main.c revision 50471 
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 char * const copyright =
31"@(#) Copyright (c) 1993 Andrew Moore, Talke Studio. \n\
32 All rights reserved.\n";
33#endif /* not lint */
34
35#ifndef lint
36#if 0
37static char * const rcsid = "@(#)main.c,v 1.1 1994/02/01 00:34:42 alm Exp";
38#else
39static char * const rcsid =
40  "$FreeBSD: head/bin/ed/main.c 50471 1999-08-27 23:15:48Z peter $";
41#endif
42#endif /* not lint */
43
44/*
45 * CREDITS
46 *
47 *	This program is based on the editor algorithm described in
48 *	Brian W. Kernighan and P. J. Plauger's book "Software Tools
49 *	in Pascal," Addison-Wesley, 1981.
50 *
51 *	The buffering algorithm is attributed to Rodney Ruddock of
52 *	the University of Guelph, Guelph, Ontario.
53 *
54 *	The cbc.c encryption code is adapted from
55 *	the bdes program by Matt Bishop of Dartmouth College,
56 *	Hanover, NH.
57 *
58 */
59
60#include <sys/ioctl.h>
61#include <sys/wait.h>
62#include <ctype.h>
63#include <locale.h>
64#include <pwd.h>
65#include <setjmp.h>
66
67#include "ed.h"
68
69
70#ifdef _POSIX_SOURCE
71sigjmp_buf env;
72#else
73jmp_buf env;
74#endif
75
76/* static buffers */
77char stdinbuf[1];		/* stdin buffer */
78char *shcmd;			/* shell command buffer */
79int shcmdsz;			/* shell command buffer size */
80int shcmdi;			/* shell command buffer index */
81char *ibuf;			/* ed command-line buffer */
82int ibufsz;			/* ed command-line buffer size */
83char *ibufp;			/* pointer to ed command-line buffer */
84
85/* global flags */
86int des = 0;			/* if set, use crypt(3) for i/o */
87int garrulous = 0;		/* if set, print all error messages */
88int isbinary;			/* if set, buffer contains ASCII NULs */
89int isglobal;			/* if set, doing a global command */
90int modified;			/* if set, buffer modified since last write */
91int mutex = 0;			/* if set, signals set "sigflags" */
92int red = 0;			/* if set, restrict shell/directory access */
93int scripted = 0;		/* if set, suppress diagnostics */
94int sigflags = 0;		/* if set, signals received while mutex set */
95int sigactive = 0;		/* if set, signal handlers are enabled */
96
97char old_filename[MAXPATHLEN + 1] = "";	/* default filename */
98long current_addr;		/* current address in editor buffer */
99long addr_last;			/* last address in editor buffer */
100int lineno;			/* script line number */
101char *prompt;			/* command-line prompt */
102char *dps = "*";		/* default command-line prompt */
103
104char *usage = "usage: %s [-] [-sx] [-p string] [name]\n";
105
106/* ed: line editor */
107int
108main(argc, argv)
109	int argc;
110	char **argv;
111{
112	int c, n;
113	long status = 0;
114#if __GNUC__
115	/* Avoid longjmp clobbering */
116	(void) &argc;
117	(void) &argv;
118#endif
119
120	(void)setlocale(LC_ALL, "");
121
122	red = (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
123top:
124	while ((c = getopt(argc, argv, "p:sx")) != -1)
125		switch(c) {
126		case 'p':				/* set prompt */
127			prompt = optarg;
128			break;
129		case 's':				/* run script */
130			scripted = 1;
131			break;
132		case 'x':				/* use crypt */
133#ifdef DES
134			des = get_keyword();
135#else
136			fprintf(stderr, "crypt unavailable\n?\n");
137#endif
138			break;
139
140		default:
141			fprintf(stderr, usage, argv[0]);
142			exit(1);
143		}
144	argv += optind;
145	argc -= optind;
146	if (argc && **argv == '-') {
147		scripted = 1;
148		if (argc > 1) {
149			optind = 1;
150			goto top;
151		}
152		argv++;
153		argc--;
154	}
155	/* assert: reliable signals! */
156#ifdef SIGWINCH
157	handle_winch(SIGWINCH);
158	if (isatty(0)) signal(SIGWINCH, handle_winch);
159#endif
160	signal(SIGHUP, signal_hup);
161	signal(SIGQUIT, SIG_IGN);
162	signal(SIGINT, signal_int);
163#ifdef _POSIX_SOURCE
164	if ((status = sigsetjmp(env, 1)))
165#else
166	if ((status = setjmp(env)))
167#endif
168	{
169		fputs("\n?\n", stderr);
170		sprintf(errmsg, "interrupt");
171	} else {
172		init_buffers();
173		sigactive = 1;			/* enable signal handlers */
174		if (argc && **argv && is_legal_filename(*argv)) {
175			if (read_file(*argv, 0) < 0 && !isatty(0))
176				quit(2);
177			else if (**argv != '!')
