Commit | Line | Data |
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f3270895 MH |
1 | /* Copyright (c) 1979 Regents of the University of California */ |
2 | #include "ex.h" | |
3 | #include "ex_temp.h" | |
4 | #include "ex_tty.h" | |
5 | #include "local/uparm.h" | |
6 | ||
7 | #undef BUFSIZ | |
8 | #undef EOF | |
9 | #undef NULL | |
10 | ||
11 | #include <stdio.h> | |
12 | #include <sys/dir.h> | |
13 | ||
14 | /* | |
15 | * Ex recovery program | |
16 | * exrecover dir name | |
17 | * exrecover -r | |
18 | * | |
19 | * This program searches through the specified directory and then | |
20 | * the directory usrpath(preserve) looking for an instance of the specified | |
21 | * file from a crashed editor or a crashed system. | |
22 | * If this file is found, it is unscrambled and written to | |
23 | * the standard output. | |
24 | * | |
25 | * If this program terminates without a "broken pipe" diagnostic | |
26 | * (i.e. the editor doesn't die right away) then the buffer we are | |
27 | * writing from is removed when we finish. This is potentially a mistake | |
28 | * as there is not enough handshaking to guarantee that the file has actually | |
29 | * been recovered, but should suffice for most cases. | |
30 | */ | |
31 | ||
32 | /* | |
33 | * For lint's sake... | |
34 | */ | |
35 | #ifndef lint | |
36 | #define ignorl(a) a | |
37 | #endif | |
38 | ||
39 | /* | |
40 | * This directory definition also appears (obviously) in expreserve.c. | |
41 | * Change both if you change either. | |
42 | */ | |
43 | char mydir[] = usrpath(preserve); | |
44 | ||
45 | /* | |
46 | * Limit on the number of printed entries | |
47 | * when an, e.g. ``ex -r'' command is given. | |
48 | */ | |
49 | #define NENTRY 50 | |
50 | ||
51 | char *ctime(); | |
52 | char nb[BUFSIZ]; | |
53 | int vercnt; /* Count number of versions of file found */ | |
54 | ||
55 | main(argc, argv) | |
56 | int argc; | |
57 | char *argv[]; | |
58 | { | |
59 | register char *cp; | |
60 | register int b, i; | |
61 | ||
62 | /* | |
63 | * Initialize as though the editor had just started. | |
64 | */ | |
65 | fendcore = (line *) sbrk(0); | |
66 | dot = zero = dol = fendcore; | |
67 | one = zero + 1; | |
68 | endcore = fendcore - 2; | |
69 | iblock = oblock = -1; | |
70 | ||
71 | /* | |
72 | * If given only a -r argument, then list the saved files. | |
73 | */ | |
74 | if (argc == 2 && eq(argv[1], "-r")) { | |
75 | listfiles(mydir); | |
76 | exit(0); | |
77 | } | |
78 | if (argc != 3) | |
79 | error(" Wrong number of arguments to exrecover", 0); | |
80 | ||
81 | CP(file, argv[2]); | |
82 | ||
83 | /* | |
84 | * Search for this file. | |
85 | */ | |
86 | findtmp(argv[1]); | |
87 | ||
88 | /* | |
89 | * Got (one of the versions of) it, write it back to the editor. | |
90 | */ | |
91 | cp = ctime(&H.Time); | |
92 | cp[19] = 0; | |
93 | fprintf(stderr, " [Dated: %s", cp); | |
94 | fprintf(stderr, vercnt > 1 ? ", newest of %d saved]" : "]", vercnt); | |
95 | H.Flines++; | |
96 | ||
97 | /* | |
98 | * Allocate space for the line pointers from the temp file. | |
99 | */ | |
100 | if ((int) sbrk((int) (H.Flines * sizeof (line))) == -1) | |
