Merge from vendor branch DIFFUTILS:
[dragonfly.git] / bin / ed / main.c
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  * @(#) Copyright (c) 1993 Andrew Moore, Talke Studio. All rights reserved.
29  * @(#)main.c,v 1.1 1994/02/01 00:34:42 alm Exp
30  * $FreeBSD: src/bin/ed/main.c,v 1.14.2.4 2001/08/01 02:36:03 obrien Exp $
31  * $DragonFly: src/bin/ed/main.c,v 1.4 2004/03/19 17:47:48 cpressey Exp $
32  */
33
34 /*
35  * CREDITS
36  *
37  *      This program is based on the editor algorithm described in
38  *      Brian W. Kernighan and P. J. Plauger's book "Software Tools
39  *      in Pascal," Addison-Wesley, 1981.
40  *
41  *      The buffering algorithm is attributed to Rodney Ruddock of
42  *      the University of Guelph, Guelph, Ontario.
43  *
44  *      The cbc.c encryption code is adapted from
45  *      the bdes program by Matt Bishop of Dartmouth College,
46  *      Hanover, NH.
47  *
48  */
49
50 #include <sys/types.h>
51
52 #include <sys/ioctl.h>
53 #include <sys/wait.h>
54 #include <ctype.h>
55 #include <locale.h>
56 #include <pwd.h>
57 #include <setjmp.h>
58
59 #include "ed.h"
60
61
62 #ifdef _POSIX_SOURCE
63 sigjmp_buf env;
64 #else
65 jmp_buf env;
66 #endif
67
68 /* static buffers */
69 char stdinbuf[1];               /* stdin buffer */
70 char *shcmd;                    /* shell command buffer */
71 int shcmdsz;                    /* shell command buffer size */
72 int shcmdi;                     /* shell command buffer index */
73 char *ibuf;                     /* ed command-line buffer */
74 int ibufsz;                     /* ed command-line buffer size */
75 char *ibufp;                    /* pointer to ed command-line buffer */
76
77 /* global flags */
78 int des = 0;                    /* if set, use crypt(3) for i/o */
79 int garrulous = 0;              /* if set, print all error messages */
80 int isbinary;                   /* if set, buffer contains ASCII NULs */
81 int isglobal;                   /* if set, doing a global command */
82 int modified;                   /* if set, buffer modified since last write */
83 int mutex = 0;                  /* if set, signals set "sigflags" */
84 int red = 0;                    /* if set, restrict shell/directory access */
85 int scripted = 0;               /* if set, suppress diagnostics */
86 int sigflags = 0;               /* if set, signals received while mutex set */
87 int sigactive = 0;              /* if set, signal handlers are enabled */
88
89 char old_filename[PATH_MAX] = "";       /* default filename */
90 long current_addr;              /* current address in editor buffer */
91 long addr_last;                 /* last address in editor buffer */
92 int lineno;                     /* script line number */
93 const char *prompt;             /* command-line prompt */
94 const char *dps = "*";          /* default command-line prompt */
95
96 const char usage[] = "usage: %s [-] [-sx] [-p string] [name]\n";
97
98 /* ed: line editor */
99 int
100 main(int argc, char **argv)
101 {
102         int c, n;
103         long status = 0;
104 #if __GNUC__
105         /* Avoid longjmp clobbering */
106         (void) &argc;
107         (void) &argv;
108 #endif
109
110         (void)setlocale(LC_ALL, "");
111
112         red = (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
113 top:
114         while ((c = getopt(argc, argv, "p:sx")) != -1)
115                 switch(c) {
116                 case 'p':                               /* set prompt */
117                         prompt = optarg;
118                         break;
119                 case 's':                               /* run script */
120                         scripted = 1;
121                         break;
122                 case 'x':                               /* use crypt */
123 #ifdef DES
124                         des = get_keyword();
125 #else
126                         fprintf(stderr, "crypt unavailable\n?\n");
127 #endif
128                         break;
129
130                 default:
131                         fprintf(stderr, usage, argv[0]);
132                         exit(1);
133                 }
134         argv += optind;
135         argc -= optind;
136         if (argc && **argv == '-') {
137                 scripted = 1;
138                 if (argc > 1) {
139                         optind = 1;
140                         goto top;
141                 }
142                 argv++;
143                 argc--;
144         }
145         /* assert: reliable signals! */
146 #ifdef SIGWINCH
147         handle_winch(SIGWINCH);
148         if (isatty(0)) signal(SIGWINCH, handle_winch);
149 #endif
150         signal(SIGHUP, signal_hup);
151         signal(SIGQUIT, SIG_IGN);
152         signal(SIGINT, signal_int);
153 #ifdef _POSIX_SOURCE
154         if ((status = sigsetjmp(env, 1)))
155 #else
156         if ((status = setjmp(env)))
157 #endif
158         {
159                 fputs("\n?\n", stderr);
160                 sprintf(errmsg, "interrupt");
161         } else {
162                 init_buffers();
163                 sigactive = 1;                  /* enable signal handlers */
164                 if (argc && **argv && is_legal_filename(*argv)) {
165                         if (read_file(*argv, 0) < 0 && !isatty(0))
166                                 quit(2);
167                         else if (**argv != '!')