178				strcpy(old_filename, *argv);
179		} else if (argc) {
180			fputs("?\n", stderr);
181			if (**argv == '\0')
182				sprintf(errmsg, "invalid filename");
183			if (!isatty(0))
184				quit(2);
185		}
186	}
187	for (;;) {
188		if (status < 0 && garrulous)
189			fprintf(stderr, "%s\n", errmsg);
190		if (prompt) {
191			printf("%s", prompt);
192			fflush(stdout);
193		}
194		if ((n = get_tty_line()) < 0) {
195			status = ERR;
196			continue;
197		} else if (n == 0) {
198			if (modified && !scripted) {
199				fputs("?\n", stderr);
200				sprintf(errmsg, "warning: file modified");
201				if (!isatty(0)) {
202					fprintf(stderr, garrulous ?
203					    "script, line %d: %s\n" :
204					    "", lineno, errmsg);
205					quit(2);
206				}
207				clearerr(stdin);
208				modified = 0;
209				status = EMOD;
210				continue;
211			} else
212				quit(0);
213		} else if (ibuf[n - 1] != '\n') {
214			/* discard line */
215			sprintf(errmsg, "unexpected end-of-file");
216			clearerr(stdin);
217			status = ERR;
218			continue;
219		}
220		isglobal = 0;
221		if ((status = extract_addr_range()) >= 0 &&
222		    (status = exec_command()) >= 0)
223			if (!status ||
224			    (status = display_lines(current_addr, current_addr,
225			        status)) >= 0)
226				continue;
227		switch (status) {
228		case EOF:
229			quit(0);
230		case EMOD:
231			modified = 0;
232			fputs("?\n", stderr);		/* give warning */
233			sprintf(errmsg, "warning: file modified");
234			if (!isatty(0)) {
235				fprintf(stderr, garrulous ?
236				    "script, line %d: %s\n" :
237				    "", lineno, errmsg);
238				quit(2);
239			}
240			break;
241		case FATAL:
242			if (!isatty(0))
243				fprintf(stderr, garrulous ?
244				    "script, line %d: %s\n" : "",
245				    lineno, errmsg);
246			else
247				fprintf(stderr, garrulous ? "%s\n" : "",
248				    errmsg);
249			quit(3);
250		default:
251			fputs("?\n", stderr);
252			if (!isatty(0)) {
253				fprintf(stderr, garrulous ?
254				    "script, line %d: %s\n" : "",
255				    lineno, errmsg);
256				quit(2);
257			}
258			break;
259		}
260	}
261	/*NOTREACHED*/
262}
263
264long first_addr, second_addr, addr_cnt;
265
266/* extract_addr_range: get line addresses from the command buffer until an
267   illegal address is seen; return status */
268int
269extract_addr_range()
270{
271	long addr;
272
273	addr_cnt = 0;
274	first_addr = second_addr = current_addr;
275	while ((addr = next_addr()) >= 0) {
276		addr_cnt++;
277		first_addr = second_addr;
278		second_addr = addr;
279		if (*ibufp != ',' && *ibufp != ';')
280			break;
281		else if (*ibufp++ == ';')
282			current_addr = addr;
283	}
284	if ((addr_cnt = min(addr_cnt, 2)) == 1 || second_addr != addr)
285		first_addr = second_addr;
286	return (addr == ERR) ? ERR : 0;
287}
288
289
290#define SKIP_BLANKS() while (isspace((unsigned char)*ibufp) && *ibufp != '\n') ibufp++
291
292#define MUST_BE_FIRST() \
293	if (!first) { sprintf(errmsg, "invalid address"); return ERR; }
294
295/*  next_addr: return the next line address in the command buffer */
296long
297next_addr()
298{
299	char *hd;
300	long addr = current_addr;
301	long n;
302	int first = 1;
303	int c;
304
305	SKIP_BLANKS();
306	for (hd = ibufp;; first = 0)
307		switch (c = *ibufp) {
308		case '+':
309		case '\t':
310		case ' ':
311		case '-':
312		case '^':
313			ibufp++;
314			SKIP_BLANKS();
315			if (isdigit((unsigned char)*ibufp)) {
316				STRTOL(n, ibufp);
317				addr += (c == '-' || c == '^') ? -n : n;
318			} else if (!isspace((unsigned char)c))
319				addr += (c == '-' || c == '^') ? -1 : 1;
320			break;
321		case '0': case '1': case '2':
322		case '3': case '4': case '5':
323		case '6': case '7': case '8': case '9':
324			MUST_BE_FIRST();
325			STRTOL(addr, ibufp);
326			break;
327		case '.':
328		case '$':
329			MUST_BE_FIRST();
330			ibufp++;
331			addr = (c == '.') ? current_addr : addr_last;
332			break;
333		case '/':
334		case '?':
335			MUST_BE_FIRST();
336			if ((addr = get_matching_node_addr(
337			    get_compiled_pattern(), c == '/')) < 0)
338				return ERR;
339			else if (c == *ibufp)
340				ibufp++;
341			break;
342		case '\'':
343			MUST_BE_FIRST();
344			ibufp++;
345			if ((addr = get_marked_node_addr(*ibufp++)) < 0)
346				return ERR;
347			break;
348		case '%':
349		case ',':
350		case ';':