101 | /* | |
102 | * Good grief. | |
103 | */ | |
104 | error(" Not enough core for lines", 0); | |
105 | #ifdef DEBUG | |
106 | fprintf(stderr, "%d lines\n", H.Flines); | |
107 | #endif | |
108 | ||
109 | /* | |
110 | * Now go get the blocks of seek pointers which are scattered | |
111 | * throughout the temp file, reconstructing the incore | |
112 | * line pointers at point of crash. | |
113 | */ | |
114 | b = 0; | |
115 | while (H.Flines > 0) { | |
116 | ignorl(lseek(tfile, (long) blocks[b] * BUFSIZ, 0)); | |
117 | i = H.Flines < BUFSIZ / sizeof (line) ? | |
118 | H.Flines * sizeof (line) : BUFSIZ; | |
119 | if (read(tfile, (char *) dot, i) != i) { | |
120 | perror(nb); | |
121 | exit(1); | |
122 | } | |
123 | dot += i / sizeof (line); | |
124 | H.Flines -= i / sizeof (line); | |
125 | b++; | |
126 | } | |
127 | dot--; dol = dot; | |
128 | ||
129 | /* | |
130 | * Sigh... due to sandbagging some lines may really not be there. | |
131 | * Find and discard such. This shouldn't happen much. | |
132 | */ | |
133 | scrapbad(); | |
134 | ||
135 | /* | |
136 | * Now if there were any lines in the recovered file | |
137 | * write them to the standard output. | |
138 | */ | |
139 | if (dol > zero) { | |
140 | addr1 = one; addr2 = dol; io = 1; | |
141 | putfile(); | |
142 | } | |
143 | ||
144 | /* | |
145 | * Trash the saved buffer. | |
146 | * Hopefully the system won't crash before the editor | |
147 | * syncs the new recovered buffer; i.e. for an instant here | |
148 | * you may lose if the system crashes because this file | |
149 | * is gone, but the editor hasn't completed reading the recovered | |
150 | * file from the pipe from us to it. | |
151 | * | |
152 | * This doesn't work if we are coming from an non-absolute path | |
153 | * name since we may have chdir'ed but what the hay, noone really | |
154 | * ever edits with temporaries in "." anyways. | |
155 | */ | |
156 | if (nb[0] == '/') | |
157 | ignore(unlink(nb)); | |
158 | ||
159 | /* | |
160 | * Adieu. | |
161 | */ | |
162 | exit(0); | |
163 | } | |
164 | ||
165 | /* | |
166 | * Print an error message (notably not in error | |
167 | * message file). If terminal is in RAW mode, then | |
168 | * we should be writing output for "vi", so don't print | |
169 | * a newline which would screw up the screen. | |
170 | */ | |
171 | /*VARARGS2*/ | |
172 | error(str, inf) | |
173 | char *str; | |
174 | int inf; | |
175 | { | |
176 | ||
177 | fprintf(stderr, str, inf); | |
178 | gtty(2, &tty); | |
179 | if ((tty.sg_flags & RAW) == 0) | |
180 | fprintf(stderr, "\n"); | |
181 | exit(1); | |
182 | } | |
183 | ||
184 | /* | |
185 | * Here we save the information about files, when | |
186 | * you ask us what files we have saved for you. | |
187 | * We buffer file name, number of lines, and the time | |
188 | * at which the file was saved. | |
189 | */ | |
190 | struct svfile { | |
191 | char sf_name[FNSIZE + 1]; | |
192 | int sf_lines; | |
193 | char sf_entry[DIRSIZ + 1]; | |
194 | time_t sf_time; | |
195 | }; | |
196 | ||
197 | listfiles(dirname) | |
198 | char *dirname; | |
199 | { | |
200 | register FILE *dir; | |
