debugfs/logdump.c

   1 /*
   2  * logdump.c --- dump the contents of the journal out to a file
   3  *
   4  * Authro: Stephen C. Tweedie, 2001  <sct@redhat.com>
   5  * Copyright (C) 2001 Red Hat, Inc.
   6  * Based on portions  Copyright (C) 1994 Theodore Ts'o.
   7  *
   8  * This file may be redistributed under the terms of the GNU Public
   9  * License.
  10  */
  11
  12 #include <stdio.h>
  13 #include <unistd.h>
  14 #include <stdlib.h>
  15 #include <ctype.h>
  16 #include <string.h>
  17 #include <time.h>
  18 #ifdef HAVE_ERRNO_H
  19 #include <errno.h>
  20 #endif
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23 #include <fcntl.h>
  24 #include <utime.h>
  25 #ifdef HAVE_GETOPT_H
  26 #include <getopt.h>
  27 #else
  28 extern int optind;
  29 extern char *optarg;
  30 #endif
  31
  32 #include "debugfs.h"
  33 #include "blkid/blkid.h"
  34 #include "jfs_user.h"
  35 #include <uuid/uuid.h>
  36
  37 enum journal_location {JOURNAL_IS_INTERNAL, JOURNAL_IS_EXTERNAL};
  38
  39 #define ANY_BLOCK ((unsigned int) -1)
  40
  41 int             dump_all, dump_contents, dump_descriptors;
  42 unsigned int    block_to_dump, group_to_dump, bitmap_to_dump;
  43 unsigned int    inode_block_to_dump, inode_offset_to_dump, bitmap_to_dump;
  44 ext2_ino_t      inode_to_dump;
  45
  46 struct journal_source
  47 {
  48         enum journal_location where;
  49         int fd;
  50         ext2_file_t file;
  51 };
  52
  53 static void dump_journal(char *, FILE *, struct journal_source *);
  54
  55 static void dump_descriptor_block(FILE *, struct journal_source *,
  56                                   char *, journal_superblock_t *,
  57                                   unsigned int *, int, tid_t);
  58
  59 static void dump_revoke_block(FILE *, char *, journal_superblock_t *,
  60                                   unsigned int, int, tid_t);
  61
  62 static void dump_metadata_block(FILE *, struct journal_source *,
  63                                 journal_superblock_t*,
  64                                 unsigned int, unsigned int, int, tid_t);
  65
  66 static void do_hexdump (FILE *, char *, int);
  67
  68 #define WRAP(jsb, blocknr)                                      \
  69         if (blocknr >= be32_to_cpu((jsb)->s_maxlen))            \
  70                 blocknr -= (be32_to_cpu((jsb)->s_maxlen) -      \
  71                             be32_to_cpu((jsb)->s_first));
  72
  73 void do_logdump(int argc, char **argv)
  74 {
  75         int             c;
  76         int             retval;
  77         char            *out_fn;
  78         FILE            *out_file;
  79
  80         char            *inode_spec = NULL;
  81         char            *journal_fn = NULL;
  82         int             journal_fd = 0;
  83         int             use_sb = 0;
  84         ext2_ino_t      journal_inum;
  85         struct ext2_inode journal_inode;
  86         ext2_file_t     journal_file;
  87         char            *tmp;
  88         struct journal_source journal_source;
  89         struct ext2_super_block *es = NULL;
  90
  91         journal_source.where = 0;
  92         journal_source.fd = 0;
  93         journal_source.file = 0;
  94         dump_all = 0;
  95         dump_contents = 0;
  96         dump_descriptors = 1;
  97         block_to_dump = ANY_BLOCK;
  98         bitmap_to_dump = -1;
  99         inode_block_to_dump = ANY_BLOCK;
 100         inode_to_dump = -1;
 101
 102         reset_getopt();
 103         while ((c = getopt (argc, argv, "ab:ci:f:s")) != EOF) {
 104                 switch (c) {
 105                 case 'a':
 106                         dump_all++;
 107                         break;
 108                 case 'b':
 109                         block_to_dump = strtoul(optarg, &tmp, 0);
 110                         if (*tmp) {
 111                                 com_err(argv[0], 0,
 112                                         "Bad block number - %s", optarg);
 113                                 return;
 114                         }
 115                         dump_descriptors = 0;
 116                         break;
 117                 case 'c':
 118                         dump_contents++;
 119                         break;
 120                 case 'f':
 121                         journal_fn = optarg;
 122                         break;
 123                 case 'i':
 124                         inode_spec = optarg;
 125                         dump_descriptors = 0;
 126                         break;
 127                 case 's':
 128                         use_sb++;
 129                         break;
 130                 default:
 131                         goto print_usage;
 132                 }
 133         }
 134         if (optind != argc && optind != argc-1) {
 135                 goto print_usage;
 136         }
 137