351			if (first) {
352				ibufp++;
353				addr_cnt++;
354				second_addr = (c == ';') ? current_addr : 1;
355				addr = addr_last;
356				break;
357			}
358			/* FALL THROUGH */
359		default:
360			if (ibufp == hd)
361				return EOF;
362			else if (addr < 0 || addr_last < addr) {
363				sprintf(errmsg, "invalid address");
364				return ERR;
365			} else
366				return addr;
367		}
368	/* NOTREACHED */
369}
370
371
372#ifdef BACKWARDS
373/* GET_THIRD_ADDR: get a legal address from the command buffer */
374#define GET_THIRD_ADDR(addr) \
375{ \
376	long ol1, ol2; \
377\
378	ol1 = first_addr, ol2 = second_addr; \
379	if (extract_addr_range() < 0) \
380		return ERR; \
381	else if (addr_cnt == 0) { \
382		sprintf(errmsg, "destination expected"); \
383		return ERR; \
384	} else if (second_addr < 0 || addr_last < second_addr) { \
385		sprintf(errmsg, "invalid address"); \
386		return ERR; \
387	} \
388	addr = second_addr; \
389	first_addr = ol1, second_addr = ol2; \
390}
391#else	/* BACKWARDS */
392/* GET_THIRD_ADDR: get a legal address from the command buffer */
393#define GET_THIRD_ADDR(addr) \
394{ \
395	long ol1, ol2; \
396\
397	ol1 = first_addr, ol2 = second_addr; \
398	if (extract_addr_range() < 0) \
399		return ERR; \
400	if (second_addr < 0 || addr_last < second_addr) { \
401		sprintf(errmsg, "invalid address"); \
402		return ERR; \
403	} \
404	addr = second_addr; \
405	first_addr = ol1, second_addr = ol2; \
406}
407#endif
408
409
410/* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
411#define GET_COMMAND_SUFFIX() { \
412	int done = 0; \
413	do { \
414		switch(*ibufp) { \
415		case 'p': \
416			gflag |= GPR, ibufp++; \
417			break; \
418		case 'l': \
419			gflag |= GLS, ibufp++; \
420			break; \
421		case 'n': \
422			gflag |= GNP, ibufp++; \
423			break; \
424		default: \
425			done++; \
426		} \
427	} while (!done); \
428	if (*ibufp++ != '\n') { \
429		sprintf(errmsg, "invalid command suffix"); \
430		return ERR; \
431	} \
432}
433
434
435/* sflags */
436#define SGG 001		/* complement previous global substitute suffix */
437#define SGP 002		/* complement previous print suffix */
438#define SGR 004		/* use last regex instead of last pat */
439#define SGF 010		/* repeat last substitution */
440
441int patlock = 0;	/* if set, pattern not freed by get_compiled_pattern() */
442
443long rows = 22;		/* scroll length: ws_row - 2 */
444
445/* exec_command: execute the next command in command buffer; return print
446   request, if any */
447int
448exec_command()
449{
450	extern long u_current_addr;
451	extern long u_addr_last;
452
453	static pattern_t *pat = NULL;
454	static int sgflag = 0;
455	static long sgnum = 0;
456
457	pattern_t *tpat;
458	char *fnp;
459	int gflag = 0;
460	int sflags = 0;
461	long addr = 0;
462	int n = 0;
463	int c;
464
465	SKIP_BLANKS();
466	switch(c = *ibufp++) {
467	case 'a':
468		GET_COMMAND_SUFFIX();
469		if (!isglobal) clear_undo_stack();
470		if (append_lines(second_addr) < 0)
471			return ERR;
472		break;
473	case 'c':
474		if (check_addr_range(current_addr, current_addr) < 0)
475			return ERR;
476		GET_COMMAND_SUFFIX();
477		if (!isglobal) clear_undo_stack();
478		if (delete_lines(first_addr, second_addr) < 0 ||
479		    append_lines(current_addr) < 0)
480			return ERR;
481		break;
482	case 'd':
483		if (check_addr_range(current_addr, current_addr) < 0)
484			return ERR;
485		GET_COMMAND_SUFFIX();
486		if (!isglobal) clear_undo_stack();
487		if (delete_lines(first_addr, second_addr) < 0)
488			return ERR;
489		else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
490			current_addr = addr;
491		break;
492	case 'e':
493		if (modified && !scripted)
494			return EMOD;
495		/* fall through */
496	case 'E':
497		if (addr_cnt > 0) {
498			sprintf(errmsg, "unexpected address");
499			return ERR;
500		} else if (!isspace((unsigned char)*ibufp)) {
501			sprintf(errmsg, "unexpected command suffix");
502			return ERR;
503		} else if ((fnp = get_filename()) == NULL)
504			return ERR;
505		GET_COMMAND_SUFFIX();
506		if (delete_lines(1, addr_last) < 0)
507			return ERR;
508		clear_undo_stack();
509		if (close_sbuf() < 0)
510			return ERR;
511		else if (open_sbuf() < 0)
512			return FATAL;
513		if (*fnp && *fnp != '!') strcpy(old_filename, fnp);
514#ifdef BACKWARDS
515		if (*fnp == '\0' && *old_filename == '\0') {
