1 /* $NetBSD: ch.c,v 1.5 2023/10/06 05:49:49 simonb Exp $ */ 2 3 /* 4 * Copyright (C) 1984-2023 Mark Nudelman 5 * 6 * You may distribute under the terms of either the GNU General Public 7 * License or the Less License, as specified in the README file. 8 * 9 * For more information, see the README file. 10 */ 11 12 13 /* 14 * Low level character input from the input file. 15 * We use these special purpose routines which optimize moving 16 * both forward and backward from the current read pointer. 17 */ 18 19 #include "less.h" 20 #if MSDOS_COMPILER==WIN32C 21 #include <errno.h> 22 #include <windows.h> 23 #endif 24 25 #if HAVE_PROCFS 26 #include <sys/statfs.h> 27 #if HAVE_LINUX_MAGIC_H 28 #include <linux/magic.h> 29 #endif 30 #endif 31 32 typedef POSITION BLOCKNUM; 33 34 public int ignore_eoi; 35 36 /* 37 * Pool of buffers holding the most recently used blocks of the input file. 38 * The buffer pool is kept as a doubly-linked circular list, 39 * in order from most- to least-recently used. 40 * The circular list is anchored by the file state "thisfile". 41 */ 42 struct bufnode { 43 struct bufnode *next, *prev; 44 struct bufnode *hnext, *hprev; 45 }; 46 47 #define LBUFSIZE 8192 48 struct buf { 49 struct bufnode node; 50 BLOCKNUM block; 51 unsigned int datasize; 52 unsigned char data[LBUFSIZE]; 53 }; 54 #define bufnode_buf(bn) ((struct buf *) bn) 55 56 /* 57 * The file state is maintained in a filestate structure. 58 * A pointer to the filestate is kept in the ifile structure. 59 */ 60 #define BUFHASH_SIZE 1024 61 struct filestate { 62 struct bufnode buflist; 63 struct bufnode hashtbl[BUFHASH_SIZE]; 64 int file; 65 int flags; 66 POSITION fpos; 67 int nbufs; 68 BLOCKNUM block; 69 unsigned int offset; 70 POSITION fsize; 71 }; 72 73 #define ch_bufhead thisfile->buflist.next 74 #define ch_buftail thisfile->buflist.prev 75 #define ch_nbufs thisfile->nbufs 76 #define ch_block thisfile->block 77 #define ch_offset thisfile->offset 78 #define ch_fpos thisfile->fpos 79 #define ch_fsize thisfile->fsize 80 #define ch_flags thisfile->flags 81 #define ch_file thisfile->file 82 83 #define END_OF_CHAIN (&thisfile->buflist) 84 #define END_OF_HCHAIN(h) (&thisfile->hashtbl[h]) 85 #define BUFHASH(blk) ((blk) & (BUFHASH_SIZE-1)) 86 87 /* 88 * Macros to manipulate the list of buffers in thisfile->buflist. 89 */ 90 #define FOR_BUFS(bn) \ 91 for (bn = ch_bufhead; bn != END_OF_CHAIN; bn = bn->next) 92 93 #define BUF_RM(bn) \ 94 (bn)->next->prev = (bn)->prev; \ 95 (bn)->prev->next = (bn)->next; 96 97 #define BUF_INS_HEAD(bn) \ 98 (bn)->next = ch_bufhead; \ 99 (bn)->prev = END_OF_CHAIN; \ 100 ch_bufhead->prev = (bn); \ 101 ch_bufhead = (bn); 102 103 #define BUF_INS_TAIL(bn) \ 104 (bn)->next = END_OF_CHAIN; \ 105 (bn)->prev = ch_buftail; \ 106 ch_buftail->next = (bn); \ 107 ch_buftail = (bn); 108 109 /* 110 * Macros to manipulate the list of buffers in thisfile->hashtbl[n]. 