 138         if (current_fs)
 139                 es = current_fs->super;
 140
 141         if (inode_spec) {
 142                 int inode_group, group_offset, inodes_per_block;
 143
 144                 if (check_fs_open(argv[0]))
 145                         return;
 146
 147                 inode_to_dump = string_to_inode(inode_spec);
 148                 if (!inode_to_dump)
 149                         return;
 150
 151                 inode_group = ((inode_to_dump - 1)
 152                                / es->s_inodes_per_group);
 153                 group_offset = ((inode_to_dump - 1)
 154                                 % es->s_inodes_per_group);
 155                 inodes_per_block = (current_fs->blocksize
 156                                     / sizeof(struct ext2_inode));
 157
 158                 inode_block_to_dump =
 159                         current_fs->group_desc[inode_group].bg_inode_table +
 160                         (group_offset / inodes_per_block);
 161                 inode_offset_to_dump = ((group_offset % inodes_per_block)
 162                                         * sizeof(struct ext2_inode));
 163                 printf("Inode %u is at group %u, block %u, offset %u\n",
 164                        inode_to_dump, inode_group,
 165                        inode_block_to_dump, inode_offset_to_dump);
 166         }
 167
 168         if (optind == argc) {
 169                 out_file = stdout;
 170         } else {
 171                 out_fn = argv[optind];
 172                 out_file = fopen(out_fn, "w");
 173                 if (!out_file) {
 174                         com_err(argv[0], errno, "while opening %s for logdump",
 175                                 out_fn);
 176                         goto errout;
 177                 }
 178         }
 179
 180         if (block_to_dump != ANY_BLOCK && current_fs != NULL) {
 181                 group_to_dump = ((block_to_dump -
 182                                   es->s_first_data_block)
 183                                  / es->s_blocks_per_group);
 184                 bitmap_to_dump = current_fs->group_desc[group_to_dump].bg_block_bitmap;
 185         }
 186
 187         if (!journal_fn && check_fs_open(argv[0]))
 188                 goto errout;
 189
 190         if (journal_fn) {
 191                 /* Set up to read journal from a regular file somewhere */
 192                 journal_fd = open(journal_fn, O_RDONLY, 0);
 193                 if (journal_fd < 0) {
 194                         com_err(argv[0], errno, "while opening %s for logdump",
 195                                 journal_fn);
 196                         goto errout;
 197                 }
 198
 199                 journal_source.where = JOURNAL_IS_EXTERNAL;
 200                 journal_source.fd = journal_fd;
 201         } else if ((journal_inum = es->s_journal_inum)) {
 202                 if (use_sb) {
 203                         if (es->s_jnl_backup_type != EXT3_JNL_BACKUP_BLOCKS) {
 204                                 com_err(argv[0], 0,
 205                                         "no journal backup in super block\n");
 206                                 goto errout;
 207                         }
 208                         memset(&journal_inode, 0, sizeof(struct ext2_inode));
 209                         memcpy(&journal_inode.i_block[0], es->s_jnl_blocks,
 210                                EXT2_N_BLOCKS*4);
 211                         journal_inode.i_size = es->s_jnl_blocks[16];
 212                         journal_inode.i_links_count = 1;
 213                         journal_inode.i_mode = LINUX_S_IFREG | 0600;
 214                 } else {
 215                         if (debugfs_read_inode(journal_inum, &journal_inode,
 216                                                argv[0]))
 217                                 goto errout;
 218                 }
 219
 220                 retval = ext2fs_file_open2(current_fs, journal_inum,
 221                                            &journal_inode, 0, &journal_file);
 222                 if (retval) {
 223                         com_err(argv[0], retval, "while opening ext2 file");
 224                         goto errout;
 225                 }
 226                 journal_source.where = JOURNAL_IS_INTERNAL;
 227                 journal_source.file = journal_file;
 228         } else {
 229                 char uuid[37];
 230
 231                 uuid_unparse(es->s_journal_uuid, uuid);
 232                 journal_fn = blkid_get_devname(NULL, "UUID", uuid);
 233                 if (!journal_fn)
 234                                 journal_fn = blkid_devno_to_devname(es->s_journal_dev);
 235                 if (!journal_fn) {
 236                         com_err(argv[0], 0, "filesystem has no journal");
 237                         goto errout;
 238                 }