168                                 if (strlcpy(old_filename, *argv, sizeof(old_filename))
169                                     >= sizeof(old_filename))
170                                         quit(2);
171                 } else if (argc) {
172                         fputs("?\n", stderr);
173                         if (**argv == '\0')
174                                 sprintf(errmsg, "invalid filename");
175                         if (!isatty(0))
176                                 quit(2);
177                 }
178         }
179         for (;;) {
180                 if (status < 0 && garrulous)
181                         fprintf(stderr, "%s\n", errmsg);
182                 if (prompt) {
183                         printf("%s", prompt);
184                         fflush(stdout);
185                 }
186                 if ((n = get_tty_line()) < 0) {
187                         status = ERR;
188                         continue;
189                 } else if (n == 0) {
190                         if (modified && !scripted) {
191                                 fputs("?\n", stderr);
192                                 sprintf(errmsg, "warning: file modified");
193                                 if (!isatty(0)) {
194                                         fprintf(stderr, garrulous ?
195                                             "script, line %d: %s\n" :
196                                             "", lineno, errmsg);
197                                         quit(2);
198                                 }
199                                 clearerr(stdin);
200                                 modified = 0;
201                                 status = EMOD;
202                                 continue;
203                         } else
204                                 quit(0);
205                 } else if (ibuf[n - 1] != '\n') {
206                         /* discard line */
207                         sprintf(errmsg, "unexpected end-of-file");
208                         clearerr(stdin);
209                         status = ERR;
210                         continue;
211                 }
212                 isglobal = 0;
213                 if ((status = extract_addr_range()) >= 0 &&
214                     (status = exec_command()) >= 0)
215                         if (!status ||
216                             (status = display_lines(current_addr, current_addr,
217                                 status)) >= 0)
218                                 continue;
219                 switch (status) {
220                 case EOF:
221                         quit(0);
222                 case EMOD:
223                         modified = 0;
224                         fputs("?\n", stderr);           /* give warning */
225                         sprintf(errmsg, "warning: file modified");
226                         if (!isatty(0)) {
227                                 fprintf(stderr, garrulous ?
228                                     "script, line %d: %s\n" :
229                                     "", lineno, errmsg);
230                                 quit(2);
231                         }
232                         break;
233                 case FATAL:
234                         if (!isatty(0))
235                                 fprintf(stderr, garrulous ?
236                                     "script, line %d: %s\n" : "",
237                                     lineno, errmsg);
238                         else
239                                 fprintf(stderr, garrulous ? "%s\n" : "",
240                                     errmsg);
241                         quit(3);
242                 default:
243                         fputs("?\n", stderr);
244                         if (!isatty(0)) {
245                                 fprintf(stderr, garrulous ?
246                                     "script, line %d: %s\n" : "",
247                                     lineno, errmsg);
248                                 quit(2);
249                         }
250                         break;
251                 }
252         }
253         /*NOTREACHED*/
254 }
255
256 long first_addr, second_addr, addr_cnt;
257
258 /* extract_addr_range: get line addresses from the command buffer until an
259    illegal address is seen; return status */
260 int
261 extract_addr_range(void)
262 {
263         long addr;
264
265         addr_cnt = 0;
266         first_addr = second_addr = current_addr;
267         while ((addr = next_addr()) >= 0) {
268                 addr_cnt++;
269                 first_addr = second_addr;
270                 second_addr = addr;
271                 if (*ibufp != ',' && *ibufp != ';')
272                         break;
273                 else if (*ibufp++ == ';')
274                         current_addr = addr;
275         }
276         if ((addr_cnt = min(addr_cnt, 2)) == 1 || second_addr != addr)
277                 first_addr = second_addr;
278         return (addr == ERR) ? ERR : 0;
279 }
280
281
282 #define SKIP_BLANKS() while (isspace((unsigned char)*ibufp) && *ibufp != '\n') ibufp++
283
284 #define MUST_BE_FIRST() \
285         if (!first) { sprintf(errmsg, "invalid address"); return ERR; }
286
287 /*  next_addr: return the next line address in the command buffer */
288 long
289 next_addr(void)
290 {
291         char *hd;
292         long addr = current_addr;
293         long n;
294         int first = 1;
295         int c;
296
297         SKIP_BLANKS();
298         for (hd = ibufp;; first = 0)
299                 switch (c = *ibufp) {
300                 case '+':
301                 case '\t':
302                 case ' ':
303                 case '-':
304                 case '^':
305                         ibufp++;
306                         SKIP_BLANKS();
307                         if (isdigit((unsigned char)*ibufp)) {
308                                 STRTOL(n, ibufp);
309                                 addr += (c == '-' || c == '^') ? -n : n;
310                         } else if (!isspace((unsigned char)c))
311                                 addr += (c == '-' || c == '^') ? -1 : 1;
312                         break;
313                 case '0': case '1': case '2':
314                 case '3': case '4': case '5':
315                 case '6': case '7': case '8': case '9':
316                         MUST_BE_FIRST();
317                         STRTOL(addr, ibufp);
318                         break;
319                 case '.':
320                 case '$':
321                         MUST_BE_FIRST();
322                         ibufp++;