111 */ 112 #define FOR_BUFS_IN_CHAIN(h,bn) \ 113 for (bn = thisfile->hashtbl[h].hnext; \ 114 bn != END_OF_HCHAIN(h); bn = bn->hnext) 115 116 #define BUF_HASH_RM(bn) \ 117 (bn)->hnext->hprev = (bn)->hprev; \ 118 (bn)->hprev->hnext = (bn)->hnext; 119 120 #define BUF_HASH_INS(bn,h) \ 121 (bn)->hnext = thisfile->hashtbl[h].hnext; \ 122 (bn)->hprev = END_OF_HCHAIN(h); \ 123 thisfile->hashtbl[h].hnext->hprev = (bn); \ 124 thisfile->hashtbl[h].hnext = (bn); 125 126 static struct filestate *thisfile; 127 static int ch_ungotchar = -1; 128 static int maxbufs = -1; 129 130 extern int autobuf; 131 extern int sigs; 132 extern int secure; 133 extern int screen_trashed; 134 extern int follow_mode; 135 extern int waiting_for_data; 136 extern constant char helpdata[]; 137 extern constant int size_helpdata; 138 extern IFILE curr_ifile; 139 #if LOGFILE 140 extern int logfile; 141 extern char *namelogfile; 142 #endif 143 144 static int ch_addbuf(void); 145 146 147 /* 148 * Get the character pointed to by the read pointer. 149 */ 150 static int ch_get(void) 151 { 152 struct buf *bp; 153 struct bufnode *bn; 154 int n; 155 int read_again; 156 int h; 157 POSITION pos; 158 POSITION len; 159 160 if (thisfile == NULL) 161 return (EOI); 162 163 /* 164 * Quick check for the common case where 165 * the desired char is in the head buffer. 166 */ 167 if (ch_bufhead != END_OF_CHAIN) 168 { 169 bp = bufnode_buf(ch_bufhead); 170 if (ch_block == bp->block && ch_offset < bp->datasize) 171 return bp->data[ch_offset]; 172 } 173 174 /* 175 * Look for a buffer holding the desired block. 176 */ 177 waiting_for_data = FALSE; 178 h = BUFHASH(ch_block); 179 FOR_BUFS_IN_CHAIN(h, bn) 180 { 181 bp = bufnode_buf(bn); 182 if (bp->block == ch_block) 183 { 184 if (ch_offset >= bp->datasize) 185 /* 186 * Need more data in this buffer. 187 */ 188 break; 189 goto found; 190 } 191 } 192 if (bn == END_OF_HCHAIN(h)) 193 { 194 /* 195 * Block is not in a buffer. 196 * Take the least recently used buffer 197 * and read the desired block into it. 198 * If the LRU buffer has data in it, 199 * then maybe allocate a new buffer. 200 */ 201 if (ch_buftail == END_OF_CHAIN || 202 bufnode_buf(ch_buftail)->block != -1) 203 { 204 /* 205 * There is no empty buffer to use. 206 * Allocate a new buffer if: 207 * 1. We can't seek on this file and -b is not in effect; or 208 * 2. We haven't allocated the max buffers for this file yet. 209 */ 210 if ((autobuf && !(ch_flags & CH_CANSEEK)) || 211 (maxbufs < 0 || ch_nbufs < maxbufs)) 212 if (ch_addbuf()) 213 /* 214 * Allocation failed: turn off autobuf. 215 */ 216 autobuf = OPT_OFF; 217 } 218 bn = ch_buftail; 219 bp = bufnode_buf(bn); 220 BUF_HASH_RM(bn); /* Remove from old hash chain. */ 221 bp->block = ch_block; 222 bp->datasize = 0; 223 BUF_HASH_INS(bn, h); /* Insert into new hash chain. */ 224 } 225 226 for (;;) 227 { 228 pos = (ch_block * LBUFSIZE) + bp->datasize; 229 if ((len = ch_length()) != NULL_POSITION && pos >= len) 230 /* 231 * At end of file. 232 */ 233 return (EOI); 234 235 if (pos != ch_fpos) 236 { 237 /* 238 * Not at the correct position: must seek. 239 * If input is a pipe, we're in trouble (can't seek on a pipe). 