 239                 journal_fd = open(journal_fn, O_RDONLY, 0);
 240                 if (journal_fd < 0) {
 241                         com_err(argv[0], errno, "while opening %s for logdump",
 242                                 journal_fn);
 243                         free(journal_fn);
 244                         goto errout;
 245                 }
 246                 fprintf(out_file, "Using external journal found at %s\n",
 247                         journal_fn);
 248                 free(journal_fn);
 249                 journal_source.where = JOURNAL_IS_EXTERNAL;
 250                 journal_source.fd = journal_fd;
 251         }
 252
 253         dump_journal(argv[0], out_file, &journal_source);
 254
 255         if (journal_source.where == JOURNAL_IS_INTERNAL)
 256                 ext2fs_file_close(journal_file);
 257         else
 258                 close(journal_fd);
 259
 260 errout:
 261         if (out_file != stdout)
 262                 fclose(out_file);
 263
 264         return;
 265
 266 print_usage:
 267         fprintf(stderr, "%s: Usage: logdump [-ac] [-b<block>] [-i<inode>]\n\t"
 268                 "[-f<journal_file>] [output_file]\n", argv[0]);
 269 }
 270
 271
 272 static int read_journal_block(const char *cmd, struct journal_source *source,
 273                               off_t offset, char *buf, int size,
 274                               unsigned int *got)
 275 {
 276         int retval;
 277
 278         if (source->where == JOURNAL_IS_EXTERNAL) {
 279                 if (lseek(source->fd, offset, SEEK_SET) < 0) {
 280                         retval = errno;
 281                         com_err(cmd, retval, "while seeking in reading journal");
 282                         return retval;
 283                 }
 284                 retval = read(source->fd, buf, size);
 285                 if (retval >= 0) {
 286                         *got = retval;
 287                         retval = 0;
 288                 } else
 289                         retval = errno;
 290         } else {
 291                 retval = ext2fs_file_lseek(source->file, offset,
 292                                            EXT2_SEEK_SET, NULL);
 293                 if (retval) {
 294                         com_err(cmd, retval, "while seeking in reading journal");
 295                         return retval;
 296                 }
 297
 298                 retval = ext2fs_file_read(source->file, buf, size, got);
 299         }
 300
 301         if (retval)
 302                 com_err(cmd, retval, "while while reading journal");
 303         else if (*got != (unsigned int) size) {
 304                 com_err(cmd, 0, "short read (read %d, expected %d) while while reading journal", *got, size);
 305                 retval = -1;
 306         }
 307
 308         return retval;
 309 }
 310
 311 static const char *type_to_name(int btype)
 312 {
 313         switch (btype) {
 314         case JFS_DESCRIPTOR_BLOCK:
 315                 return "descriptor block";
 316         case JFS_COMMIT_BLOCK:
 317                 return "commit block";
 318         case JFS_SUPERBLOCK_V1:
 319                 return "V1 superblock";
 320         case JFS_SUPERBLOCK_V2:
 321                 return "V2 superblock";
 322         case JFS_REVOKE_BLOCK:
 323                 return "revoke table";
 324         }
 325         return "unrecognised type";
 326 }
 327
 328
 329 static void dump_journal(char *cmdname, FILE *out_file,
 330                          struct journal_source *source)
 331 {
 332         struct ext2_super_block *sb;
 333         char                    jsb_buffer[1024];
 334         char                    buf[8192];
 335         journal_superblock_t    *jsb;
 336         unsigned int            blocksize = 1024;
 337         unsigned int            got;
 338         int                     retval;
 339         __u32                   magic, sequence, blocktype;
 340         journal_header_t        *header;
 341
 342         tid_t                   transaction;
 343         unsigned int            blocknr = 0;
 344
 345         /* First, check to see if there's an ext2 superblock header */
 346         retval = read_journal_block(cmdname, source, 0,
 347                                     buf, 2048, &got);
 348         if (retval)
 349                 return;
 350
 351         jsb = (journal_superblock_t *) buf;
 352         sb = (struct ext2_super_block *) (buf+1024);
 353 #ifdef ENABLE_SWAPFS
 354         if (sb->s_magic == ext2fs_swab16(EXT2_SUPER_MAGIC))
 355                 ext2fs_swap_super(sb);
 356 #endif
 357
 358         if ((be32_to_cpu(jsb->s_header.h_magic) != JFS_MAGIC_NUMBER) &&
 359             (sb->s_magic == EXT2_SUPER_MAGIC) &&
 360             (sb->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)) {
 361                 blocksize = EXT2_BLOCK_SIZE(sb);