516			sprintf(errmsg, "no current filename");
517			return ERR;
518		}
519#endif
520		if (read_file(*fnp ? fnp : old_filename, 0) < 0)
521			return ERR;
522		clear_undo_stack();
523		modified = 0;
524		u_current_addr = u_addr_last = -1;
525		break;
526	case 'f':
527		if (addr_cnt > 0) {
528			sprintf(errmsg, "unexpected address");
529			return ERR;
530		} else if (!isspace((unsigned char)*ibufp)) {
531			sprintf(errmsg, "unexpected command suffix");
532			return ERR;
533		} else if ((fnp = get_filename()) == NULL)
534			return ERR;
535		else if (*fnp == '!') {
536			sprintf(errmsg, "invalid redirection");
537			return ERR;
538		}
539		GET_COMMAND_SUFFIX();
540		if (*fnp) strcpy(old_filename, fnp);
541		printf("%s\n", strip_escapes(old_filename));
542		break;
543	case 'g':
544	case 'v':
545	case 'G':
546	case 'V':
547		if (isglobal) {
548			sprintf(errmsg, "cannot nest global commands");
549			return ERR;
550		} else if (check_addr_range(1, addr_last) < 0)
551			return ERR;
552		else if (build_active_list(c == 'g' || c == 'G') < 0)
553			return ERR;
554		else if ((n = (c == 'G' || c == 'V')))
555			GET_COMMAND_SUFFIX();
556		isglobal++;
557		if (exec_global(n, gflag) < 0)
558			return ERR;
559		break;
560	case 'h':
561		if (addr_cnt > 0) {
562			sprintf(errmsg, "unexpected address");
563			return ERR;
564		}
565		GET_COMMAND_SUFFIX();
566		if (*errmsg) fprintf(stderr, "%s\n", errmsg);
567		break;
568	case 'H':
569		if (addr_cnt > 0) {
570			sprintf(errmsg, "unexpected address");
571			return ERR;
572		}
573		GET_COMMAND_SUFFIX();
574		if ((garrulous = 1 - garrulous) && *errmsg)
575			fprintf(stderr, "%s\n", errmsg);
576		break;
577	case 'i':
578		if (second_addr == 0) {
579			sprintf(errmsg, "invalid address");
580			return ERR;
581		}
582		GET_COMMAND_SUFFIX();
583		if (!isglobal) clear_undo_stack();
584		if (append_lines(second_addr - 1) < 0)
585			return ERR;
586		break;
587	case 'j':
588		if (check_addr_range(current_addr, current_addr + 1) < 0)
589			return ERR;
590		GET_COMMAND_SUFFIX();
591		if (!isglobal) clear_undo_stack();
592		if (first_addr != second_addr &&
593		    join_lines(first_addr, second_addr) < 0)
594			return ERR;
595		break;
596	case 'k':
597		c = *ibufp++;
598		if (second_addr == 0) {
599			sprintf(errmsg, "invalid address");
600			return ERR;
601		}
602		GET_COMMAND_SUFFIX();
603		if (mark_line_node(get_addressed_line_node(second_addr), c) < 0)
604			return ERR;
605		break;
606	case 'l':
607		if (check_addr_range(current_addr, current_addr) < 0)
608			return ERR;
609		GET_COMMAND_SUFFIX();
610		if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
611			return ERR;
612		gflag = 0;
613		break;
614	case 'm':
615		if (check_addr_range(current_addr, current_addr) < 0)
616			return ERR;
617		GET_THIRD_ADDR(addr);
618		if (first_addr <= addr && addr < second_addr) {
619			sprintf(errmsg, "invalid destination");
620			return ERR;
621		}
622		GET_COMMAND_SUFFIX();
623		if (!isglobal) clear_undo_stack();
624		if (move_lines(addr) < 0)
625			return ERR;
626		break;
627	case 'n':
628		if (check_addr_range(current_addr, current_addr) < 0)
629			return ERR;
630		GET_COMMAND_SUFFIX();
631		if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
632			return ERR;
633		gflag = 0;
634		break;
635	case 'p':
636		if (check_addr_range(current_addr, current_addr) < 0)
637			return ERR;
638		GET_COMMAND_SUFFIX();
639		if (display_lines(first_addr, second_addr, gflag | GPR) < 0)
640			return ERR;
641		gflag = 0;
642		break;
643	case 'P':
644		if (addr_cnt > 0) {
645			sprintf(errmsg, "unexpected address");
646			return ERR;
647		}
648		GET_COMMAND_SUFFIX();
649		prompt = prompt ? NULL : optarg ? optarg : dps;
650		break;
651	case 'q':
652	case 'Q':
653		if (addr_cnt > 0) {
654			sprintf(errmsg, "unexpected address");
655			return ERR;
656		}
657		GET_COMMAND_SUFFIX();
658		gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
659		break;
660	case 'r':
661		if (!isspace((unsigned char)*ibufp)) {
662			sprintf(errmsg, "unexpected command suffix");
663			return ERR;
664		} else if (addr_cnt == 0)
665			second_addr = addr_last;
666		if ((fnp = get_filename()) == NULL)
667			return ERR;
668		GET_COMMAND_SUFFIX();
669		if (!isglobal) clear_undo_stack();
670		if (*old_filename == '\0' && *fnp != '!')