323                         addr = (c == '.') ? current_addr : addr_last;
324                         break;
325                 case '/':
326                 case '?':
327                         MUST_BE_FIRST();
328                         if ((addr = get_matching_node_addr(
329                             get_compiled_pattern(), c == '/')) < 0)
330                                 return ERR;
331                         else if (c == *ibufp)
332                                 ibufp++;
333                         break;
334                 case '\'':
335                         MUST_BE_FIRST();
336                         ibufp++;
337                         if ((addr = get_marked_node_addr(*ibufp++)) < 0)
338                                 return ERR;
339                         break;
340                 case '%':
341                 case ',':
342                 case ';':
343                         if (first) {
344                                 ibufp++;
345                                 addr_cnt++;
346                                 second_addr = (c == ';') ? current_addr : 1;
347                                 addr = addr_last;
348                                 break;
349                         }
350                         /* FALL THROUGH */
351                 default:
352                         if (ibufp == hd)
353                                 return EOF;
354                         else if (addr < 0 || addr_last < addr) {
355                                 sprintf(errmsg, "invalid address");
356                                 return ERR;
357                         } else
358                                 return addr;
359                 }
360         /* NOTREACHED */
361 }
362
363
364 #ifdef BACKWARDS
365 /* GET_THIRD_ADDR: get a legal address from the command buffer */
366 #define GET_THIRD_ADDR(addr) \
367 { \
368         long ol1, ol2; \
369 \
370         ol1 = first_addr, ol2 = second_addr; \
371         if (extract_addr_range() < 0) \
372                 return ERR; \
373         else if (addr_cnt == 0) { \
374                 sprintf(errmsg, "destination expected"); \
375                 return ERR; \
376         } else if (second_addr < 0 || addr_last < second_addr) { \
377                 sprintf(errmsg, "invalid address"); \
378                 return ERR; \
379         } \
380         addr = second_addr; \
381         first_addr = ol1, second_addr = ol2; \
382 }
383 #else   /* BACKWARDS */
384 /* GET_THIRD_ADDR: get a legal address from the command buffer */
385 #define GET_THIRD_ADDR(addr) \
386 { \
387         long ol1, ol2; \
388 \
389         ol1 = first_addr, ol2 = second_addr; \
390         if (extract_addr_range() < 0) \
391                 return ERR; \
392         if (second_addr < 0 || addr_last < second_addr) { \
393                 sprintf(errmsg, "invalid address"); \
394                 return ERR; \
395         } \
396         addr = second_addr; \
397         first_addr = ol1, second_addr = ol2; \
398 }
399 #endif
400
401
402 /* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
403 #define GET_COMMAND_SUFFIX() { \
404         int done = 0; \
405         do { \
406                 switch(*ibufp) { \
407                 case 'p': \
408                         gflag |= GPR, ibufp++; \
409                         break; \
410                 case 'l': \
411                         gflag |= GLS, ibufp++; \
412                         break; \
413                 case 'n': \
414                         gflag |= GNP, ibufp++; \
415                         break; \
416                 default: \
417                         done++; \
418                 } \
419         } while (!done); \
420         if (*ibufp++ != '\n') { \
421                 sprintf(errmsg, "invalid command suffix"); \
422                 return ERR; \
423         } \
424 }
425
426
427 /* sflags */
428 #define SGG 001         /* complement previous global substitute suffix */
429 #define SGP 002         /* complement previous print suffix */
430 #define SGR 004         /* use last regex instead of last pat */
431 #define SGF 010         /* repeat last substitution */
432
433 int patlock = 0;        /* if set, pattern not freed by get_compiled_pattern() */
434
435 long rows = 22;         /* scroll length: ws_row - 2 */
436
437 /* exec_command: execute the next command in command buffer; return print
438    request, if any */
439 int
440 exec_command(void)
441 {
442         extern long u_current_addr;
443         extern long u_addr_last;
444
445         static pattern_t *pat = NULL;
446         static int sgflag = 0;
447         static long sgnum = 0;
448
449         pattern_t *tpat;
450         char *fnp;
451         int gflag = 0;
452         int sflags = 0;
453         long addr = 0;
454         int n = 0;
455         int c;
456
457         SKIP_BLANKS();
458         switch(c = *ibufp++) {
459         case 'a':
460                 GET_COMMAND_SUFFIX();
461                 if (!isglobal) clear_undo_stack();
462                 if (append_lines(second_addr) < 0)
463                         return ERR;
464                 break;
465         case 'c':
466                 if (check_addr_range(current_addr, current_addr) < 0)
467                         return ERR;
468                 GET_COMMAND_SUFFIX();
469                 if (!isglobal) clear_undo_stack();
470                 if (delete_lines(first_addr, second_addr) < 0 ||
471                     append_lines(current_addr) < 0)
472                         return ERR;
473                 break;
474         case 'd':
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                         return ERR;
481                 else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
482                         current_addr = addr;
483                 break;
484         case 'e':
485                 if (modified && !scripted)
486                         return EMOD;
487                 /* fall through */
488         case 'E':
489                 if (addr_cnt > 0) {
490                         sprintf(errmsg, "unexpected address");
491                         return ERR;
492                 } else if (!isspace((unsigned char)*ibufp)) {
493                         sprintf(errmsg, "unexpected command suffix");
494                         return ERR;
495                 } else if ((fnp = get_filename()) == NULL)
496                         return ERR;
497                 GET_COMMAND_SUFFIX();
498                 if (delete_lines(1, addr_last) < 0)
499                         return ERR;
500                 clear_undo_stack();
501                 if (close_sbuf() < 0)
502                         return ERR;