 362                 blocknr = (blocksize == 1024) ? 2 : 1;
 363                 uuid_unparse(sb->s_uuid, jsb_buffer);
 364                 fprintf(out_file, "Ext2 superblock header found.\n");
 365                 if (dump_all) {
 366                         fprintf(out_file, "\tuuid=%s\n", jsb_buffer);
 367                         fprintf(out_file, "\tblocksize=%d\n", blocksize);
 368                         fprintf(out_file, "\tjournal data size %ld\n",
 369                                 (long) sb->s_blocks_count);
 370                 }
 371         }
 372
 373         /* Next, read the journal superblock */
 374
 375         retval = read_journal_block(cmdname, source, blocknr*blocksize,
 376                                     jsb_buffer, 1024, &got);
 377         if (retval)
 378                 return;
 379
 380         jsb = (journal_superblock_t *) jsb_buffer;
 381         if (be32_to_cpu(jsb->s_header.h_magic) != JFS_MAGIC_NUMBER) {
 382                 fprintf(out_file,
 383                         "Journal superblock magic number invalid!\n");
 384                 return;
 385         }
 386         blocksize = be32_to_cpu(jsb->s_blocksize);
 387         transaction = be32_to_cpu(jsb->s_sequence);
 388         blocknr = be32_to_cpu(jsb->s_start);
 389
 390         fprintf(out_file, "Journal starts at block %u, transaction %u\n",
 391                 blocknr, transaction);
 392
 393         if (!blocknr)
 394                 /* Empty journal, nothing to do. */
 395                 return;
 396
 397         while (1) {
 398                 retval = read_journal_block(cmdname, source,
 399                                             blocknr*blocksize, buf,
 400                                             blocksize, &got);
 401                 if (retval || got != blocksize)
 402                         return;
 403
 404                 header = (journal_header_t *) buf;
 405
 406                 magic = be32_to_cpu(header->h_magic);
 407                 sequence = be32_to_cpu(header->h_sequence);
 408                 blocktype = be32_to_cpu(header->h_blocktype);
 409
 410                 if (magic != JFS_MAGIC_NUMBER) {
 411                         fprintf (out_file, "No magic number at block %u: "
 412                                  "end of journal.\n", blocknr);
 413                         return;
 414                 }
 415
 416                 if (sequence != transaction) {
 417                         fprintf (out_file, "Found sequence %u (not %u) at "
 418                                  "block %u: end of journal.\n",
 419                                  sequence, transaction, blocknr);
 420                         return;
 421                 }
 422
 423                 if (dump_descriptors) {
 424                         fprintf (out_file, "Found expected sequence %u, "
 425                                  "type %u (%s) at block %u\n",
 426                                  sequence, blocktype,
 427                                  type_to_name(blocktype), blocknr);
 428                 }
 429
 430                 switch (blocktype) {
 431                 case JFS_DESCRIPTOR_BLOCK:
 432                         dump_descriptor_block(out_file, source, buf, jsb,
 433                                               &blocknr, blocksize,
 434                                               transaction);
 435                         continue;
 436
 437                 case JFS_COMMIT_BLOCK:
 438                         transaction++;
 439                         blocknr++;
 440                         WRAP(jsb, blocknr);
 441                         continue;
 442
 443                 case JFS_REVOKE_BLOCK:
 444                         dump_revoke_block(out_file, buf, jsb,
 445                                           blocknr, blocksize,
 446                                           transaction);
 447                         blocknr++;
 448                         WRAP(jsb, blocknr);
 449                         continue;
 450
 451                 default:
 452                         fprintf (out_file, "Unexpected block type %u at "
 453                                  "block %u.\n", blocktype, blocknr);
 454                         return;
 455                 }
 456         }
 457 }
 458
 459
 460 static void dump_descriptor_block(FILE *out_file,
 461                                   struct journal_source *source,
 462                                   char *buf,
 463                                   journal_superblock_t *jsb,
 464                                   unsigned int *blockp, int blocksize,
 465                                   tid_t transaction)
 466 {
 467         int                     offset;
 468         char                    *tagp;
 469         journal_block_tag_t     *tag;
 470         unsigned int            blocknr;
 471         __u32                   tag_block;
