193			if (up)
1194				up->t = lp;
1195			else if ((up = push_undo_stack(UADD, current_addr,
1196			    current_addr)) == NULL) {
1197				SPL0();
1198				return ERR;
1199			}
1200			modified = 1;
1201			SPL0();
1202		}
1203	return 0;
1204}
1205
1206
1207/* delete_lines: delete a range of lines */
1208int
1209delete_lines(from, to)
1210	long from, to;
1211{
1212	line_t *n, *p;
1213
1214	SPL1();
1215	if (push_undo_stack(UDEL, from, to) == NULL) {
1216		SPL0();
1217		return ERR;
1218	}
1219	n = get_addressed_line_node(INC_MOD(to, addr_last));
1220	p = get_addressed_line_node(from - 1);
1221					/* this get_addressed_line_node last! */
1222	if (isglobal)
1223		unset_active_nodes(p->q_forw, n);
1224	REQUE(p, n);
1225	addr_last -= to - from + 1;
1226	current_addr = from - 1;
1227	modified = 1;
1228	SPL0();
1229	return 0;
1230}
1231
1232
1233/* display_lines: print a range of lines to stdout */
1234int
1235display_lines(from, to, gflag)
1236	long from;
1237	long to;
1238	int gflag;
1239{
1240	line_t *bp;
1241	line_t *ep;
1242	char *s;
1243
1244	if (!from) {
1245		sprintf(errmsg, "invalid address");
1246		return ERR;
1247	}
1248	ep = get_addressed_line_node(INC_MOD(to, addr_last));
1249	bp = get_addressed_line_node(from);
1250	for (; bp != ep; bp = bp->q_forw) {
1251		if ((s = get_sbuf_line(bp)) == NULL)
1252			return ERR;
1253		if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1254			return ERR;
1255	}
1256	return 0;
1257}
1258
1259
1260#define MAXMARK 26			/* max number of marks */
1261
1262line_t	*mark[MAXMARK];			/* line markers */
1263int markno;				/* line marker count */
1264
1265/* mark_line_node: set a line node mark */
1266int
1267mark_line_node(lp, n)
1268	line_t *lp;
1269	int n;
1270{
1271	if (!islower((unsigned char)n)) {
1272		sprintf(errmsg, "invalid mark character");
1273		return ERR;
1274	} else if (mark[n - 'a'] == NULL)
1275		markno++;
1276	mark[n - 'a'] = lp;
1277	return 0;
1278}
1279
1280
1281/* get_marked_node_addr: return address of a marked line */
1282long
1283get_marked_node_addr(n)
1284	int n;
1285{
1286	if (!islower((unsigned char)n)) {
1287		sprintf(errmsg, "invalid mark character");
1288		return ERR;
1289	}
1290	return get_line_node_addr(mark[n - 'a']);
1291}
1292
1293
1294/* unmark_line_node: clear line node mark */
1295void
1296unmark_line_node(lp)
1297	line_t *lp;
1298{
1299	int i;
1300
1301	for (i = 0; markno && i < MAXMARK; i++)
1302		if (mark[i] == lp) {
1303			mark[i] = NULL;
1304			markno--;
1305		}
1306}
1307
1308
1309/* dup_line_node: return a pointer to a copy of a line node */
1310line_t *
1311dup_line_node(lp)
1312	line_t *lp;
1313{
1314	line_t *np;
1315
1316	if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1317		fprintf(stderr, "%s\n", strerror(errno));
1318		sprintf(errmsg, "out of memory");
1319		return NULL;
1320	}
1321	np->seek = lp->seek;
1322	np->len = lp->len;
1323	return np;
1324}
1325
1326
1327/* has_trailing_escape:  return the parity of escapes preceding a character
1328   in a string */
1329int
1330has_trailing_escape(s, t)
1331	char *s;
1332	char *t;
1333{
1334    return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1335}
1336
1337
1338/* strip_escapes: return copy of escaped string of at most length MAXPATHLEN */
1339char *
1340strip_escapes(s)
1341	char *s;
1342{
1343	static char *file = NULL;
1344	static int filesz = 0;
1345
1346	int i = 0;
1347
1348	REALLOC(file, filesz, MAXPATHLEN + 1, NULL);
1349	/* assert: no trailing escape */
1350	while ((file[i++] = (*s == '\\') ? *++s : *s))
1351		s++;
1352	return file;
1353}
1354
1355
1356void
1357signal_hup(signo)
1358	int signo;
1359{
1360	if (mutex)
1361		sigflags |= (1 << (signo - 1));
1362	else	handle_hup(signo);
1363}
1364
1365
1366void
1367signal_int(signo)
1368	int signo;
1369{
1370	if (mutex)
1371		sigflags |= (1 << (signo - 1));
1372	else	handle_int(signo);
1373}
1374
1375
1376void
1377handle_hup(signo)
1378	int signo;
1379{
1380	char *hup = NULL;		/* hup filename */
1381	char *s;
1382	int n;
1383
1384	if (!sigactive)
1385		quit(1);
1386	sigflags &= ~(1 << (signo - 1));
1387	if (addr_last && write_file("ed.hup", "w", 1, addr_last) < 0 &&
1388	    (s = getenv("HOME")) != NULL &&
1389	    (n = strlen(s)) + 8 <= MAXPATHLEN &&	/* "ed.hup" + '/' */
1390	    (hup = (char *) malloc(n + 10)) != NULL) {
1391		strcpy(hup, s);
1392		if (hup[n - 1] != '/')
1393			hup[n] = '/', hup[n+1] = '\0';
1394		strcat(hup, "ed.hup");
1395		write_file(hup, "w", 1, addr_last);
1396	}
1397	quit(2);
1398}
1399
1400
1401void
1402handle_int(signo)
1403	int signo;
1404{
1405	if (!sigactive)
1406		quit(1);
1407	sigflags &= ~(1 << (signo - 1));
1408#ifdef _POSIX_SOURCE
1409	siglongjmp(env, -1);
1410#else
1411	longjmp(env, -1);
1412#endif
1413}
1414
1415
1416int cols = 72;				/* wrap column */
1417
1418void
1419handle_winch(signo)
1420	int signo;
1421{
1422	struct winsize ws;		/* window size structure */
1423
1424	sigflags &= ~(1 << (signo - 1));
1425	if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1426		if (ws.ws_row > 2) rows = ws.ws_row - 2;
1427		if (ws.ws_col > 8) cols = ws.ws_col - 8;
1428	}
1429}
1430
1431
1432/* is_legal_filename: return a legal filename */
1433int
1434is_legal_filename(s)
1435	char *s;
1436{
1437	if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1438		sprintf(errmsg, "shell access restricted");
1439		return 0;
1440	}
1441	return 1;
1442}
1443