240 * Some data has been lost: just return "?". 241 */ 242 if (!(ch_flags & CH_CANSEEK)) 243 return ('?'); 244 if (lseek(ch_file, (off_t)pos, SEEK_SET) == BAD_LSEEK) 245 { 246 error("seek error", NULL_PARG); 247 clear_eol(); 248 return (EOI); 249 } 250 ch_fpos = pos; 251 } 252 253 /* 254 * Read the block. 255 * If we read less than a full block, that's ok. 256 * We use partial block and pick up the rest next time. 257 */ 258 if (ch_ungotchar != -1) 259 { 260 bp->data[bp->datasize] = ch_ungotchar; 261 n = 1; 262 ch_ungotchar = -1; 263 } else if (ch_flags & CH_HELPFILE) 264 { 265 bp->data[bp->datasize] = helpdata[ch_fpos]; 266 n = 1; 267 } else 268 { 269 n = iread(ch_file, &bp->data[bp->datasize], 270 (unsigned int)(LBUFSIZE - bp->datasize)); 271 } 272 273 read_again = FALSE; 274 if (n == READ_INTR) 275 { 276 ch_fsize = pos; 277 return (EOI); 278 } 279 if (n == READ_AGAIN) 280 { 281 read_again = TRUE; 282 n = 0; 283 } 284 if (n < 0) 285 { 286 #if MSDOS_COMPILER==WIN32C 287 if (errno != EPIPE) 288 #endif 289 { 290 error("read error", NULL_PARG); 291 clear_eol(); 292 } 293 n = 0; 294 } 295 296 #if LOGFILE 297 /* 298 * If we have a log file, write the new data to it. 299 */ 300 if (!secure && logfile >= 0 && n > 0) 301 write(logfile, (char *) &bp->data[bp->datasize], n); 302 #endif 303 304 ch_fpos += n; 305 bp->datasize += n; 306 307 if (n == 0) 308 { 309 /* Either end of file or no data available. 310 * read_again indicates the latter. */ 311 if (!read_again) 312 ch_fsize = pos; 313 if (ignore_eoi || read_again) 314 { 315 /* Wait a while, then try again. */ 316 if (!waiting_for_data) 317 { 318 PARG parg; 319 parg.p_string = wait_message(); 320 ixerror("%s", &parg); 321 waiting_for_data = TRUE; 322 } 323 sleep_ms(50); /* Reduce system load */ 324 } 325 if (ignore_eoi && follow_mode == FOLLOW_NAME && curr_ifile_changed()) 326 { 327 /* screen_trashed=2 causes make_display to reopen the file. */ 328 screen_trashed = 2; 329 return (EOI); 330 } 331 if (sigs) 332 return (EOI); 333 } 334 335 found: 336 if (ch_bufhead != bn) 337 { 338 /* 339 * Move the buffer to the head of the buffer chain. 340 * This orders the buffer chain, most- to least-recently used. 341 */ 342 BUF_RM(bn); 343 BUF_INS_HEAD(bn); 344 345 /* 346 * Move to head of hash chain too. 347 */ 348 BUF_HASH_RM(bn); 349 BUF_HASH_INS(bn, h); 350 } 351 352 if (ch_offset < bp->datasize) 353 break; 354 /* 355 * After all that, we still don't have enough data. 356 * Go back and try again. 357 */ 358 } 359 return (bp->data[ch_offset]); 360 } 361 362 /* 363 * ch_ungetchar is a rather kludgy and limited way to push 364 * a single char onto an input file descriptor. 365 */ 366 public void ch_ungetchar(int c) 367 { 368 if (c != -1 && ch_ungotchar != -1) 369 error("ch_ungetchar overrun", NULL_PARG); 370 ch_ungotchar = c; 371 } 372 373 #if LOGFILE 374 /* 375 * Close the logfile. 