503                 else if (open_sbuf() < 0)
504                         return FATAL;
505                 if (*fnp && *fnp != '!') strcpy(old_filename, fnp);
506 #ifdef BACKWARDS
507                 if (*fnp == '\0' && *old_filename == '\0') {
508                         sprintf(errmsg, "no current filename");
509                         return ERR;
510                 }
511 #endif
512                 if (read_file(*fnp ? fnp : old_filename, 0) < 0)
513                         return ERR;
514                 clear_undo_stack();
515                 modified = 0;
516                 u_current_addr = u_addr_last = -1;
517                 break;
518         case 'f':
519                 if (addr_cnt > 0) {
520                         sprintf(errmsg, "unexpected address");
521                         return ERR;
522                 } else if (!isspace((unsigned char)*ibufp)) {
523                         sprintf(errmsg, "unexpected command suffix");
524                         return ERR;
525                 } else if ((fnp = get_filename()) == NULL)
526                         return ERR;
527                 else if (*fnp == '!') {
528                         sprintf(errmsg, "invalid redirection");
529                         return ERR;
530                 }
531                 GET_COMMAND_SUFFIX();
532                 if (*fnp) strcpy(old_filename, fnp);
533                 printf("%s\n", strip_escapes(old_filename));
534                 break;
535         case 'g':
536         case 'v':
537         case 'G':
538         case 'V':
539                 if (isglobal) {
540                         sprintf(errmsg, "cannot nest global commands");
541                         return ERR;
542                 } else if (check_addr_range(1, addr_last) < 0)
543                         return ERR;
544                 else if (build_active_list(c == 'g' || c == 'G') < 0)
545                         return ERR;
546                 else if ((n = (c == 'G' || c == 'V')))
547                         GET_COMMAND_SUFFIX();
548                 isglobal++;
549                 if (exec_global(n, gflag) < 0)
550                         return ERR;
551                 break;
552         case 'h':
553                 if (addr_cnt > 0) {
554                         sprintf(errmsg, "unexpected address");
555                         return ERR;
556                 }
557                 GET_COMMAND_SUFFIX();
558                 if (*errmsg) fprintf(stderr, "%s\n", errmsg);
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 ((garrulous = 1 - garrulous) && *errmsg)
567                         fprintf(stderr, "%s\n", errmsg);
568                 break;
569         case 'i':
570                 if (second_addr == 0) {
571                         sprintf(errmsg, "invalid address");
572                         return ERR;
573                 }
574                 GET_COMMAND_SUFFIX();
575                 if (!isglobal) clear_undo_stack();
576                 if (append_lines(second_addr - 1) < 0)
577                         return ERR;
578                 break;
579         case 'j':
580                 if (check_addr_range(current_addr, current_addr + 1) < 0)
581                         return ERR;
582                 GET_COMMAND_SUFFIX();
583                 if (!isglobal) clear_undo_stack();
584                 if (first_addr != second_addr &&
585                     join_lines(first_addr, second_addr) < 0)
586                         return ERR;
587                 break;
588         case 'k':
589                 c = *ibufp++;
590                 if (second_addr == 0) {
591                         sprintf(errmsg, "invalid address");
592                         return ERR;
593                 }
594                 GET_COMMAND_SUFFIX();
595                 if (mark_line_node(get_addressed_line_node(second_addr), c) < 0)
596                         return ERR;
597                 break;
598         case 'l':
599                 if (check_addr_range(current_addr, current_addr) < 0)
600                         return ERR;
601                 GET_COMMAND_SUFFIX();
602                 if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
603                         return ERR;
604                 gflag = 0;
605                 break;
606         case 'm':
607                 if (check_addr_range(current_addr, current_addr) < 0)
608                         return ERR;
609                 GET_THIRD_ADDR(addr);
610                 if (first_addr <= addr && addr < second_addr) {
611                         sprintf(errmsg, "invalid destination");
612                         return ERR;
613                 }
614                 GET_COMMAND_SUFFIX();
615                 if (!isglobal) clear_undo_stack();
616                 if (move_lines(addr) < 0)
617                         return ERR;
618                 break;
619         case 'n':
620                 if (check_addr_range(current_addr, current_addr) < 0)
621                         return ERR;
622                 GET_COMMAND_SUFFIX();
623                 if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
624                         return ERR;
625                 gflag = 0;
626                 break;
627         case 'p':
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 | GPR) < 0)
632                         return ERR;
633                 gflag = 0;
634                 break;
635         case 'P':
636                 if (addr_cnt > 0) {
637                         sprintf(errmsg, "unexpected address");
638                         return ERR;
639                 }
640                 GET_COMMAND_SUFFIX();
641                 prompt = prompt ? NULL : optarg ? optarg : dps;
642                 break;
643         case 'q':
644         case 'Q':
645                 if (addr_cnt > 0) {
646                         sprintf(errmsg, "unexpected address");
647                         return ERR;
648                 }
649                 GET_COMMAND_SUFFIX();
650                 gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
651                 break;
652         case 'r':
653                 if (!isspace((unsigned char)*ibufp)) {
654                         sprintf(errmsg, "unexpected command suffix");
655                         return ERR;
656                 } else if (addr_cnt == 0)
657                         second_addr = addr_last;
658                 if ((fnp = get_filename()) == NULL)
659                         return ERR;
660                 GET_COMMAND_SUFFIX();
661                 if (!isglobal) clear_undo_stack();
662                 if (*old_filename == '\0' && *fnp != '!')