 472         __u32                   tag_flags;
 473
 474
 475         offset = sizeof(journal_header_t);
 476         blocknr = *blockp;
 477
 478         if (dump_all)
 479                 fprintf(out_file, "Dumping descriptor block, sequence %u, at "
 480                         "block %u:\n", transaction, blocknr);
 481
 482         ++blocknr;
 483         WRAP(jsb, blocknr);
 484
 485         do {
 486                 /* Work out the location of the current tag, and skip to
 487                  * the next one... */
 488                 tagp = &buf[offset];
 489                 tag = (journal_block_tag_t *) tagp;
 490                 offset += sizeof(journal_block_tag_t);
 491
 492                 /* ... and if we have gone too far, then we've reached the
 493                    end of this block. */
 494                 if (offset > blocksize)
 495                         break;
 496
 497                 tag_block = be32_to_cpu(tag->t_blocknr);
 498                 tag_flags = be32_to_cpu(tag->t_flags);
 499
 500                 if (!(tag_flags & JFS_FLAG_SAME_UUID))
 501                         offset += 16;
 502
 503                 dump_metadata_block(out_file, source, jsb,
 504                                     blocknr, tag_block, blocksize,
 505                                     transaction);
 506
 507                 ++blocknr;
 508                 WRAP(jsb, blocknr);
 509
 510         } while (!(tag_flags & JFS_FLAG_LAST_TAG));
 511
 512         *blockp = blocknr;
 513 }
 514
 515
 516 static void dump_revoke_block(FILE *out_file, char *buf,
 517                               journal_superblock_t *jsb EXT2FS_ATTR((unused)),
 518                               unsigned int blocknr,
 519                               int blocksize EXT2FS_ATTR((unused)),
 520                               tid_t transaction)
 521 {
 522         int                     offset, max;
 523         journal_revoke_header_t *header;
 524         unsigned int            *entry, rblock;
 525
 526         if (dump_all)
 527                 fprintf(out_file, "Dumping revoke block, sequence %u, at "
 528                         "block %u:\n", transaction, blocknr);
 529
 530         header = (journal_revoke_header_t *) buf;
 531         offset = sizeof(journal_revoke_header_t);
 532         max = be32_to_cpu(header->r_count);
 533
 534         while (offset < max) {
 535                 entry = (unsigned int *) (buf + offset);
 536                 rblock = be32_to_cpu(*entry);
 537                 if (dump_all || rblock == block_to_dump) {
 538                         fprintf(out_file, "  Revoke FS block %u", rblock);
 539                         if (dump_all)
 540                                 fprintf(out_file, "\n");
 541                         else
 542                                 fprintf(out_file," at block %u, sequence %u\n",
 543                                         blocknr, transaction);
 544                 }
 545                 offset += 4;
 546         }
 547 }
 548
 549
 550 static void show_extent(FILE *out_file, int start_extent, int end_extent,
 551                         __u32 first_block)
 552 {
 553         if (start_extent >= 0 && first_block != 0)
 554                 fprintf(out_file, "(%d+%u): %u ",
 555                         start_extent, end_extent-start_extent, first_block);
 556 }
 557
 558 static void show_indirect(FILE *out_file, const char *name, __u32 where)
 559 {
 560         if (where)
 561                 fprintf(out_file, "(%s): %u ", name, where);
 562 }
 563
 564
 565 static void dump_metadata_block(FILE *out_file, struct journal_source *source,
 566                                 journal_superblock_t *jsb EXT2FS_ATTR((unused)),
 567                                 unsigned int log_blocknr,
 568                                 unsigned int fs_blocknr,
 569                                 int blocksize,
 570                                 tid_t transaction)
 571 {
 572         unsigned int    got;
 573         int             retval;
 574         char            buf[8192];
 575
 576         if (!(dump_all
 577               || (fs_blocknr == block_to_dump)
 578               || (fs_blocknr == inode_block_to_dump)
 579               || (fs_blocknr == bitmap_to_dump)))
 580                 return;
 581
 582         fprintf(out_file, "  FS block %u logged at ", fs_blocknr);
 583         if (!dump_all)
 584                 fprintf(out_file, "sequence %u, ", transaction);
 585         fprintf(out_file, "journal block %u\n", log_blocknr);
 586
 587         /* There are two major special cases to parse:
 588          *
 589          * If this block is a block
 590          * bitmap block, we need to give it special treatment so that we
 591          * can log any allocates and deallocates which affect the
 592          * block_to_dump query block.