376 * If we haven't read all of standard input into it, do that now. 377 */ 378 public void end_logfile(void) 379 { 380 static int tried = FALSE; 381 382 if (logfile < 0) 383 return; 384 if (!tried && ch_fsize == NULL_POSITION) 385 { 386 tried = TRUE; 387 ierror("Finishing logfile", NULL_PARG); 388 while (ch_forw_get() != EOI) 389 if (ABORT_SIGS()) 390 break; 391 } 392 close(logfile); 393 logfile = -1; 394 free(namelogfile); 395 namelogfile = NULL; 396 } 397 398 /* 399 * Start a log file AFTER less has already been running. 400 * Invoked from the - command; see toggle_option(). 401 * Write all the existing buffered data to the log file. 402 */ 403 public void sync_logfile(void) 404 { 405 struct buf *bp; 406 struct bufnode *bn; 407 int warned = FALSE; 408 BLOCKNUM block; 409 BLOCKNUM nblocks; 410 411 if (logfile < 0) 412 return; 413 nblocks = (ch_fpos + LBUFSIZE - 1) / LBUFSIZE; 414 for (block = 0; block < nblocks; block++) 415 { 416 int wrote = FALSE; 417 FOR_BUFS(bn) 418 { 419 bp = bufnode_buf(bn); 420 if (bp->block == block) 421 { 422 write(logfile, (char *) bp->data, bp->datasize); 423 wrote = TRUE; 424 break; 425 } 426 } 427 if (!wrote && !warned) 428 { 429 error("Warning: log file is incomplete", 430 NULL_PARG); 431 warned = TRUE; 432 } 433 } 434 } 435 436 #endif 437 438 /* 439 * Determine if a specific block is currently in one of the buffers. 440 */ 441 static int buffered(BLOCKNUM block) 442 { 443 struct buf *bp; 444 struct bufnode *bn; 445 int h; 446 447 h = BUFHASH(block); 448 FOR_BUFS_IN_CHAIN(h, bn) 449 { 450 bp = bufnode_buf(bn); 451 if (bp->block == block) 452 return (TRUE); 453 } 454 return (FALSE); 455 } 456 457 /* 458 * Seek to a specified position in the file. 459 * Return 0 if successful, non-zero if can't seek there. 460 */ 461 public int ch_seek(POSITION pos) 462 { 463 BLOCKNUM new_block; 464 POSITION len; 465 466 if (thisfile == NULL) 467 return (0); 468 469 len = ch_length(); 470 if (pos < ch_zero() || (len != NULL_POSITION && pos > len)) 471 return (1); 472 473 new_block = pos / LBUFSIZE; 474 if (!(ch_flags & CH_CANSEEK) && pos != ch_fpos && !buffered(new_block)) 475 { 476 if (ch_fpos > pos) 477 return (1); 478 while (ch_fpos < pos) 479 { 480 if (ch_forw_get() == EOI) 481 return (1); 482 if (ABORT_SIGS()) 483 return (1); 484 } 485 return (0); 486 } 487 /* 488 * Set read pointer. 489 */ 490 ch_block = new_block; 491 ch_offset = pos % LBUFSIZE; 492 return (0); 493 } 494 495 /* 496 * Seek to the end of the file. 497 */ 498 public int ch_end_seek(void) 499 { 500 POSITION len; 501 502 if (thisfile == NULL) 503 return (0); 504 505 if (ch_flags & CH_CANSEEK) 506 ch_fsize = filesize(ch_file); 507 508 len = ch_length(); 509 if (len != NULL_POSITION) 510 return (ch_seek(len)); 511 512 /* 513 * Do it the slow way: read till end of data. 514 */ 515 while (ch_forw_get() != EOI) 516 if (ABORT_SIGS()) 517 return (1); 518 return (0); 519 } 520 521 /* 522 * Seek to the last position in the file that is currently buffered. 