Dogcows Code - chaz/tar/blob - src/common.h

   1 /* Common declarations for the tar program.
   2
   3    Copyright (C) 1988, 1992, 1993, 1994, 1996, 1997, 1999, 2000, 2001,
   4    2003, 2004, 2005 Free Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published by the
   8    Free Software Foundation; either version 2, or (at your option) any later
   9    version.
  10
  11    This program is distributed in the hope that it will be useful, but
  12    WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
  14    Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License along
  17    with this program; if not, write to the Free Software Foundation, Inc.,
  18    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  19
  20 /* Declare the GNU tar archive format.  */
  21 #include "tar.h"
  22
  23 /* The checksum field is filled with this while the checksum is computed.  */
  24 #define CHKBLANKS       "        "      /* 8 blanks, no null */
  25
  26 /* Old GNU stores zero-terminated file name */
  27 #define OLDGNU_NAME_FIELD_SIZE   99
  28
  29 /* Some constants from POSIX are given names.  */
  30 #define NAME_FIELD_SIZE   100
  31 #define PREFIX_FIELD_SIZE 155
  32 #define UNAME_FIELD_SIZE   32
  33 #define GNAME_FIELD_SIZE   32
  34
  35 /* FIXME */
  36 #define MAXOCTAL11      017777777777L
  37 #define MAXOCTAL7       07777777
  38
  39
  40 \f
  41 /* Some various global definitions.  */
  42
  43 /* Name of file to use for interacting with user.  */
  44
  45 /* GLOBAL is defined to empty in tar.c only, and left alone in other *.c
  46    modules.  Here, we merely set it to "extern" if it is not already set.
  47    GNU tar does depend on the system loader to preset all GLOBAL variables to
  48    neutral (or zero) values, explicit initialization is usually not done.  */
  49 #ifndef GLOBAL
  50 # define GLOBAL extern
  51 #endif
  52
  53 #define TAREXIT_SUCCESS PAXEXIT_SUCCESS
  54 #define TAREXIT_DIFFERS PAXEXIT_DIFFERS
  55 #define TAREXIT_FAILURE PAXEXIT_FAILURE
  56
  57 \f
  58 #include "arith.h"
  59 #include <backupfile.h>
  60 #include <exclude.h>
  61 #include <full-write.h>
  62 #include <modechange.h>
  63 #include <quote.h>
  64 #include <safe-read.h>
  65 #include <timespec.h>
  66 #define obstack_chunk_alloc xmalloc
  67 #define obstack_chunk_free free
  68 #include <obstack.h>
  69
  70 #include <paxlib.h>
  71
  72 /* Log base 2 of common values.  */
  73 #define LG_8 3
  74 #define LG_64 6
  75 #define LG_256 8
  76 \f
  77 /* Information gleaned from the command line.  */
  78
  79 /* Name of this program.  */
  80 GLOBAL const char *program_name;
  81
  82 /* Main command option.  */
  83
  84 enum subcommand
  85 {
  86   UNKNOWN_SUBCOMMAND,           /* none of the following */
  87   APPEND_SUBCOMMAND,            /* -r */
  88   CAT_SUBCOMMAND,               /* -A */
  89   CREATE_SUBCOMMAND,            /* -c */
  90   DELETE_SUBCOMMAND,            /* -D */
  91   DIFF_SUBCOMMAND,              /* -d */
  92   EXTRACT_SUBCOMMAND,           /* -x */
  93   LIST_SUBCOMMAND,              /* -t */
  94   UPDATE_SUBCOMMAND             /* -u */
  95 };
  96
  97 GLOBAL enum subcommand subcommand_option;
  98
  99 /* Selected format for output archive.  */
 100 GLOBAL enum archive_format archive_format;
 101
 102 /* Either NL or NUL, as decided by the --null option.  */
 103 GLOBAL char filename_terminator;
 104
 105 /* Size of each record, once in blocks, once in bytes.  Those two variables
 106    are always related, the second being BLOCKSIZE times the first.  They do
 107    not have _option in their name, even if their values is derived from
 108    option decoding, as these are especially important in tar.  */
 109 GLOBAL int blocking_factor;
 110 GLOBAL size_t record_size;
 111
 112 GLOBAL bool absolute_names_option;
 113
 114 /* Display file times in UTC */
 115 GLOBAL bool utc_option;
 116
 117 /* This variable tells how to interpret newer_mtime_option, below.  If zero,
 118    files get archived if their mtime is not less than newer_mtime_option.