 593          *
 594          * If the block is an inode block for the inode being searched
 595          * for, then we need to dump the contents of that inode
 596          * structure symbolically.
 597          */
 598
 599         if (!(dump_contents && dump_all)
 600             && fs_blocknr != block_to_dump
 601             && fs_blocknr != bitmap_to_dump
 602             && fs_blocknr != inode_block_to_dump)
 603                 return;
 604
 605         retval = read_journal_block("logdump", source,
 606                                     blocksize * log_blocknr,
 607                                     buf, blocksize, &got);
 608         if (retval)
 609                 return;
 610
 611         if (fs_blocknr == bitmap_to_dump) {
 612                 struct ext2_super_block *super;
 613                 int offset;
 614
 615                 super = current_fs->super;
 616                 offset = ((fs_blocknr - super->s_first_data_block) %
 617                           super->s_blocks_per_group);
 618
 619                 fprintf(out_file, "    (block bitmap for block %u: "
 620                         "block is %s)\n",
 621                         block_to_dump,
 622                         ext2fs_test_bit(offset, buf) ? "SET" : "CLEAR");
 623         }
 624
 625         if (fs_blocknr == inode_block_to_dump) {
 626                 struct ext2_inode *inode;
 627                 int first, prev, this, start_extent, i;
 628
 629                 fprintf(out_file, "    (inode block for inode %u):\n",
 630                         inode_to_dump);
 631
 632                 inode = (struct ext2_inode *) (buf + inode_offset_to_dump);
 633                 internal_dump_inode(out_file, "    ", inode_to_dump, inode, 0);
 634
 635                 /* Dump out the direct/indirect blocks here:
 636                  * internal_dump_inode can only dump them from the main
 637                  * on-disk inode, not from the journaled copy of the
 638                  * inode. */
 639
 640                 fprintf (out_file, "    Blocks:  ");
 641                 first = prev = start_extent = -1;
 642
 643                 for (i=0; i<EXT2_NDIR_BLOCKS; i++) {
 644                         this = inode->i_block[i];
 645                         if (start_extent >= 0  && this == prev+1) {
 646                                 prev = this;
 647                                 continue;
 648                         } else {
 649                                 show_extent(out_file, start_extent, i, first);
 650                                 start_extent = i;
 651                                 first = prev = this;
 652                         }
 653                 }
 654                 show_extent(out_file, start_extent, i, first);
 655                 show_indirect(out_file, "IND", inode->i_block[i++]);
 656                 show_indirect(out_file, "DIND", inode->i_block[i++]);
 657                 show_indirect(out_file, "TIND", inode->i_block[i++]);
 658
 659                 fprintf(out_file, "\n");
 660         }
 661
 662         if (dump_contents)
 663                 do_hexdump(out_file, buf, blocksize);
 664
 665 }
 666
 667 static void do_hexdump (FILE *out_file, char *buf, int blocksize)
 668 {
 669         int i,j;
 670         int *intp;
 671         char *charp;
 672         unsigned char c;
 673
 674         intp = (int *) buf;
 675         charp = (char *) buf;
 676
 677         for (i=0; i<blocksize; i+=16) {
 678                 fprintf(out_file, "    %04x:  ", i);
 679                 for (j=0; j<16; j+=4)
 680                         fprintf(out_file, "%08x ", *intp++);
 681                 for (j=0; j<16; j++) {
 682                         c = *charp++;
 683                         if (c < ' ' || c >= 127)
 684                                 c = '.';
 685                         fprintf(out_file, "%c", c);
 686                 }
 687                 fprintf(out_file, "\n");
 688         }
 689 }
 690