201 | struct direct dirent; | |
202 | int ecount, qucmp(); | |
203 | register int f; | |
204 | char *cp; | |
205 | struct svfile *fp, svbuf[NENTRY]; | |
206 | ||
207 | /* | |
208 | * Open usrpath(preserve), and go there to make things quick. | |
209 | */ | |
210 | dir = fopen(dirname, "r"); | |
211 | if (dir == NULL) { | |
212 | perror(dirname); | |
213 | return; | |
214 | } | |
215 | if (chdir(dirname) < 0) { | |
216 | perror(dirname); | |
217 | return; | |
218 | } | |
219 | ||
220 | /* | |
221 | * Look at the candidate files in usrpath(preserve). | |
222 | */ | |
223 | fp = &svbuf[0]; | |
224 | ecount = 0; | |
225 | while (fread((char *) &dirent, sizeof dirent, 1, dir) == 1) { | |
226 | if (dirent.d_ino == 0) | |
227 | continue; | |
228 | if (dirent.d_name[0] != 'E') | |
229 | continue; | |
230 | #ifdef DEBUG | |
231 | fprintf(stderr, "considering %s\n", dirent.d_name); | |
232 | #endif | |
233 | /* | |
234 | * Name begins with E; open it and | |
235 | * make sure the uid in the header is our uid. | |
236 | * If not, then don't bother with this file, it can't | |
237 | * be ours. | |
238 | */ | |
239 | f = open(dirent.d_name, 0); | |
240 | if (f < 0) { | |
241 | #ifdef DEBUG | |
242 | fprintf(stderr, "open failed\n"); | |
243 | #endif | |
244 | continue; | |
245 | } | |
246 | if (read(f, (char *) &H, sizeof H) != sizeof H) { | |
247 | #ifdef DEBUG | |
248 | fprintf(stderr, "culdnt read hedr\n"); | |
249 | #endif | |
250 | ignore(close(f)); | |
251 | continue; | |
252 | } | |
253 | ignore(close(f)); | |
254 | if (getuid() != H.Uid) { | |
255 | #ifdef DEBUG | |
256 | fprintf(stderr, "uid wrong\n"); | |
257 | #endif | |
258 | continue; | |
259 | } | |
260 | ||
261 | /* | |
262 | * Saved the day! | |
263 | */ | |
264 | enter(fp++, dirent.d_name, ecount); | |
265 | ecount++; | |
266 | #ifdef DEBUG | |
267 | fprintf(stderr, "entered file %s\n", dirent.d_name); | |
268 | #endif | |
269 | } | |
270 | ignore(fclose(dir)); | |
271 | ||
272 | /* | |
273 | * If any files were saved, then sort them and print | |
274 | * them out. | |
275 | */ | |
276 | if (ecount == 0) { | |
277 | fprintf(stderr, "No files saved.\n"); | |
278 | return; | |
279 | } | |
280 | qsort(&svbuf[0], ecount, sizeof svbuf[0], qucmp); | |
281 | for (fp = &svbuf[0]; fp < &svbuf[ecount]; fp++) { | |
282 | cp = ctime(&fp->sf_time); | |
283 | cp[10] = 0; | |
284 | fprintf(stderr, "On %s at ", cp); | |
285 | cp[16] = 0; | |
286 | fprintf(stderr, &cp[11]); | |
287 | fprintf(stderr, " saved %d lines of file \"%s\"\n", | |
288 | fp->sf_lines, fp->sf_name); | |
289 | } | |
290 | } | |
291 | ||
292 | /* | |
293 | * Enter a new file into the saved file information. | |
294 | */ | |
295 | enter(fp, fname, count) | |
296 | struct svfile *fp; | |
297 | char *fname; | |
298 | { | |
299 | register char *cp, *cp2; | |
300 | register struct svfile *f, *fl; | |
301 | time_t curtime, itol(); | |
302 | ||
303 | f = 0; | |
304 | if (count >= NENTRY) { | |
305 | /* | |
306 | * My god, a huge number of saved files. | |
307 | * Would you work on a system that crashed this | |
308 | * often? Hope not. So lets trash the oldest | |