523 */ 524 public int ch_end_buffer_seek(void) 525 { 526 struct buf *bp; 527 struct bufnode *bn; 528 POSITION buf_pos; 529 POSITION end_pos; 530 531 if (thisfile == NULL || (ch_flags & CH_CANSEEK)) 532 return (ch_end_seek()); 533 534 end_pos = 0; 535 FOR_BUFS(bn) 536 { 537 bp = bufnode_buf(bn); 538 buf_pos = (bp->block * LBUFSIZE) + bp->datasize; 539 if (buf_pos > end_pos) 540 end_pos = buf_pos; 541 } 542 543 return (ch_seek(end_pos)); 544 } 545 546 /* 547 * Seek to the beginning of the file, or as close to it as we can get. 548 * We may not be able to seek there if input is a pipe and the 549 * beginning of the pipe is no longer buffered. 550 */ 551 public int ch_beg_seek(void) 552 { 553 struct bufnode *bn; 554 struct bufnode *firstbn; 555 556 /* 557 * Try a plain ch_seek first. 558 */ 559 if (ch_seek(ch_zero()) == 0) 560 return (0); 561 562 /* 563 * Can't get to position 0. 564 * Look thru the buffers for the one closest to position 0. 565 */ 566 firstbn = ch_bufhead; 567 if (firstbn == END_OF_CHAIN) 568 return (1); 569 FOR_BUFS(bn) 570 { 571 if (bufnode_buf(bn)->block < bufnode_buf(firstbn)->block) 572 firstbn = bn; 573 } 574 ch_block = bufnode_buf(firstbn)->block; 575 ch_offset = 0; 576 return (0); 577 } 578 579 /* 580 * Return the length of the file, if known. 581 */ 582 public POSITION ch_length(void) 583 { 584 if (thisfile == NULL) 585 return (NULL_POSITION); 586 if (ignore_eoi) 587 return (NULL_POSITION); 588 if (ch_flags & CH_HELPFILE) 589 return (size_helpdata); 590 if (ch_flags & CH_NODATA) 591 return (0); 592 return (ch_fsize); 593 } 594 595 /* 596 * Return the current position in the file. 597 */ 598 public POSITION ch_tell(void) 599 { 600 if (thisfile == NULL) 601 return (NULL_POSITION); 602 return (ch_block * LBUFSIZE) + ch_offset; 603 } 604 605 /* 606 * Get the current char and post-increment the read pointer. 607 */ 608 public int ch_forw_get(void) 609 { 610 int c; 611 612 if (thisfile == NULL) 613 return (EOI); 614 c = ch_get(); 615 if (c == EOI) 616 return (EOI); 617 if (ch_offset < LBUFSIZE-1) 618 ch_offset++; 619 else 620 { 621 ch_block ++; 622 ch_offset = 0; 623 } 624 return (c); 625 } 626 627 /* 628 * Pre-decrement the read pointer and get the new current char. 629 */ 630 public int ch_back_get(void) 631 { 632 if (thisfile == NULL) 633 return (EOI); 634 if (ch_offset > 0) 635 ch_offset --; 636 else 637 { 638 if (ch_block <= 0) 639 return (EOI); 640 if (!(ch_flags & CH_CANSEEK) && !buffered(ch_block-1)) 641 return (EOI); 642 ch_block--; 643 ch_offset = LBUFSIZE-1; 644 } 645 return (ch_get()); 646 } 647 648 /* 649 * Set max amount of buffer space. 650 * bufspace is in units of 1024 bytes. -1 mean no limit. 651 */ 652 public void ch_setbufspace(int bufspace) 653 { 654 if (bufspace < 0) 655 maxbufs = -1; 656 else 657 { 658 int lbufk = LBUFSIZE / 1024; 659 maxbufs = bufspace / lbufk + (bufspace % lbufk != 0); 660 if (maxbufs < 1) 661 maxbufs = 1; 662 } 663 } 664 665 /* 666 * Flush (discard) any saved file state, including buffer contents. 