 119    If nonzero, files get archived if *either* their ctime or mtime is not less
 120    than newer_mtime_option.  */
 121 GLOBAL int after_date_option;
 122
 123 GLOBAL bool atime_preserve_option;
 124
 125 GLOBAL bool backup_option;
 126
 127 /* Type of backups being made.  */
 128 GLOBAL enum backup_type backup_type;
 129
 130 GLOBAL bool block_number_option;
 131
 132 GLOBAL bool checkpoint_option;
 133
 134 /* Specified name of compression program, or "gzip" as implied by -z.  */
 135 GLOBAL const char *use_compress_program_option;
 136
 137 GLOBAL bool dereference_option;
 138
 139 /* Print a message if not all links are dumped */
 140 GLOBAL int check_links_option;
 141
 142 /* Patterns that match file names to be excluded.  */
 143 GLOBAL struct exclude *excluded;
 144
 145 /* Exclude directories containing a cache directory tag. */
 146 GLOBAL bool exclude_caches_option;
 147
 148 /* Specified value to be put into tar file in place of stat () results, or
 149    just -1 if such an override should not take place.  */
 150 GLOBAL gid_t group_option;
 151
 152 GLOBAL bool ignore_failed_read_option;
 153
 154 GLOBAL bool ignore_zeros_option;
 155
 156 GLOBAL bool incremental_option;
 157
 158 /* Specified name of script to run at end of each tape change.  */
 159 GLOBAL const char *info_script_option;
 160
 161 GLOBAL bool interactive_option;
 162
 163 /* If nonzero, extract only Nth occurrence of each named file */
 164 GLOBAL uintmax_t occurrence_option;
 165
 166 enum old_files
 167 {
 168   DEFAULT_OLD_FILES,          /* default */
 169   NO_OVERWRITE_DIR_OLD_FILES, /* --no-overwrite-dir */
 170   OVERWRITE_OLD_FILES,        /* --overwrite */
 171   UNLINK_FIRST_OLD_FILES,     /* --unlink-first */
 172   KEEP_OLD_FILES,             /* --keep-old-files */
 173   KEEP_NEWER_FILES            /* --keep-newer-files */
 174 };
 175 GLOBAL enum old_files old_files_option;
 176
 177 /* Specified file name for incremental list.  */
 178 GLOBAL const char *listed_incremental_option;
 179
 180 /* Specified mode change string.  */
 181 GLOBAL struct mode_change *mode_option;
 182
 183 /* Initial umask, if needed for mode change string.  */
 184 GLOBAL mode_t initial_umask;
 185
 186 GLOBAL bool multi_volume_option;
 187
 188 /* The same variable holds the time, whether mtime or ctime.  Just fake a
 189    non-existing option, for making the code clearer, elsewhere.  */
 190 #define newer_ctime_option newer_mtime_option
 191
 192 /* Specified threshold date and time.  Files having an older time stamp
 193    do not get archived (also see after_date_option above).  */
 194 GLOBAL struct timespec newer_mtime_option;
 195
 196 /* Return true if newer_mtime_option is initialized.  */
 197 #define NEWER_OPTION_INITIALIZED(opt) (0 <= (opt).tv_nsec)
 198
 199 /* Return true if the struct stat ST's M time is less than
 200    newer_mtime_option.  */
 201 #define OLDER_STAT_TIME(st, m) \
 202   ((st).st_##m##time < newer_mtime_option.tv_sec \
 203    || ((st).st_##m##time == newer_mtime_option.tv_sec \
 204        && TIMESPEC_NS ((st).st_##m##tim) < newer_mtime_option.tv_nsec))
 205
 206 /* Zero if there is no recursion, otherwise FNM_LEADING_DIR.  */
 207 GLOBAL int recursion_option;
 208
 209 GLOBAL bool numeric_owner_option;
 210
 211 GLOBAL bool one_file_system_option;
 212
 213 /* Specified value to be put into tar file in place of stat () results, or
 214    just -1 if such an override should not take place.  */
 215 GLOBAL uid_t owner_option;
 216
 217 GLOBAL bool recursive_unlink_option;
 218
 219 GLOBAL bool read_full_records_option;
 220
 221 GLOBAL bool remove_files_option;
 222
 223 /* Specified rmt command.  */
 224 GLOBAL const char *rmt_command_option;
 225
 226 /* Specified remote shell command.  */
 227 GLOBAL const char *rsh_command_option;
 228
 229 GLOBAL bool same_order_option;
 230
 231 /* If positive, preserve ownership when extracting.  */
 232 GLOBAL int same_owner_option;