309 | * as the most useless. | |
310 | * | |
311 | * (I wonder if this code has ever run?) | |
312 | */ | |
313 | fl = fp - count + NENTRY - 1; | |
314 | curtime = fl->sf_time; | |
315 | for (f = fl; --f > fp-count; ) | |
316 | if (f->sf_time < curtime) | |
317 | curtime = f->sf_time; | |
318 | for (f = fl; --f > fp-count; ) | |
319 | if (f->sf_time == curtime) | |
320 | break; | |
321 | fp = f; | |
322 | } | |
323 | ||
324 | /* | |
325 | * Gotcha. | |
326 | */ | |
327 | fp->sf_time = H.Time; | |
328 | fp->sf_lines = H.Flines; | |
329 | for (cp2 = fp->sf_name, cp = savedfile; *cp;) | |
330 | *cp2++ = *cp++; | |
331 | for (cp2 = fp->sf_entry, cp = fname; *cp && cp-fname < 14;) | |
332 | *cp2++ = *cp++; | |
333 | *cp2++ = 0; | |
334 | } | |
335 | ||
336 | /* | |
337 | * Do the qsort compare to sort the entries first by file name, | |
338 | * then by modify time. | |
339 | */ | |
340 | qucmp(p1, p2) | |
341 | struct svfile *p1, *p2; | |
342 | { | |
343 | register int t; | |
344 | ||
345 | if (t = strcmp(p1->sf_name, p2->sf_name)) | |
346 | return(t); | |
347 | if (p1->sf_time > p2->sf_time) | |
348 | return(-1); | |
349 | return(p1->sf_time < p2->sf_time); | |
350 | } | |
351 | ||
352 | /* | |
353 | * Scratch for search. | |
354 | */ | |
355 | char bestnb[BUFSIZ]; /* Name of the best one */ | |
356 | long besttime; /* Time at which the best file was saved */ | |
357 | int bestfd; /* Keep best file open so it dont vanish */ | |
358 | ||
359 | /* | |
360 | * Look for a file, both in the users directory option value | |
361 | * (i.e. usually /tmp) and in usrpath(preserve). | |
362 | * Want to find the newest so we search on and on. | |
363 | */ | |
364 | findtmp(dir) | |
365 | char *dir; | |
366 | { | |
367 | ||
368 | /* | |
369 | * No name or file so far. | |
370 | */ | |
371 | bestnb[0] = 0; | |
372 | bestfd = -1; | |
373 | ||
374 | /* | |
375 | * Search usrpath(preserve) and, if we can get there, /tmp | |
376 | * (actually the users "directory" option). | |
377 | */ | |
378 | searchdir(dir); | |
379 | if (chdir(mydir) == 0) | |
380 | searchdir(mydir); | |
381 | if (bestfd != -1) { | |
382 | /* | |
383 | * Gotcha. | |
384 | * Put the file (which is already open) in the file | |
385 | * used by the temp file routines, and save its | |
386 | * name for later unlinking. | |
387 | */ | |
388 | tfile = bestfd; | |
389 | CP(nb, bestnb); | |
390 | ignorl(lseek(tfile, 0l, 0)); | |
391 | ||
392 | /* | |
393 | * Gotta be able to read the header or fall through | |
394 | * to lossage. | |
395 | */ | |
396 | if (read(tfile, (char *) &H, sizeof H) == sizeof H) | |
397 | return; | |
398 | } | |
399 | ||
400 | /* | |
401 | * Extreme lossage... | |
402 | */ | |
403 | error(" File not found", 0); | |
404 | } | |
405 | ||
406 | /* | |
407 | * Search for the file in directory dirname. | |
408 | * | |
409 | * Don't chdir here, because the users directory | |
410 | * may be ".", and we would move away before we searched it. | |
411 | * Note that we actually chdir elsewhere (because it is too slow | |
412 | * to look around in usrpath(preserve) without chdir'ing there) so we | |