667 */ 668 public void ch_flush(void) 669 { 670 struct bufnode *bn; 671 672 if (thisfile == NULL) 673 return; 674 675 if (!(ch_flags & CH_CANSEEK)) 676 { 677 /* 678 * If input is a pipe, we don't flush buffer contents, 679 * since the contents can't be recovered. 680 */ 681 ch_fsize = NULL_POSITION; 682 return; 683 } 684 685 /* 686 * Initialize all the buffers. 687 */ 688 FOR_BUFS(bn) 689 { 690 bufnode_buf(bn)->block = -1; 691 } 692 693 /* 694 * Figure out the size of the file, if we can. 695 */ 696 ch_fsize = filesize(ch_file); 697 698 /* 699 * Seek to a known position: the beginning of the file. 700 */ 701 ch_fpos = 0; 702 ch_block = 0; /* ch_fpos / LBUFSIZE; */ 703 ch_offset = 0; /* ch_fpos % LBUFSIZE; */ 704 705 #if HAVE_PROCFS 706 /* 707 * This is a kludge to workaround a Linux kernel bug: files in 708 * /proc have a size of 0 according to fstat() but have readable 709 * data. They are sometimes, but not always, seekable. 710 * Force them to be non-seekable here. 711 */ 712 if (ch_fsize == 0) 713 { 714 struct statfs st; 715 if (fstatfs(ch_file, &st) == 0) 716 { 717 if (st.f_type == PROC_SUPER_MAGIC) 718 { 719 ch_fsize = NULL_POSITION; 720 ch_flags &= ~CH_CANSEEK; 721 } 722 } 723 } 724 #endif 725 726 if (lseek(ch_file, (off_t)0, SEEK_SET) == BAD_LSEEK) 727 { 728 /* 729 * Warning only; even if the seek fails for some reason, 730 * there's a good chance we're at the beginning anyway. 731 * {{ I think this is bogus reasoning. }} 732 */ 733 error("seek error to 0", NULL_PARG); 734 } 735 } 736 737 /* 738 * Allocate a new buffer. 739 * The buffer is added to the tail of the buffer chain. 740 */ 741 static int ch_addbuf(void) 742 { 743 struct buf *bp; 744 struct bufnode *bn; 745 746 /* 747 * Allocate and initialize a new buffer and link it 748 * onto the tail of the buffer list. 749 */ 750 bp = (struct buf *) calloc(1, sizeof(struct buf)); 751 if (bp == NULL) 752 return (1); 753 ch_nbufs++; 754 bp->block = -1; 755 bn = &bp->node; 756 757 BUF_INS_TAIL(bn); 758 BUF_HASH_INS(bn, 0); 759 return (0); 760 } 761 762 /* 763 * 764 */ 765 static void init_hashtbl(void) 766 { 767 int h; 768 769 for (h = 0; h < BUFHASH_SIZE; h++) 770 { 771 thisfile->hashtbl[h].hnext = END_OF_HCHAIN(h); 772 thisfile->hashtbl[h].hprev = END_OF_HCHAIN(h); 773 } 774 } 775 776 /* 777 * Delete all buffers for this file. 778 */ 779 static void ch_delbufs(void) 780 { 781 struct bufnode *bn; 782 783 while (ch_bufhead != END_OF_CHAIN) 784 { 785 bn = ch_bufhead; 786 BUF_RM(bn); 787 free(bufnode_buf(bn)); 788 } 789 ch_nbufs = 0; 790 init_hashtbl(); 791 } 792 793 /* 794 * Is it possible to seek on a file descriptor? 795 */ 796 public int seekable(int f) 797 { 798 #if MSDOS_COMPILER 799 extern int fd0; 800 if (f == fd0 && !isatty(fd0)) 801 { 802 /* 803 * In MS-DOS, pipes are seekable. Check for 804 * standard input, and pretend it is not seekable. 805 */ 806 return (0); 807 } 808 #endif 809 return (lseek(f, (off_t)1, SEEK_SET) != BAD_LSEEK); 810 } 811 812 /* 813 * Force EOF to be at the current read position. 