663                         strcpy(old_filename, fnp);
664 #ifdef BACKWARDS
665                 if (*fnp == '\0' && *old_filename == '\0') {
666                         sprintf(errmsg, "no current filename");
667                         return ERR;
668                 }
669 #endif
670                 if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
671                         return ERR;
672                 else if (addr && addr != addr_last)
673                         modified = 1;
674                 break;
675         case 's':
676                 do {
677                         switch(*ibufp) {
678                         case '\n':
679                                 sflags |=SGF;
680                                 break;
681                         case 'g':
682                                 sflags |= SGG;
683                                 ibufp++;
684                                 break;
685                         case 'p':
686                                 sflags |= SGP;
687                                 ibufp++;
688                                 break;
689                         case 'r':
690                                 sflags |= SGR;
691                                 ibufp++;
692                                 break;
693                         case '0': case '1': case '2': case '3': case '4':
694                         case '5': case '6': case '7': case '8': case '9':
695                                 STRTOL(sgnum, ibufp);
696                                 sflags |= SGF;
697                                 sgflag &= ~GSG;         /* override GSG */
698                                 break;
699                         default:
700                                 if (sflags) {
701                                         sprintf(errmsg, "invalid command suffix");
702                                         return ERR;
703                                 }
704                         }
705                 } while (sflags && *ibufp != '\n');
706                 if (sflags && !pat) {
707                         sprintf(errmsg, "no previous substitution");
708                         return ERR;
709                 } else if (sflags & SGG)
710                         sgnum = 0;              /* override numeric arg */
711                 if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
712                         sprintf(errmsg, "invalid pattern delimiter");
713                         return ERR;
714                 }
715                 tpat = pat;
716                 SPL1();
717                 if ((!sflags || (sflags & SGR)) &&
718                     (tpat = get_compiled_pattern()) == NULL) {
719                         SPL0();
720                         return ERR;
721                 } else if (tpat != pat) {
722                         if (pat) {
723                                 regfree(pat);
724                                 free(pat);
725                         }
726                         pat = tpat;
727                         patlock = 1;            /* reserve pattern */
728                 }
729                 SPL0();
730                 if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
731                         return ERR;
732                 else if (isglobal)
733                         sgflag |= GLB;
734                 else
735                         sgflag &= ~GLB;
736                 if (sflags & SGG)
737                         sgflag ^= GSG;
738                 if (sflags & SGP)
739                         sgflag ^= GPR, sgflag &= ~(GLS | GNP);
740                 do {
741                         switch(*ibufp) {
742                         case 'p':
743                                 sgflag |= GPR, ibufp++;
744                                 break;
745                         case 'l':
746                                 sgflag |= GLS, ibufp++;
747                                 break;
748                         case 'n':
749                                 sgflag |= GNP, ibufp++;
750                                 break;
751                         default:
752                                 n++;
753                         }
754                 } while (!n);
755                 if (check_addr_range(current_addr, current_addr) < 0)
756                         return ERR;
757                 GET_COMMAND_SUFFIX();
758                 if (!isglobal) clear_undo_stack();
759                 if (search_and_replace(pat, sgflag, sgnum) < 0)
760                         return ERR;
761                 break;
762         case 't':
763                 if (check_addr_range(current_addr, current_addr) < 0)
764                         return ERR;
765                 GET_THIRD_ADDR(addr);
766                 GET_COMMAND_SUFFIX();
767                 if (!isglobal) clear_undo_stack();
768                 if (copy_lines(addr) < 0)
769                         return ERR;
770                 break;
771         case 'u':
772                 if (addr_cnt > 0) {
773                         sprintf(errmsg, "unexpected address");
774                         return ERR;
775                 }
776                 GET_COMMAND_SUFFIX();
777                 if (pop_undo_stack() < 0)
778                         return ERR;
779                 break;
780         case 'w':
781         case 'W':
782                 if ((n = *ibufp) == 'q' || n == 'Q') {
783                         gflag = EOF;
784                         ibufp++;
785                 }
786                 if (!isspace((unsigned char)*ibufp)) {
787                         sprintf(errmsg, "unexpected command suffix");
788                         return ERR;
789                 } else if ((fnp = get_filename()) == NULL)
790                         return ERR;
791                 if (addr_cnt == 0 && !addr_last)
792                         first_addr = second_addr = 0;
793                 else if (check_addr_range(1, addr_last) < 0)
794                         return ERR;
795                 GET_COMMAND_SUFFIX();
796                 if (*old_filename == '\0' && *fnp != '!')
797                         strcpy(old_filename, fnp);
798 #ifdef BACKWARDS
799                 if (*fnp == '\0' && *old_filename == '\0') {
800                         sprintf(errmsg, "no current filename");
801                         return ERR;
802                 }
803 #endif
804                 if ((addr = write_file(*fnp ? fnp : old_filename,
805                     (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
806                         return ERR;
807                 else if (addr == addr_last)
808                         modified = 0;
809                 else if (modified && !scripted && n == 'q')
810                         gflag = EMOD;
811                 break;
812         case 'x':
813                 if (addr_cnt > 0) {