 233
 234 /* If positive, preserve permissions when extracting.  */
 235 GLOBAL int same_permissions_option;
 236
 237 /* When set, strip the given number of file name components from the file name
 238    before extracting */
 239 GLOBAL size_t strip_name_components;
 240
 241 GLOBAL bool show_omitted_dirs_option;
 242
 243 GLOBAL bool sparse_option;
 244
 245 GLOBAL bool starting_file_option;
 246
 247 /* Specified maximum byte length of each tape volume (multiple of 1024).  */
 248 GLOBAL tarlong tape_length_option;
 249
 250 GLOBAL bool to_stdout_option;
 251
 252 GLOBAL bool totals_option;
 253
 254 GLOBAL bool touch_option;
 255
 256 GLOBAL char *to_command_option;
 257 GLOBAL bool ignore_command_error_option;
 258
 259 /* Return true if the extracted files are not being written to disk */
 260 #define EXTRACT_OVER_PIPE (to_stdout_option || to_command_option)
 261
 262 /* Count how many times the option has been set, multiple setting yields
 263    more verbose behavior.  Value 0 means no verbosity, 1 means file name
 264    only, 2 means file name and all attributes.  More than 2 is just like 2.  */
 265 GLOBAL int verbose_option;
 266
 267 GLOBAL bool verify_option;
 268
 269 /* Specified name of file containing the volume number.  */
 270 GLOBAL const char *volno_file_option;
 271
 272 /* Specified value or pattern.  */
 273 GLOBAL const char *volume_label_option;
 274 \f
 275 /* Other global variables.  */
 276
 277 /* File descriptor for archive file.  */
 278 GLOBAL int archive;
 279
 280 /* Nonzero when outputting to /dev/null.  */
 281 GLOBAL bool dev_null_output;
 282
 283 /* Timestamp for when we started execution.  */
 284 #if HAVE_CLOCK_GETTIME
 285   GLOBAL struct timespec start_timespec;
 286 # define start_time (start_timespec.tv_sec)
 287 #else
 288   GLOBAL time_t start_time;
 289 #endif
 290
 291 GLOBAL struct tar_stat_info current_stat_info;
 292
 293 /* List of tape drive names, number of such tape drives, allocated number,
 294    and current cursor in list.  */
 295 GLOBAL const char **archive_name_array;
 296 GLOBAL int archive_names;
 297 GLOBAL int allocated_archive_names;
 298 GLOBAL const char **archive_name_cursor;
 299
 300 /* Output index file name.  */
 301 GLOBAL char const *index_file_name;
 302
 303 /* Structure for keeping track of filenames and lists thereof.  */
 304 struct name
 305   {
 306     struct name *next;
 307     size_t length;              /* cached strlen(name) */
 308     uintmax_t found_count;      /* number of times a matching file has
 309                                    been found */
 310     int isdir;
 311     char firstch;               /* first char is literally matched */
 312     char regexp;                /* this name is a regexp, not literal */
 313     int change_dir;             /* set with the -C option */
 314     char const *dir_contents;   /* for incremental_option */
 315     char fake;                  /* dummy entry */
 316     char name[1];
 317   };
 318
 319 /* Obnoxious test to see if dimwit is trying to dump the archive.  */
 320 GLOBAL dev_t ar_dev;
 321 GLOBAL ino_t ar_ino;
 322
 323 GLOBAL bool seekable_archive;
 324
 325 GLOBAL dev_t root_device;
 326
 327 /* Unquote filenames */
 328 GLOBAL bool unquote_option;
 329 \f
 330 /* Declarations for each module.  */
 331
 332 /* FIXME: compare.c should not directly handle the following variable,
 333    instead, this should be done in buffer.c only.  */
 334
 335 enum access_mode
 336 {
 337   ACCESS_READ,
 338   ACCESS_WRITE,
 339   ACCESS_UPDATE
 340 };
 341 extern enum access_mode access_mode;
 342
 343 /* Module buffer.c.  */
 344
 345 extern FILE *stdlis;
 346 extern char *save_name;
 347 extern off_t save_sizeleft;
 348 extern off_t save_totsize;
 349 extern bool write_archive_to_stdout;
 350
 351 size_t available_space_after (union block *);
 352 off_t current_block_ordinal (void);
 353 void close_archive (void);
 354 void closeout_volume_number (void);