671			strcpy(old_filename, fnp);
672#ifdef BACKWARDS
673		if (*fnp == '\0' && *old_filename == '\0') {
674			sprintf(errmsg, "no current filename");
675			return ERR;
676		}
677#endif
678		if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
679			return ERR;
680		else if (addr && addr != addr_last)
681			modified = 1;
682		break;
683	case 's':
684		do {
685			switch(*ibufp) {
686			case '\n':
687				sflags |=SGF;
688				break;
689			case 'g':
690				sflags |= SGG;
691				ibufp++;
692				break;
693			case 'p':
694				sflags |= SGP;
695				ibufp++;
696				break;
697			case 'r':
698				sflags |= SGR;
699				ibufp++;
700				break;
701			case '0': case '1': case '2': case '3': case '4':
702			case '5': case '6': case '7': case '8': case '9':
703				STRTOL(sgnum, ibufp);
704				sflags |= SGF;
705				sgflag &= ~GSG;		/* override GSG */
706				break;
707			default:
708				if (sflags) {
709					sprintf(errmsg, "invalid command suffix");
710					return ERR;
711				}
712			}
713		} while (sflags && *ibufp != '\n');
714		if (sflags && !pat) {
715			sprintf(errmsg, "no previous substitution");
716			return ERR;
717		} else if (sflags & SGG)
718			sgnum = 0;		/* override numeric arg */
719		if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
720			sprintf(errmsg, "invalid pattern delimiter");
721			return ERR;
722		}
723		tpat = pat;
724		SPL1();
725		if ((!sflags || (sflags & SGR)) &&
726		    (tpat = get_compiled_pattern()) == NULL) {
727		 	SPL0();
728			return ERR;
729		} else if (tpat != pat) {
730			if (pat) {
731				regfree(pat);
732				free(pat);
733			}
734			pat = tpat;
735			patlock = 1;		/* reserve pattern */
736		}
737		SPL0();
738		if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
739			return ERR;
740		else if (isglobal)
741			sgflag |= GLB;
742		else
743			sgflag &= ~GLB;
744		if (sflags & SGG)
745			sgflag ^= GSG;
746		if (sflags & SGP)
747			sgflag ^= GPR, sgflag &= ~(GLS | GNP);
748		do {
749			switch(*ibufp) {
750			case 'p':
751				sgflag |= GPR, ibufp++;
752				break;
753			case 'l':
754				sgflag |= GLS, ibufp++;
755				break;
756			case 'n':
757				sgflag |= GNP, ibufp++;
758				break;
759			default:
760				n++;
761			}
762		} while (!n);
763		if (check_addr_range(current_addr, current_addr) < 0)
764			return ERR;
765		GET_COMMAND_SUFFIX();
766		if (!isglobal) clear_undo_stack();
767		if (search_and_replace(pat, sgflag, sgnum) < 0)
768			return ERR;
769		break;
770	case 't':
771		if (check_addr_range(current_addr, current_addr) < 0)
772			return ERR;
773		GET_THIRD_ADDR(addr);
774		GET_COMMAND_SUFFIX();
775		if (!isglobal) clear_undo_stack();
776		if (copy_lines(addr) < 0)
777			return ERR;
778		break;
779	case 'u':
780		if (addr_cnt > 0) {
781			sprintf(errmsg, "unexpected address");
782			return ERR;
783		}
784		GET_COMMAND_SUFFIX();
785		if (pop_undo_stack() < 0)
786			return ERR;
787		break;
788	case 'w':
789	case 'W':
790		if ((n = *ibufp) == 'q' || n == 'Q') {
791			gflag = EOF;
792			ibufp++;
793		}
794		if (!isspace((unsigned char)*ibufp)) {
795			sprintf(errmsg, "unexpected command suffix");
796			return ERR;
797		} else if ((fnp = get_filename()) == NULL)
798			return ERR;
799		if (addr_cnt == 0 && !addr_last)
800			first_addr = second_addr = 0;
801		else if (check_addr_range(1, addr_last) < 0)
802			return ERR;
803		GET_COMMAND_SUFFIX();
804		if (*old_filename == '\0' && *fnp != '!')