814                         sprintf(errmsg, "unexpected address");
815                         return ERR;
816                 }
817                 GET_COMMAND_SUFFIX();
818 #ifdef DES
819                 des = get_keyword();
820 #else
821                 sprintf(errmsg, "crypt unavailable");
822                 return ERR;
823 #endif
824                 break;
825         case 'z':
826 #ifdef BACKWARDS
827                 if (check_addr_range(first_addr = 1, current_addr + 1) < 0)
828 #else
829                 if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0)
830 #endif
831                         return ERR;
832                 else if ('0' < *ibufp && *ibufp <= '9')
833                         STRTOL(rows, ibufp);
834                 GET_COMMAND_SUFFIX();
835                 if (display_lines(second_addr, min(addr_last,
836                     second_addr + rows), gflag) < 0)
837                         return ERR;
838                 gflag = 0;
839                 break;
840         case '=':
841                 GET_COMMAND_SUFFIX();
842                 printf("%ld\n", addr_cnt ? second_addr : addr_last);
843                 break;
844         case '!':
845                 if (addr_cnt > 0) {
846                         sprintf(errmsg, "unexpected address");
847                         return ERR;
848                 } else if ((sflags = get_shell_command()) < 0)
849                         return ERR;
850                 GET_COMMAND_SUFFIX();
851                 if (sflags) printf("%s\n", shcmd + 1);
852                 system(shcmd + 1);
853                 if (!scripted) printf("!\n");
854                 break;
855         case '\n':
856 #ifdef BACKWARDS
857                 if (check_addr_range(first_addr = 1, current_addr + 1) < 0
858 #else
859                 if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0
860 #endif
861                  || display_lines(second_addr, second_addr, 0) < 0)
862                         return ERR;
863                 break;
864         default:
865                 sprintf(errmsg, "unknown command");
866                 return ERR;
867         }
868         return gflag;
869 }
870
871
872 /* check_addr_range: return status of address range check */
873 int
874 check_addr_range(long n, long m)
875 {
876         if (addr_cnt == 0) {
877                 first_addr = n;
878                 second_addr = m;
879         }
880         if (first_addr > second_addr || 1 > first_addr ||
881             second_addr > addr_last) {
882                 sprintf(errmsg, "invalid address");
883                 return ERR;
884         }
885         return 0;
886 }
887
888
889 /* get_matching_node_addr: return the address of the next line matching a
890    pattern in a given direction.  wrap around begin/end of editor buffer if
891    necessary */
892 long
893 get_matching_node_addr(pattern_t *pat, int dir)
894 {
895         char *s;
896         long n = current_addr;
897         line_t *lp;
898
899         if (!pat) return ERR;
900         do {
901                if ((n = dir ? INC_MOD(n, addr_last) : DEC_MOD(n, addr_last))) {
902                         lp = get_addressed_line_node(n);
903                         if ((s = get_sbuf_line(lp)) == NULL)
904                                 return ERR;
905                         if (isbinary)
906                                 NUL_TO_NEWLINE(s, lp->len);
907                         if (!regexec(pat, s, 0, NULL, 0))
908                                 return n;
909                }
910         } while (n != current_addr);
911         sprintf(errmsg, "no match");
912         return  ERR;
913 }
914
915
916 /* get_filename: return pointer to copy of filename in the command buffer */
917 char *
918 get_filename(void)
919 {
920         static char *file = NULL;
921         static int filesz = 0;
922
923         int n;
924
925         if (*ibufp != '\n') {
926                 SKIP_BLANKS();
927                 if (*ibufp == '\n') {
928                         sprintf(errmsg, "invalid filename");
929                         return NULL;
930                 } else if ((ibufp = get_extended_line(&n, 1)) == NULL)
931                         return NULL;
932                 else if (*ibufp == '!') {
933                         ibufp++;
934                         if ((n = get_shell_command()) < 0)
935                                 return NULL;
936                         if (n)
937                                 printf("%s\n", shcmd + 1);
938                         return shcmd;
939                 } else if (n > PATH_MAX - 1) {
940                         sprintf(errmsg, "filename too long");
941                         return  NULL;
942                 }
943         }
944 #ifndef BACKWARDS
945         else if (*old_filename == '\0') {
946                 sprintf(errmsg, "no current filename");
947                 return  NULL;
948         }
949 #endif
950         REALLOC(file, filesz, PATH_MAX, NULL);
951         for (n = 0; *ibufp != '\n';)
952                 file[n++] = *ibufp++;
953         file[n] = '\0';
954         return is_legal_filename(file) ? file : NULL;
955 }
956
957
958 /* get_shell_command: read a shell command from stdin; return substitution
959    status */
960 int
961 get_shell_command(void)
962 {
963         static char *buf = NULL;
964         static int n = 0;
965
966         char *s;                        /* substitution char pointer */
967         int i = 0;
968         int j = 0;
969
970         if (red) {
971                 sprintf(errmsg, "shell access restricted");
972                 return ERR;
973         } else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
974                 return ERR;
975         REALLOC(buf, n, j + 1, ERR);
976         buf[i++] = '!';                 /* prefix command w/ bang */
977         while (*ibufp != '\n')
978                 switch (*ibufp) {
979                 default:
980                         REALLOC(buf, n, i + 2, ERR);
981                         buf[i++] = *ibufp;
982                         if (*ibufp++ == '\\')
983                                 buf[i++] = *ibufp++;
984                         break;
985                 case '!':
986                         if (s != ibufp) {
987                                 REALLOC(buf, n, i + 1, ERR);
988                                 buf[i++] = *ibufp++;
989                         }
990 #ifdef BACKWARDS
991                         else if (shcmd == NULL || *(shcmd + 1) == '\0')
992 #else
993                         else if (shcmd == NULL)
994 #endif
995                         {
996                                 sprintf(errmsg, "no previous command");
997                                 return ERR;
998                         } else {
999                                 REALLOC(buf, n, i + shcmdi, ERR);
1000                                 for (s = shcmd + 1; s < shcmd + shcmdi;)