 355 union block *find_next_block (void);
 356 void flush_read (void);
 357 void flush_write (void);
 358 void flush_archive (void);
 359 void init_volume_number (void);
 360 void open_archive (enum access_mode);
 361 void print_total_written (void);
 362 void reset_eof (void);
 363 void set_next_block_after (union block *);
 364 void clear_read_error_count (void);
 365 void xclose (int fd);
 366 void archive_write_error (ssize_t) __attribute__ ((noreturn));
 367 void archive_read_error (void);
 368 off_t seek_archive (off_t size);
 369 void set_start_time (void);
 370
 371 /* Module create.c.  */
 372
 373 enum dump_status
 374   {
 375     dump_status_ok,
 376     dump_status_short,
 377     dump_status_fail,
 378     dump_status_not_implemented
 379   };
 380
 381 bool file_dumpable_p (struct tar_stat_info *);
 382 void create_archive (void);
 383 void pad_archive (off_t size_left);
 384 void dump_file (char *, int, dev_t);
 385 union block *start_header (struct tar_stat_info *st);
 386 void finish_header (struct tar_stat_info *, union block *, off_t);
 387 void simple_finish_header (union block *header);
 388 union block *start_private_header (const char *name, size_t size);
 389 void write_eot (void);
 390 void check_links (void);
 391
 392 #define GID_TO_CHARS(val, where) gid_to_chars (val, where, sizeof (where))
 393 #define MAJOR_TO_CHARS(val, where) major_to_chars (val, where, sizeof (where))
 394 #define MINOR_TO_CHARS(val, where) minor_to_chars (val, where, sizeof (where))
 395 #define MODE_TO_CHARS(val, where) mode_to_chars (val, where, sizeof (where))
 396 #define OFF_TO_CHARS(val, where) off_to_chars (val, where, sizeof (where))
 397 #define SIZE_TO_CHARS(val, where) size_to_chars (val, where, sizeof (where))
 398 #define TIME_TO_CHARS(val, where) time_to_chars (val, where, sizeof (where))
 399 #define UID_TO_CHARS(val, where) uid_to_chars (val, where, sizeof (where))
 400 #define UINTMAX_TO_CHARS(val, where) uintmax_to_chars (val, where, sizeof (where))
 401 #define UNAME_TO_CHARS(name,buf) string_to_chars (name, buf, sizeof(buf))
 402 #define GNAME_TO_CHARS(name,buf) string_to_chars (name, buf, sizeof(buf))
 403
 404 void gid_to_chars (gid_t, char *, size_t);
 405 void major_to_chars (major_t, char *, size_t);
 406 void minor_to_chars (minor_t, char *, size_t);
 407 void mode_to_chars (mode_t, char *, size_t);
 408 void off_to_chars (off_t, char *, size_t);
 409 void size_to_chars (size_t, char *, size_t);
 410 void time_to_chars (time_t, char *, size_t);
 411 void uid_to_chars (uid_t, char *, size_t);
 412 void uintmax_to_chars (uintmax_t, char *, size_t);
 413 void string_to_chars (char *, char *, size_t);
 414
 415 /* Module diffarch.c.  */
 416
 417 extern bool now_verifying;
 418
 419 void diff_archive (void);
 420 void diff_init (void);
 421 void verify_volume (void);
 422
 423 /* Module extract.c.  */
 424
 425 void extr_init (void);
 426 void extract_archive (void);
 427 void extract_finish (void);
 428
 429 /* Module delete.c.  */
 430
 431 void delete_archive_members (void);
 432
 433 /* Module incremen.c.  */
 434
 435 char *get_directory_contents (char *, dev_t);
 436 void read_directory_file (void);
 437 void write_directory_file (void);
 438 void purge_directory (char const *);
 439
 440 /* Module list.c.  */
 441
 442 enum read_header
 443 {
 444   HEADER_STILL_UNREAD,          /* for when read_header has not been called */
 445   HEADER_SUCCESS,               /* header successfully read and checksummed */
 446   HEADER_SUCCESS_EXTENDED,      /* likewise, but we got an extended header */
 447   HEADER_ZERO_BLOCK,            /* zero block where header expected */
 448   HEADER_END_OF_FILE,           /* true end of file while header expected */
 449   HEADER_FAILURE                /* ill-formed header, or bad checksum */
 450 };
 451
 452 struct xheader
 453 {
 454   struct obstack *stk;
 455   size_t size;
 456   char *buffer;
 457 };
 458