805			strcpy(old_filename, fnp);
806#ifdef BACKWARDS
807		if (*fnp == '\0' && *old_filename == '\0') {
808			sprintf(errmsg, "no current filename");
809			return ERR;
810		}
811#endif
812		if ((addr = write_file(*fnp ? fnp : old_filename,
813		    (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
814			return ERR;
815		else if (addr == addr_last)
816			modified = 0;
817		else if (modified && !scripted && n == 'q')
818			gflag = EMOD;
819		break;
820	case 'x':
821		if (addr_cnt > 0) {
822			sprintf(errmsg, "unexpected address");
823			return ERR;
824		}
825		GET_COMMAND_SUFFIX();
826#ifdef DES
827		des = get_keyword();
828#else
829		sprintf(errmsg, "crypt unavailable");
830		return ERR;
831#endif
832		break;
833	case 'z':
834#ifdef BACKWARDS
835		if (check_addr_range(first_addr = 1, current_addr + 1) < 0)
836#else
837		if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0)
838#endif
839			return ERR;
840		else if ('0' < *ibufp && *ibufp <= '9')
841			STRTOL(rows, ibufp);
842		GET_COMMAND_SUFFIX();
843		if (display_lines(second_addr, min(addr_last,
844		    second_addr + rows), gflag) < 0)
845			return ERR;
846		gflag = 0;
847		break;
848	case '=':
849		GET_COMMAND_SUFFIX();
850		printf("%ld\n", addr_cnt ? second_addr : addr_last);
851		break;
852	case '!':
853		if (addr_cnt > 0) {
854			sprintf(errmsg, "unexpected address");
855			return ERR;
856		} else if ((sflags = get_shell_command()) < 0)
857			return ERR;
858		GET_COMMAND_SUFFIX();
859		if (sflags) printf("%s\n", shcmd + 1);
860		system(shcmd + 1);
861		if (!scripted) printf("!\n");
862		break;
863	case '\n':
864#ifdef BACKWARDS
865		if (check_addr_range(first_addr = 1, current_addr + 1) < 0
866#else
867		if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0
868#endif
869		 || display_lines(second_addr, second_addr, 0) < 0)
870			return ERR;
871		break;
872	default:
873		sprintf(errmsg, "unknown command");
874		return ERR;
875	}
876	return gflag;
877}
878
879
880/* check_addr_range: return status of address range check */
881int
882check_addr_range(n, m)
883	long n, m;
884{
885	if (addr_cnt == 0) {
886		first_addr = n;
887		second_addr = m;
888	}
889	if (first_addr > second_addr || 1 > first_addr ||
890	    second_addr > addr_last) {
891		sprintf(errmsg, "invalid address");
892		return ERR;
893	}
894	return 0;
895}
896
897
898/* get_matching_node_addr: return the address of the next line matching a
899   pattern in a given direction.  wrap around begin/end of editor buffer if
900   necessary */
901long
902get_matching_node_addr(pat, dir)
903	pattern_t *pat;
904	int dir;
905{
906	char *s;
907	long n = current_addr;
908	line_t *lp;
909
910	if (!pat) return ERR;
911	do {
912	       if ((n = dir ? INC_MOD(n, addr_last) : DEC_MOD(n, addr_last))) {
913			lp = get_addressed_line_node(n);
914			if ((s = get_sbuf_line(lp)) == NULL)
915				return ERR;
916			if (isbinary)
917				NUL_TO_NEWLINE(s, lp->len);
918			if (!regexec(pat, s, 0, NULL, 0))
919				return n;
920	       }
921	} while (n != current_addr);
922	sprintf(errmsg, "no match");
923	return  ERR;
924}
925
926
927/* get_filename: return pointer to copy of filename in the command buffer */
928char *
929get_filename()
930{
931	static char *file = NULL;
932	static int filesz = 0;
933
934	int n;
935
936	if (*ibufp != '\n') {
937		SKIP_BLANKS();
938		if (*ibufp == '\n') {
939			sprintf(errmsg, "invalid filename");
940			return NULL;
941		} else if ((ibufp = get_extended_line(&n, 1)) == NULL)
942			return NULL;
943		else if (*ibufp == '!') {
944			ibufp++;
945			if ((n = get_shell_command()) < 0)
946				return NULL;
947			if (n) printf("%s\n", shcmd + 1);
948			return shcmd;
949		} else if (n - 1 > MAXPATHLEN) {
950			sprintf(errmsg, "filename too long");
951			return  NULL;
952		}
953	}
954#ifndef BACKWARDS
955	else if (*old_filename == '\0') {
956		sprintf(errmsg, "no current filename");
957		return  NULL;
958	}
959#endif
960	REALLOC(file, filesz, MAXPATHLEN + 1, 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()
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		sprintf(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				sprintf(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				sprintf(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(n)
1038	long n;
1039{
1040	int l;
1041	char *lp = ibuf;
1042	char *eot;
1043	undo_t *up = NULL;
1044
1045	for (current_addr = n;;) {
1046		if (!isglobal) {
1047			if ((l = get_tty_line()) < 0)
1048				return ERR;
1049			else if (l == 0 || ibuf[l - 1] != '\n') {
1050				clearerr(stdin);