413 | * can't win, because we don't know the name of '.' and if the path | |
414 | * name of the file we want to unlink is relative, rather than absolute | |
415 | * we won't be able to find it again. | |
416 | */ | |
417 | searchdir(dirname) | |
418 | char *dirname; | |
419 | { | |
420 | struct direct dirent; | |
421 | register FILE *dir; | |
422 | char dbuf[BUFSIZ]; | |
423 | ||
424 | dir = fopen(dirname, "r"); | |
425 | if (dir == NULL) | |
426 | return; | |
427 | setbuf(dir, dbuf); | |
428 | while (fread((char *) &dirent, sizeof dirent, 1, dir) == 1) { | |
429 | if (dirent.d_ino == 0) | |
430 | continue; | |
431 | if (dirent.d_name[0] != 'E' || dirent.d_name[DIRSIZ - 1] != 0) | |
432 | continue; | |
433 | /* | |
434 | * Got a file in the directory starting with E... | |
435 | * Save a consed up name for the file to unlink | |
436 | * later, and check that this is really a file | |
437 | * we are looking for. | |
438 | */ | |
439 | ignore(strcat(strcat(strcpy(nb, dirname), "/"), dirent.d_name)); | |
440 | if (yeah(nb)) { | |
441 | /* | |
442 | * Well, it is the file we are looking for. | |
443 | * Is it more recent than any version we found before? | |
444 | */ | |
445 | if (H.Time > besttime) { | |
446 | /* | |
447 | * A winner. | |
448 | */ | |
449 | ignore(close(bestfd)); | |
450 | bestfd = dup(tfile); | |
451 | besttime = H.Time; | |
452 | CP(bestnb, nb); | |
453 | } | |
454 | /* | |
455 | * Count versions so user can be told there are | |
456 | * ``yet more pages to be turned''. | |
457 | */ | |
458 | vercnt++; | |
459 | } | |
460 | ignore(close(tfile)); | |
461 | } | |
462 | ignore(fclose(dir)); | |
463 | } | |
464 | ||
465 | /* | |
466 | * Given a candidate file to be recovered, see | |
467 | * if its really an editor temporary and of this | |
468 | * user and the file specified. | |
469 | */ | |
470 | yeah(name) | |
471 | char *name; | |
472 | { | |
473 | ||
474 | tfile = open(name, 2); | |
475 | if (tfile < 0) | |
476 | return (0); | |
477 | if (read(tfile, (char *) &H, sizeof H) != sizeof H) { | |
478 | nope: | |
479 | ignore(close(tfile)); | |
480 | return (0); | |
481 | } | |
482 | if (!eq(savedfile, file)) | |
483 | goto nope; | |
484 | if (getuid() != H.Uid) | |
485 | goto nope; | |
486 | /* | |
487 | * This is old and stupid code, which | |
488 | * puts a word LOST in the header block, so that lost lines | |
489 | * can be made to point at it. | |
490 | */ | |
44232d5b | 491 | ignorl(lseek(tfile, (long)(BUFSIZ*HBLKS-8), 0)); |
f3270895 MH |
492 | ignore(write(tfile, "LOST", 5)); |
493 | return (1); | |
494 | } | |
495 | ||
496 | preserve() | |
497 | { | |
498 | ||
499 | } | |
500 | ||
501 | /* | |
502 | * Find the true end of the scratch file, and ``LOSE'' | |
503 | * lines which point into thin air. This lossage occurs | |
504 | * due to the sandbagging of i/o which can cause blocks to | |
505 | * be written in a non-obvious order, different from the order | |
506 | * in which the editor tried to write them. | |
507 | * | |
508 | * Lines which are lost are replaced with the text LOST so | |
509 | * they are easy to find. We work hard at pretty formatting here | |