 459 GLOBAL struct xheader extended_header;
 460 extern union block *current_header;
 461 extern enum archive_format current_format;
 462 extern size_t recent_long_name_blocks;
 463 extern size_t recent_long_link_blocks;
 464
 465 void decode_header (union block *, struct tar_stat_info *,
 466                     enum archive_format *, int);
 467 char const *tartime (time_t);
 468
 469 #define GID_FROM_HEADER(where) gid_from_header (where, sizeof (where))
 470 #define MAJOR_FROM_HEADER(where) major_from_header (where, sizeof (where))
 471 #define MINOR_FROM_HEADER(where) minor_from_header (where, sizeof (where))
 472 #define MODE_FROM_HEADER(where) mode_from_header (where, sizeof (where))
 473 #define OFF_FROM_HEADER(where) off_from_header (where, sizeof (where))
 474 #define SIZE_FROM_HEADER(where) size_from_header (where, sizeof (where))
 475 #define TIME_FROM_HEADER(where) time_from_header (where, sizeof (where))
 476 #define UID_FROM_HEADER(where) uid_from_header (where, sizeof (where))
 477 #define UINTMAX_FROM_HEADER(where) uintmax_from_header (where, sizeof (where))
 478
 479 gid_t gid_from_header (const char *, size_t);
 480 major_t major_from_header (const char *, size_t);
 481 minor_t minor_from_header (const char *, size_t);
 482 mode_t mode_from_header (const char *, size_t);
 483 off_t off_from_header (const char *, size_t);
 484 size_t size_from_header (const char *, size_t);
 485 time_t time_from_header (const char *, size_t);
 486 uid_t uid_from_header (const char *, size_t);
 487 uintmax_t uintmax_from_header (const char *, size_t);
 488
 489 void list_archive (void);
 490 void print_for_mkdir (char *, int, mode_t);
 491 void print_header (struct tar_stat_info *, off_t);
 492 void read_and (void (*) (void));
 493 enum read_header read_header (bool);
 494 enum read_header tar_checksum (union block *header, bool silent);
 495 void skip_file (off_t);
 496 void skip_member (void);
 497
 498 /* Module mangle.c.  */
 499
 500 void extract_mangle (void);
 501
 502 /* Module misc.c.  */
 503
 504 void assign_string (char **, const char *);
 505 char *quote_copy_string (const char *);
 506 int unquote_string (char *);
 507
 508 size_t dot_dot_prefix_len (char const *);
 509
 510 enum remove_option
 511 {
 512   ORDINARY_REMOVE_OPTION,
 513   RECURSIVE_REMOVE_OPTION,
 514
 515   /* FIXME: The following value is never used. It seems to be intended
 516      as a placeholder for a hypothetical option that should instruct tar
 517      to recursively remove subdirectories in purge_directory(),
 518      as opposed to the functionality of --recursive-unlink
 519      (RECURSIVE_REMOVE_OPTION value), which removes them in
 520      prepare_to_extract() phase. However, with the addition of more
 521      meta-info to the incremental dumps, this should become unnecessary */
 522   WANT_DIRECTORY_REMOVE_OPTION
 523 };
 524 int remove_any_file (const char *, enum remove_option);
 525 bool maybe_backup_file (const char *, int);
 526 void undo_last_backup (void);
 527
 528 int deref_stat (bool, char const *, struct stat *);
 529
 530 int chdir_arg (char const *);
 531 void chdir_do (int);
 532
 533 void close_diag (char const *name);
 534 void open_diag (char const *name);
 535 void read_diag_details (char const *name, off_t offset, size_t size);
 536 void readlink_diag (char const *name);
 537 void savedir_diag (char const *name);
 538 void seek_diag_details (char const *, off_t);
 539 void stat_diag (char const *name);
 540 void write_error_details (char const *, size_t, size_t);
 541 void write_fatal (char const *) __attribute__ ((noreturn));
 542 void write_fatal_details (char const *, ssize_t, size_t)
 543      __attribute__ ((noreturn));
 544
 545 pid_t xfork (void);
 546 void xpipe (int[2]);
 547
 548 void *page_aligned_alloc (void **, size_t);
 549
 550 /* Module names.c.  */
 551
 552 extern struct name *gnu_list_name;
 553
 554 void gid_to_gname (gid_t, char **gname);
 555 int gname_to_gid (char const *, gid_t *);