1051				return  l ? EOF : 0;
1052			}
1053			lp = ibuf;
1054		} else if (*(lp = ibufp) == '\0')
1055			return 0;
1056		else {
1057			while (*ibufp++ != '\n')
1058				;
1059			l = ibufp - lp;
1060		}
1061		if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1062			return 0;
1063		}
1064		eot = lp + l;
1065		SPL1();
1066		do {
1067			if ((lp = put_sbuf_line(lp)) == NULL) {
1068				SPL0();
1069				return ERR;
1070			} else if (up)
1071				up->t = get_addressed_line_node(current_addr);
1072			else if ((up = push_undo_stack(UADD, current_addr,
1073			    current_addr)) == NULL) {
1074				SPL0();
1075				return ERR;
1076			}
1077		} while (lp != eot);
1078		modified = 1;
1079		SPL0();
1080	}
1081	/* NOTREACHED */
1082}
1083
1084
1085/* join_lines: replace a range of lines with the joined text of those lines */
1086int
1087join_lines(from, to)
1088	long from;
1089	long to;
1090{
1091	static char *buf = NULL;
1092	static int n;
1093
1094	char *s;
1095	int size = 0;
1096	line_t *bp, *ep;
1097
1098	ep = get_addressed_line_node(INC_MOD(to, addr_last));
1099	bp = get_addressed_line_node(from);
1100	for (; bp != ep; bp = bp->q_forw) {
1101		if ((s = get_sbuf_line(bp)) == NULL)
1102			return ERR;
1103		REALLOC(buf, n, size + bp->len, ERR);
1104		memcpy(buf + size, s, bp->len);
1105		size += bp->len;
1106	}
1107	REALLOC(buf, n, size + 2, ERR);
1108	memcpy(buf + size, "\n", 2);
1109	if (delete_lines(from, to) < 0)
1110		return ERR;
1111	current_addr = from - 1;
1112	SPL1();
1113	if (put_sbuf_line(buf) == NULL ||
1114	    push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1115		SPL0();
1116		return ERR;
1117	}
1118	modified = 1;
1119	SPL0();
1120	return 0;
1121}
1122
1123
1124/* move_lines: move a range of lines */
1125int
1126move_lines(addr)
1127	long addr;
1128{
1129	line_t *b1, *a1, *b2, *a2;
1130	long n = INC_MOD(second_addr, addr_last);
1131	long p = first_addr - 1;
1132	int done = (addr == first_addr - 1 || addr == second_addr);
1133
1134	SPL1();
1135	if (done) {
1136		a2 = get_addressed_line_node(n);
1137		b2 = get_addressed_line_node(p);
1138		current_addr = second_addr;
1139	} else if (push_undo_stack(UMOV, p, n) == NULL ||
1140	    push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1141		SPL0();
1142		return ERR;
1143	} else {
1144		a1 = get_addressed_line_node(n);
1145		if (addr < first_addr) {
1146			b1 = get_addressed_line_node(p);
1147			b2 = get_addressed_line_node(addr);
1148					/* this get_addressed_line_node last! */
1149		} else {
1150			b2 = get_addressed_line_node(addr);
1151			b1 = get_addressed_line_node(p);
1152					/* this get_addressed_line_node last! */
1153		}
1154		a2 = b2->q_forw;
1155		REQUE(b2, b1->q_forw);
1156		REQUE(a1->q_back, a2);
1157		REQUE(b1, a1);
1158		current_addr = addr + ((addr < first_addr) ?
1159		    second_addr - first_addr + 1 : 0);
1160	}
1161	if (isglobal)
1162		unset_active_nodes(b2->q_forw, a2);
1163	modified = 1;
1164	SPL0();
1165	return 0;
1166}
1167
1168
1169/* copy_lines: copy a range of lines; return status */
1170int
1171copy_lines(addr)
1172	long addr;
1173{
1174	line_t *lp, *np = get_addressed_line_node(first_addr);
1175	undo_t *up = NULL;
1176	long n = second_addr - first_addr + 1;
1177	long m = 0;
1178
1179	current_addr = addr;
1180	if (first_addr <= addr && addr < second_addr) {
1181		n =  addr - first_addr + 1;
1182		m = second_addr - addr;
1183	}
1184	for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1185		for (; n-- > 0; np = np->q_forw) {
1186			SPL1();
1187			if ((lp = dup_line_node(np)) == NULL) {
1188				SPL0();
1189				return ERR;
1190			}
1191			add_line_node(lp);
1192			if (up)
1193				up->t = lp;
1194			else if ((up = push_undo_stack(UADD, current_addr,
1195			    current_addr)) == NULL) {
1196				SPL0();
1197				return ERR;
1198			}
1199			modified = 1;
1200			SPL0();
1201		}
1202	return 0;
1203}
1204
1205
1206/* delete_lines: delete a range of lines */
1207int
1208delete_lines(from, to)
1209	long from, to;
1210{
1211	line_t *n, *p;
1212
1213	SPL1();
1214	if (push_undo_stack(UDEL, from, to) == NULL) {
1215		SPL0();
1216		return ERR;
1217	}
1218	n = get_addressed_line_node(INC_MOD(to, addr_last));
1219	p = get_addressed_line_node(from - 1);
1220					/* this get_addressed_line_node last! */
1221	if (isglobal)
1222		unset_active_nodes(p->q_forw, n);
1223	REQUE(p, n);
1224	addr_last -= to - from + 1;
1225	current_addr = from - 1;
1226	modified = 1;
1227	SPL0();
1228	return 0;
1229}
1230
1231
1232/* display_lines: print a range of lines to stdout */
1233int