814 * This is used after an ignore_eof read, during which the EOF may change. 815 */ 816 public void ch_set_eof(void) 817 { 818 if (ch_fsize != NULL_POSITION && ch_fsize < ch_fpos) 819 ch_fsize = ch_fpos; 820 } 821 822 823 /* 824 * Initialize file state for a new file. 825 */ 826 public void ch_init(int f, int flags) 827 { 828 /* 829 * See if we already have a filestate for this file. 830 */ 831 thisfile = (struct filestate *) get_filestate(curr_ifile); 832 if (thisfile == NULL) 833 { 834 /* 835 * Allocate and initialize a new filestate. 836 */ 837 thisfile = (struct filestate *) 838 ecalloc(1, sizeof(struct filestate)); 839 thisfile->buflist.next = thisfile->buflist.prev = END_OF_CHAIN; 840 thisfile->nbufs = 0; 841 thisfile->flags = flags; 842 thisfile->fpos = 0; 843 thisfile->block = 0; 844 thisfile->offset = 0; 845 thisfile->file = -1; 846 thisfile->fsize = NULL_POSITION; 847 init_hashtbl(); 848 /* 849 * Try to seek; set CH_CANSEEK if it works. 850 */ 851 if ((flags & CH_CANSEEK) && !seekable(f)) 852 ch_flags &= ~CH_CANSEEK; 853 set_filestate(curr_ifile, (void *) thisfile); 854 } 855 if (thisfile->file == -1) 856 thisfile->file = f; 857 ch_flush(); 858 } 859 860 /* 861 * Close a filestate. 862 */ 863 public void ch_close(void) 864 { 865 int keepstate = FALSE; 866 867 if (thisfile == NULL) 868 return; 869 870 if ((ch_flags & (CH_CANSEEK|CH_POPENED|CH_HELPFILE)) && !(ch_flags & CH_KEEPOPEN)) 871 { 872 /* 873 * We can seek or re-open, so we don't need to keep buffers. 874 */ 875 ch_delbufs(); 876 } else 877 keepstate = TRUE; 878 if (!(ch_flags & CH_KEEPOPEN)) 879 { 880 /* 881 * We don't need to keep the file descriptor open 882 * (because we can re-open it.) 883 * But don't really close it if it was opened via popen(), 884 * because pclose() wants to close it. 885 */ 886 if (!(ch_flags & (CH_POPENED|CH_HELPFILE))) 887 close(ch_file); 888 ch_file = -1; 889 } else 890 keepstate = TRUE; 891 if (!keepstate) 892 { 893 /* 894 * We don't even need to keep the filestate structure. 895 */ 896 free(thisfile); 897 thisfile = NULL; 898 set_filestate(curr_ifile, (void *) NULL); 899 } 900 } 901 902 /* 903 * Return ch_flags for the current file. 904 */ 905 public int ch_getflags(void) 906 { 907 if (thisfile == NULL) 908 return (0); 909 return (ch_flags); 910 } 911 912 #if 0 913 static void ch_dump(struct filestate *fs) 914 { 915 struct buf *bp; 916 struct bufnode *bn; 917 unsigned char *s; 918 919 if (fs == NULL) 920 { 921 printf(" --no filestate\n"); 922 return; 923 } 924 printf(" file %d, flags %x, fpos %x, fsize %x, blk/off %x/%x\n", 925 fs->file, fs->flags, fs->fpos, 926 fs->fsize, fs->block, fs->offset); 927 printf(" %d bufs:\n", fs->nbufs); 928 for (bn = fs->next; bn != &fs->buflist; bn = bn->next) 929 { 930 bp = bufnode_buf(bn); 931 printf("%x: blk %x, size %x \"", 932 bp, bp->block, bp->datasize); 933 for (s = bp->data; s < bp->data + 30; s++) 934 if (*s >= ' ' && *s < 0x7F) 935 printf("%c", *s); 936 else 937 printf("."); 938 printf("\"\n"); 939 } 940 } 941 #endif 942