1001                                         buf[i++] = *s++;
1002                                 s = ibufp++;
1003                         }
1004                         break;
1005                 case '%':
1006                         if (*old_filename  == '\0') {
1007                                 sprintf(errmsg, "no current filename");
1008                                 return ERR;
1009                         }
1010                         j = strlen(s = strip_escapes(old_filename));
1011                         REALLOC(buf, n, i + j, ERR);
1012                         while (j--)
1013                                 buf[i++] = *s++;
1014                         s = ibufp++;
1015                         break;
1016                 }
1017         REALLOC(shcmd, shcmdsz, i + 1, ERR);
1018         memcpy(shcmd, buf, i);
1019         shcmd[shcmdi = i] = '\0';
1020         return *s == '!' || *s == '%';
1021 }
1022
1023
1024 /* append_lines: insert text from stdin to after line n; stop when either a
1025    single period is read or EOF; return status */
1026 int
1027 append_lines(long n)
1028 {
1029         int l;
1030         char *lp = ibuf;
1031         char *eot;
1032         undo_t *up = NULL;
1033
1034         for (current_addr = n;;) {
1035                 if (!isglobal) {
1036                         if ((l = get_tty_line()) < 0)
1037                                 return ERR;
1038                         else if (l == 0 || ibuf[l - 1] != '\n') {
1039                                 clearerr(stdin);
1040                                 return  l ? EOF : 0;
1041                         }
1042                         lp = ibuf;
1043                 } else if (*(lp = ibufp) == '\0')
1044                         return 0;
1045                 else {
1046                         while (*ibufp++ != '\n')
1047                                 ;
1048                         l = ibufp - lp;
1049                 }
1050                 if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1051                         return 0;
1052                 }
1053                 eot = lp + l;
1054                 SPL1();
1055                 do {
1056                         if ((lp = put_sbuf_line(lp)) == NULL) {
1057                                 SPL0();
1058                                 return ERR;
1059                         } else if (up)
1060                                 up->t = get_addressed_line_node(current_addr);
1061                         else if ((up = push_undo_stack(UADD, current_addr,
1062                             current_addr)) == NULL) {
1063                                 SPL0();
1064                                 return ERR;
1065                         }
1066                 } while (lp != eot);
1067                 modified = 1;
1068                 SPL0();
1069         }
1070         /* NOTREACHED */
1071 }
1072
1073
1074 /* join_lines: replace a range of lines with the joined text of those lines */
1075 int
1076 join_lines(long from, long to)
1077 {
1078         static char *buf = NULL;
1079         static int n;
1080
1081         char *s;
1082         int size = 0;
1083         line_t *bp, *ep;
1084
1085         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1086         bp = get_addressed_line_node(from);
1087         for (; bp != ep; bp = bp->q_forw) {
1088                 if ((s = get_sbuf_line(bp)) == NULL)
1089                         return ERR;
1090                 REALLOC(buf, n, size + bp->len, ERR);
1091                 memcpy(buf + size, s, bp->len);
1092                 size += bp->len;
1093         }
1094         REALLOC(buf, n, size + 2, ERR);
1095         memcpy(buf + size, "\n", 2);
1096         if (delete_lines(from, to) < 0)
1097                 return ERR;
1098         current_addr = from - 1;
1099         SPL1();
1100         if (put_sbuf_line(buf) == NULL ||
1101             push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1102                 SPL0();
1103                 return ERR;
1104         }
1105         modified = 1;
1106         SPL0();
1107         return 0;
1108 }
1109
1110
1111 /* move_lines: move a range of lines */
1112 int
1113 move_lines(long addr)
1114 {
1115         line_t *b1, *a1, *b2, *a2;
1116         long n = INC_MOD(second_addr, addr_last);
1117         long p = first_addr - 1;
1118         int done = (addr == first_addr - 1 || addr == second_addr);
1119
1120         SPL1();
1121         if (done) {
1122                 a2 = get_addressed_line_node(n);
1123                 b2 = get_addressed_line_node(p);
1124                 current_addr = second_addr;
1125         } else if (push_undo_stack(UMOV, p, n) == NULL ||
1126             push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1127                 SPL0();
1128                 return ERR;
1129         } else {
1130                 a1 = get_addressed_line_node(n);
1131                 if (addr < first_addr) {
1132                         b1 = get_addressed_line_node(p);
1133                         b2 = get_addressed_line_node(addr);
1134                                         /* this get_addressed_line_node last! */
1135                 } else {
1136                         b2 = get_addressed_line_node(addr);
1137                         b1 = get_addressed_line_node(p);
1138                                         /* this get_addressed_line_node last! */
1139                 }
1140                 a2 = b2->q_forw;
1141                 REQUE(b2, b1->q_forw);
1142                 REQUE(a1->q_back, a2);
1143                 REQUE(b1, a1);
1144                 current_addr = addr + ((addr < first_addr) ?
1145                     second_addr - first_addr + 1 : 0);
1146         }
1147         if (isglobal)
1148                 unset_active_nodes(b2->q_forw, a2);
1149         modified = 1;
1150         SPL0();
1151         return 0;
1152 }
1153
1154
1155 /* copy_lines: copy a range of lines; return status */
1156 int
1157 copy_lines(long addr)
1158 {
1159         line_t *lp, *np = get_addressed_line_node(first_addr);
1160         undo_t *up = NULL;
1161         long n = second_addr - first_addr + 1;
1162         long m = 0;
1163
1164         current_addr = addr;
1165         if (first_addr <= addr && addr < second_addr) {
1166                 n =  addr - first_addr + 1;
1167                 m = second_addr - addr;
1168         }
1169         for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1170                 for (; n-- > 0; np = np->q_forw) {
1171                         SPL1();
1172                         if ((lp = dup_line_node(np)) == NULL) {
1173                                 SPL0();
1174                                 return ERR;
1175                         }
1176                         add_line_node(lp);
1177                         if (up)