510 | * as lines tend to be lost in blocks. | |
511 | * | |
512 | * This only seems to happen on very heavily loaded systems, and | |
513 | * not very often. | |
514 | */ | |
515 | scrapbad() | |
516 | { | |
517 | register line *ip; | |
518 | struct stat stbuf; | |
519 | off_t size, maxt; | |
520 | int bno, cnt, bad, was; | |
521 | char bk[BUFSIZ]; | |
522 | ||
523 | ignore(fstat(tfile, &stbuf)); | |
524 | size = stbuf.st_size; | |
44232d5b | 525 | maxt = (size >> SHFT) | (BNDRY-1); |
f3270895 MH |
526 | bno = (maxt >> OFFBTS) & BLKMSK; |
527 | #ifdef DEBUG | |
528 | fprintf(stderr, "size %ld, maxt %o, bno %d\n", size, maxt, bno); | |
529 | #endif | |
530 | ||
531 | /* | |
532 | * Look for a null separating two lines in the temp file; | |
533 | * if last line was split across blocks, then it is lost | |
534 | * if the last block is. | |
535 | */ | |
536 | while (bno > 0) { | |
537 | ignorl(lseek(tfile, (long) BUFSIZ * bno, 0)); | |
538 | cnt = read(tfile, (char *) bk, BUFSIZ); | |
539 | while (cnt > 0) | |
540 | if (bk[--cnt] == 0) | |
541 | goto null; | |
542 | bno--; | |
543 | } | |
544 | null: | |
545 | ||
546 | /* | |
547 | * Magically calculate the largest valid pointer in the temp file, | |
548 | * consing it up from the block number and the count. | |
549 | */ | |
550 | maxt = ((bno << OFFBTS) | (cnt >> SHFT)) & ~1; | |
551 | #ifdef DEBUG | |
552 | fprintf(stderr, "bno %d, cnt %d, maxt %o\n", bno, cnt, maxt); | |
553 | #endif | |
554 | ||
555 | /* | |
556 | * Now cycle through the line pointers, | |
557 | * trashing the Lusers. | |
558 | */ | |
559 | was = bad = 0; | |
560 | for (ip = one; ip <= dol; ip++) | |
561 | if (*ip > maxt) { | |
562 | #ifdef DEBUG | |
563 | fprintf(stderr, "%d bad, %o > %o\n", ip - zero, *ip, maxt); | |
564 | #endif | |
565 | if (was == 0) | |
566 | was = ip - zero; | |
44232d5b | 567 | *ip = ((HBLKS*BUFSIZ)-8) >> SHFT; |
f3270895 MH |
568 | } else if (was) { |
569 | if (bad == 0) | |
570 | fprintf(stderr, " [Lost line(s):"); | |
571 | fprintf(stderr, " %d", was); | |
572 | if ((ip - 1) - zero > was) | |
573 | fprintf(stderr, "-%d", (ip - 1) - zero); | |
574 | bad++; | |
575 | was = 0; | |
576 | } | |
577 | if (was != 0) { | |
578 | if (bad == 0) | |
579 | fprintf(stderr, " [Lost line(s):"); | |
580 | fprintf(stderr, " %d", was); | |
581 | if (dol - zero != was) | |
582 | fprintf(stderr, "-%d", dol - zero); | |
583 | bad++; | |
584 | } | |
585 | if (bad) | |
586 | fprintf(stderr, "]"); | |
587 | } | |
588 | ||
589 | /* | |
590 | * Aw shucks, if we only had a (void) cast. | |
591 | */ | |
592 | #ifdef lint | |
593 | Ignorl(a) | |
594 | long a; | |
595 | { | |
596 | ||
597 | a = a; | |
598 | } | |
599 | ||
600 | Ignore(a) | |
601 | char *a; | |
602 | { | |
603 | ||
604 | a = a; | |
605 | } | |
606 | ||
607 | Ignorf(a) | |
608 | int (*a)(); | |
609 | { | |
610 | ||
611 | a = a; | |
612 | } | |
613 | ||
614 | ignorl(a) | |
615 | long a; | |
616 | { | |
617 | ||
618 | a = a; | |
619 | } | |
620 | #endif | |
621 | ||
622 | int cntch, cntln, cntodd, cntnull; | |
623 | /* | |
624 | * Following routines stolen mercilessly from ex. | |