1234display_lines(from, to, gflag)
1235	long from;
1236	long to;
1237	int gflag;
1238{
1239	line_t *bp;
1240	line_t *ep;
1241	char *s;
1242
1243	if (!from) {
1244		sprintf(errmsg, "invalid address");
1245		return ERR;
1246	}
1247	ep = get_addressed_line_node(INC_MOD(to, addr_last));
1248	bp = get_addressed_line_node(from);
1249	for (; bp != ep; bp = bp->q_forw) {
1250		if ((s = get_sbuf_line(bp)) == NULL)
1251			return ERR;
1252		if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1253			return ERR;
1254	}
1255	return 0;
1256}
1257
1258
1259#define MAXMARK 26			/* max number of marks */
1260
1261line_t	*mark[MAXMARK];			/* line markers */
1262int markno;				/* line marker count */
1263
1264/* mark_line_node: set a line node mark */
1265int
1266mark_line_node(lp, n)
1267	line_t *lp;
1268	int n;
1269{
1270	if (!islower((unsigned char)n)) {
1271		sprintf(errmsg, "invalid mark character");
1272		return ERR;
1273	} else if (mark[n - 'a'] == NULL)
1274		markno++;
1275	mark[n - 'a'] = lp;
1276	return 0;
1277}
1278
1279
1280/* get_marked_node_addr: return address of a marked line */
1281long
1282get_marked_node_addr(n)
1283	int n;
1284{
1285	if (!islower((unsigned char)n)) {
1286		sprintf(errmsg, "invalid mark character");
1287		return ERR;
1288	}
1289	return get_line_node_addr(mark[n - 'a']);
1290}
1291
1292
1293/* unmark_line_node: clear line node mark */
1294void
1295unmark_line_node(lp)
1296	line_t *lp;
1297{
1298	int i;
1299
1300	for (i = 0; markno && i < MAXMARK; i++)
1301		if (mark[i] == lp) {
1302			mark[i] = NULL;
1303			markno--;
1304		}
1305}
1306
1307
1308/* dup_line_node: return a pointer to a copy of a line node */
1309line_t *
1310dup_line_node(lp)
1311	line_t *lp;
1312{
1313	line_t *np;
1314
1315	if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1316		fprintf(stderr, "%s\n", strerror(errno));
1317		sprintf(errmsg, "out of memory");
1318		return NULL;
1319	}
1320	np->seek = lp->seek;
1321	np->len = lp->len;
1322	return np;
1323}
1324
1325
1326/* has_trailing_escape:  return the parity of escapes preceding a character
1327   in a string */
1328int
1329has_trailing_escape(s, t)
1330	char *s;
1331	char *t;
1332{
1333    return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1334}
1335
1336
1337/* strip_escapes: return copy of escaped string of at most length MAXPATHLEN */
1338char *
1339strip_escapes(s)
1340	char *s;
1341{
1342	static char *file = NULL;
1343	static int filesz = 0;
1344
1345	int i = 0;
1346
1347	REALLOC(file, filesz, MAXPATHLEN + 1, NULL);
1348	/* assert: no trailing escape */
1349	while ((file[i++] = (*s == '\\') ? *++s : *s))
1350		s++;
1351	return file;
1352}
1353
1354
1355void
1356signal_hup(signo)
1357	int signo;
1358{
1359	if (mutex)
1360		sigflags |= (1 << (signo - 1));
1361	else
1362		handle_hup(signo);
1363}
1364
1365
1366void
1367signal_int(signo)
1368	int signo;
1369{
1370	if (mutex)
1371		sigflags |= (1 << (signo - 1));
1372	else
1373		handle_int(signo);
1374}
1375
1376
1377void
1378handle_hup(signo)
1379	int signo;
1380{
1381	char *hup = NULL;		/* hup filename */
1382	char *s;
1383	int n;
1384
1385	if (!sigactive)
1386		quit(1);
1387	sigflags &= ~(1 << (signo - 1));
1388	if (addr_last && write_file("ed.hup", "w", 1, addr_last) < 0 &&
1389	    (s = getenv("HOME")) != NULL &&
1390	    (n = strlen(s)) + 8 <= MAXPATHLEN &&	/* "ed.hup" + '/' */
1391	    (hup = (char *) malloc(n + 10)) != NULL) {
1392		strcpy(hup, s);
1393		if (hup[n - 1] != '/')
1394			hup[n] = '/', hup[n+1] = '\0';
1395		strcat(hup, "ed.hup");
1396		write_file(hup, "w", 1, addr_last);
1397	}
1398	quit(2);
1399}
1400
1401
1402void
1403handle_int(signo)
1404	int signo;
1405{
1406	if (!sigactive)
1407		quit(1);
1408	sigflags &= ~(1 << (signo - 1));
1409#ifdef _POSIX_SOURCE
1410	siglongjmp(env, -1);
1411#else
1412	longjmp(env, -1);
1413#endif
1414}
1415
1416
1417int cols = 72;				/* wrap column */
1418
1419void
1420handle_winch(signo)
1421	int signo;
1422{
1423	int save_errno = errno;
1424
1425	struct winsize ws;		/* window size structure */
1426
1427	sigflags &= ~(1 << (signo - 1));
1428	if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1429		if (ws.ws_row > 2) rows = ws.ws_row - 2;
1430		if (ws.ws_col > 8) cols = ws.ws_col - 8;
1431	}
1432	errno = save_errno;
1433}
1434
1435
1436/* is_legal_filename: return a legal filename */
1437int
1438is_legal_filename(s)
1439	char *s;
1440{
1441	if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1442		sprintf(errmsg, "shell access restricted");
1443		return 0;
1444	}
1445	return 1;
1446}
1447