1178                                 up->t = lp;
1179                         else if ((up = push_undo_stack(UADD, current_addr,
1180                             current_addr)) == NULL) {
1181                                 SPL0();
1182                                 return ERR;
1183                         }
1184                         modified = 1;
1185                         SPL0();
1186                 }
1187         return 0;
1188 }
1189
1190
1191 /* delete_lines: delete a range of lines */
1192 int
1193 delete_lines(long from, long to)
1194 {
1195         line_t *n, *p;
1196
1197         SPL1();
1198         if (push_undo_stack(UDEL, from, to) == NULL) {
1199                 SPL0();
1200                 return ERR;
1201         }
1202         n = get_addressed_line_node(INC_MOD(to, addr_last));
1203         p = get_addressed_line_node(from - 1);
1204                                         /* this get_addressed_line_node last! */
1205         if (isglobal)
1206                 unset_active_nodes(p->q_forw, n);
1207         REQUE(p, n);
1208         addr_last -= to - from + 1;
1209         current_addr = from - 1;
1210         modified = 1;
1211         SPL0();
1212         return 0;
1213 }
1214
1215
1216 /* display_lines: print a range of lines to stdout */
1217 int
1218 display_lines(long from, long to, int gflag)
1219 {
1220         line_t *bp;
1221         line_t *ep;
1222         char *s;
1223
1224         if (!from) {
1225                 sprintf(errmsg, "invalid address");
1226                 return ERR;
1227         }
1228         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1229         bp = get_addressed_line_node(from);
1230         for (; bp != ep; bp = bp->q_forw) {
1231                 if ((s = get_sbuf_line(bp)) == NULL)
1232                         return ERR;
1233                 if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1234                         return ERR;
1235         }
1236         return 0;
1237 }
1238
1239
1240 #define MAXMARK 26                      /* max number of marks */
1241
1242 line_t  *mark[MAXMARK];                 /* line markers */
1243 int markno;                             /* line marker count */
1244
1245 /* mark_line_node: set a line node mark */
1246 int
1247 mark_line_node(line_t *lp, int n)
1248 {
1249         if (!islower((unsigned char)n)) {
1250                 sprintf(errmsg, "invalid mark character");
1251                 return ERR;
1252         } else if (mark[n - 'a'] == NULL)
1253                 markno++;
1254         mark[n - 'a'] = lp;
1255         return 0;
1256 }
1257
1258
1259 /* get_marked_node_addr: return address of a marked line */
1260 long
1261 get_marked_node_addr(int n)
1262 {
1263         if (!islower((unsigned char)n)) {
1264                 sprintf(errmsg, "invalid mark character");
1265                 return ERR;
1266         }
1267         return get_line_node_addr(mark[n - 'a']);
1268 }
1269
1270
1271 /* unmark_line_node: clear line node mark */
1272 void
1273 unmark_line_node(line_t *lp)
1274 {
1275         int i;
1276
1277         for (i = 0; markno && i < MAXMARK; i++)
1278                 if (mark[i] == lp) {
1279                         mark[i] = NULL;
1280                         markno--;
1281                 }
1282 }
1283
1284
1285 /* dup_line_node: return a pointer to a copy of a line node */
1286 line_t *
1287 dup_line_node(line_t *lp)
1288 {
1289         line_t *np;
1290
1291         if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1292                 fprintf(stderr, "%s\n", strerror(errno));
1293                 sprintf(errmsg, "out of memory");
1294                 return NULL;
1295         }
1296         np->seek = lp->seek;
1297         np->len = lp->len;
1298         return np;
1299 }
1300
1301
1302 /* has_trailing_escape:  return the parity of escapes preceding a character
1303    in a string */
1304 int
1305 has_trailing_escape(char *s, char *t)
1306 {
1307     return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1308 }
1309
1310
1311 /* strip_escapes: return copy of escaped string of at most length PATH_MAX */
1312 char *
1313 strip_escapes(const char *s)
1314 {
1315         static char *file = NULL;
1316         static int filesz = 0;
1317
1318         int i = 0;
1319
1320         REALLOC(file, filesz, PATH_MAX, NULL);
1321         while (i < filesz - 1   /* Worry about a possible trailing escape */
1322                && (file[i++] = (*s == '\\') ? *++s : *s))
1323                 s++;
1324         return file;
1325 }
1326
1327
1328 void
1329 signal_hup(int signo)
1330 {
1331         if (mutex)
1332                 sigflags |= (1 << (signo - 1));
1333         else
1334                 handle_hup(signo);
1335 }
1336
1337
1338 void
1339 signal_int(int signo)
1340 {
1341         if (mutex)
1342                 sigflags |= (1 << (signo - 1));
1343         else
1344                 handle_int(signo);
1345 }
1346
1347
1348 void
1349 handle_hup(int signo)
1350 {
1351         char *hup = NULL;               /* hup filename */
1352         char *s;
1353         int n;
1354
1355         if (!sigactive)
1356                 quit(1);
1357         sigflags &= ~(1 << (signo - 1));
1358         if (addr_last && write_file("ed.hup", "w", 1, addr_last) < 0 &&
1359             (s = getenv("HOME")) != NULL &&
1360             (n = strlen(s)) + 8 <= PATH_MAX &&  /* "ed.hup" + '/' */
1361             (hup = (char *) malloc(n + 10)) != NULL) {
1362                 strcpy(hup, s);
1363                 if (hup[n - 1] != '/')
1364                         hup[n] = '/', hup[n+1] = '\0';
1365                 strcat(hup, "ed.hup");
1366                 write_file(hup, "w", 1, addr_last);
1367         }
1368         quit(2);
1369 }
1370
1371
1372 void
1373 handle_int(int signo)
1374 {
1375         if (!sigactive)
1376                 quit(1);
1377         sigflags &= ~(1 << (signo - 1));
1378 #ifdef _POSIX_SOURCE
1379         siglongjmp(env, -1);
1380 #else
1381         longjmp(env, -1);
1382 #endif
1383 }
1384
1385
1386 int cols = 72;                          /* wrap column */
1387
1388 void
1389 handle_winch(int signo)
1390 {
1391         int save_errno = errno;
1392
1393         struct winsize ws;              /* window size structure */
1394
1395         sigflags &= ~(1 << (signo - 1));
1396         if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1397                 if (ws.ws_row > 2) rows = ws.ws_row - 2;
1398                 if (ws.ws_col > 8) cols = ws.ws_col - 8;
1399         }
1400         errno = save_errno;
1401 }
1402
1403
1404 /* is_legal_filename: return a legal filename */
1405 int
1406 is_legal_filename(char *s)
1407 {
1408         if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1409                 sprintf(errmsg, "shell access restricted");
1410                 return 0;
1411         }
1412         return 1;
1413 }