625 | */ | |
626 | putfile() | |
627 | { | |
628 | line *a1; | |
629 | register char *fp, *lp; | |
630 | register int nib; | |
631 | ||
632 | a1 = addr1; | |
633 | clrstats(); | |
634 | cntln = addr2 - a1 + 1; | |
635 | if (cntln == 0) | |
636 | return; | |
637 | nib = BUFSIZ; | |
638 | fp = genbuf; | |
639 | do { | |
640 | getline(*a1++); | |
641 | lp = linebuf; | |
642 | for (;;) { | |
643 | if (--nib < 0) { | |
644 | nib = fp - genbuf; | |
645 | if (write(io, genbuf, nib) != nib) | |
646 | wrerror(); | |
647 | cntch += nib; | |
648 | nib = 511; | |
649 | fp = genbuf; | |
650 | } | |
651 | if ((*fp++ = *lp++) == 0) { | |
652 | fp[-1] = '\n'; | |
653 | break; | |
654 | } | |
655 | } | |
656 | } while (a1 <= addr2); | |
657 | nib = fp - genbuf; | |
658 | if (write(io, genbuf, nib) != nib) | |
659 | wrerror(); | |
660 | cntch += nib; | |
661 | } | |
662 | ||
663 | wrerror() | |
664 | { | |
665 | ||
666 | syserror(); | |
667 | } | |
668 | ||
669 | clrstats() | |
670 | { | |
671 | ||
672 | ninbuf = 0; | |
673 | cntch = 0; | |
674 | cntln = 0; | |
675 | cntnull = 0; | |
676 | cntodd = 0; | |
677 | } | |
678 | ||
679 | #define READ 0 | |
680 | #define WRITE 1 | |
681 | ||
682 | getline(tl) | |
683 | line tl; | |
684 | { | |
685 | register char *bp, *lp; | |
686 | register int nl; | |
687 | ||
688 | lp = linebuf; | |
689 | bp = getblock(tl, READ); | |
690 | nl = nleft; | |
691 | tl &= ~OFFMSK; | |
692 | while (*lp++ = *bp++) | |
693 | if (--nl == 0) { | |
694 | bp = getblock(tl += INCRMT, READ); | |
695 | nl = nleft; | |
696 | } | |
697 | } | |
698 | ||
699 | int read(); | |
700 | int write(); | |
701 | ||
702 | char * | |
703 | getblock(atl, iof) | |
704 | line atl; | |
705 | int iof; | |
706 | { | |
707 | register int bno, off; | |
708 | ||
709 | bno = (atl >> OFFBTS) & BLKMSK; | |
710 | off = (atl << SHFT) & LBTMSK; | |
711 | if (bno >= NMBLKS) | |
712 | error(" Tmp file too large"); | |
713 | nleft = BUFSIZ - off; | |
714 | if (bno == iblock) { | |
715 | ichanged |= iof; | |
716 | return (ibuff + off); | |
717 | } | |
718 | if (bno == oblock) | |
719 | return (obuff + off); | |
720 | if (iof == READ) { | |
721 | if (ichanged) | |
722 | blkio(iblock, ibuff, write); | |
723 | ichanged = 0; | |
724 | iblock = bno; | |
725 | blkio(bno, ibuff, read); | |
726 | return (ibuff + off); | |
727 | } | |
728 | if (oblock >= 0) | |
729 | blkio(oblock, obuff, write); | |
730 | oblock = bno; | |
731 | return (obuff + off); | |
732 | } | |
733 | ||
734 | blkio(b, buf, iofcn) | |
735 | short b; | |
736 | char *buf; | |
737 | int (*iofcn)(); | |
738 | { | |
739 | ||
740 | lseek(tfile, (long) (unsigned) b * BUFSIZ, 0); | |
44232d5b | 741 | if ((*iofcn)(tfile, buf, BUFSIZ) != BUFSIZ) |
f3270895 MH |
742 | syserror(); |
743 | } | |
744 | ||
745 | syserror() | |
746 | { | |
747 | extern int sys_nerr; | |
748 | extern char *sys_errlist[]; | |
749 | ||
750 | dirtcnt = 0; | |
751 | write(2, " ", 1); | |
752 | if (errno >= 0 && errno <= sys_nerr) | |
753 | error(sys_errlist[errno]); | |
754 | else | |
755 | error("System error %d", errno); | |
756 | exit(1); | |
757 | } |