 556 void uid_to_uname (uid_t, char **uname);
 557 int uname_to_uid (char const *, uid_t *);
 558
 559 void init_names (void);
 560 void name_add (const char *);
 561 void name_init (void);
 562 void name_term (void);
 563 char *name_next (int);
 564 void name_gather (void);
 565 struct name *addname (char const *, int);
 566 int name_match (const char *);
 567 void names_notfound (void);
 568 void collect_and_sort_names (void);
 569 struct name *name_scan (const char *);
 570 char *name_from_list (void);
 571 void blank_name_list (void);
 572 char *new_name (const char *, const char *);
 573 size_t stripped_prefix_len (char const *file_name, size_t num);
 574 bool all_names_found (struct tar_stat_info *);
 575
 576 bool excluded_name (char const *);
 577
 578 void add_avoided_name (char const *);
 579 bool is_avoided_name (char const *);
 580 bool is_individual_file (char const *);
 581
 582 bool contains_dot_dot (char const *);
 583
 584 #define ISFOUND(c) ((occurrence_option == 0) ? (c)->found_count : \
 585                     (c)->found_count == occurrence_option)
 586 #define WASFOUND(c) ((occurrence_option == 0) ? (c)->found_count : \
 587                      (c)->found_count >= occurrence_option)
 588
 589 /* Module tar.c.  */
 590
 591 void usage (int);
 592
 593 int confirm (const char *, const char *);
 594 void request_stdin (const char *);
 595
 596 void tar_stat_init (struct tar_stat_info *st);
 597 void tar_stat_destroy (struct tar_stat_info *st);
 598 void usage (int) __attribute__ ((noreturn));
 599
 600 /* Module update.c.  */
 601
 602 extern char *output_start;
 603
 604 void update_archive (void);
 605
 606 /* Module xheader.c.  */
 607
 608 void xheader_decode (struct tar_stat_info *);
 609 void xheader_decode_global (void);
 610 void xheader_store (char const *, struct tar_stat_info const *, void *);
 611 void xheader_read (union block *, size_t);
 612 void xheader_write (char type, char *name, struct xheader *xhdr);
 613 void xheader_write_global (void);
 614 void xheader_finish (struct xheader *);
 615 void xheader_destroy (struct xheader *);
 616 char *xheader_xhdr_name (struct tar_stat_info *st);
 617 char *xheader_ghdr_name (void);
 618 void xheader_write (char, char *, struct xheader *);
 619 void xheader_write_global (void);
 620 void xheader_set_option (char *string);
 621
 622 /* Module system.c */
 623
 624 void sys_stat_nanoseconds (struct tar_stat_info *);
 625 void sys_detect_dev_null_output (void);
 626 void sys_save_archive_dev_ino (void);
 627 void sys_drain_input_pipe (void);
 628 void sys_wait_for_child (pid_t);
 629 void sys_spawn_shell (void);
 630 bool sys_compare_uid (struct stat *a, struct stat *b);
 631 bool sys_compare_gid (struct stat *a, struct stat *b);
 632 bool sys_file_is_archive (struct tar_stat_info *p);
 633 bool sys_compare_links (struct stat *link_data, struct stat *stat_data);
 634 int sys_truncate (int fd);
 635 pid_t sys_child_open_for_compress (void);
 636 pid_t sys_child_open_for_uncompress (void);
 637 size_t sys_write_archive_buffer (void);
 638 bool sys_get_archive_stat (void);
 639 int sys_exec_command (char *file_name, int typechar, struct tar_stat_info *st);
 640 void sys_wait_command (void);
 641
 642 /* Module compare.c */
 643 void report_difference (struct tar_stat_info *st, const char *message, ...);
 644
 645 /* Module sparse.c */
 646 bool sparse_file_p (struct tar_stat_info *);
 647 bool sparse_member_p (struct tar_stat_info *);
 648 bool sparse_fixup_header (struct tar_stat_info *);
 649 enum dump_status sparse_dump_file (int, struct tar_stat_info *);
 650 enum dump_status sparse_extract_file (int, struct tar_stat_info *, off_t *);
 651 enum dump_status sparse_skip_file (struct tar_stat_info *);
 652 bool sparse_diff_file (int, struct tar_stat_info *);
 653
 654 /* Module utf8.c */
 655 bool string_ascii_p (const char *str);
 656 bool utf8_convert (bool to_utf, char const *input, char **output);