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 /* Some constants from POSIX are given names.  */
  27 #define NAME_FIELD_SIZE   100
  28 #define PREFIX_FIELD_SIZE 155
  29 #define UNAME_FIELD_SIZE   32
  30 #define GNAME_FIELD_SIZE   32
  31
  32
  33 \f
  34 /* Some various global definitions.  */
  35
  36 /* Name of file to use for interacting with user.  */
  37
  38 /* GLOBAL is defined to empty in tar.c only, and left alone in other *.c
  39    modules.  Here, we merely set it to "extern" if it is not already set.
  40    GNU tar does depend on the system loader to preset all GLOBAL variables to
  41    neutral (or zero) values, explicit initialization is usually not done.  */
  42 #ifndef GLOBAL
  43 # define GLOBAL extern
  44 #endif
  45
  46 #define TAREXIT_SUCCESS PAXEXIT_SUCCESS
  47 #define TAREXIT_DIFFERS PAXEXIT_DIFFERS
  48 #define TAREXIT_FAILURE PAXEXIT_FAILURE
  49
  50 \f
  51 #include "arith.h"
  52 #include <backupfile.h>
  53 #include <exclude.h>
  54 #include <full-write.h>
  55 #include <modechange.h>
  56 #include <quote.h>
  57 #include <safe-read.h>
  58 #include <stat-time.h>
  59 #include <timespec.h>
  60 #define obstack_chunk_alloc xmalloc
  61 #define obstack_chunk_free free
  62 #include <obstack.h>
  63
  64 #include <paxlib.h>
  65
  66 /* Log base 2 of common values.  */
  67 #define LG_8 3
  68 #define LG_64 6
  69 #define LG_256 8
  70 \f
  71 /* Information gleaned from the command line.  */
  72
  73 /* Name of this program.  */
  74 GLOBAL const char *program_name;
  75
  76 /* Main command option.  */
  77
  78 enum subcommand
  79 {
  80   UNKNOWN_SUBCOMMAND,           /* none of the following */
  81   APPEND_SUBCOMMAND,            /* -r */
  82   CAT_SUBCOMMAND,               /* -A */
  83   CREATE_SUBCOMMAND,            /* -c */
  84   DELETE_SUBCOMMAND,            /* -D */
  85   DIFF_SUBCOMMAND,              /* -d */
  86   EXTRACT_SUBCOMMAND,           /* -x */
  87   LIST_SUBCOMMAND,              /* -t */
  88   UPDATE_SUBCOMMAND             /* -u */
  89 };
  90
  91 GLOBAL enum subcommand subcommand_option;
  92
  93 /* Selected format for output archive.  */
  94 GLOBAL enum archive_format archive_format;
  95
  96 /* Either NL or NUL, as decided by the --null option.  */
  97 GLOBAL char filename_terminator;
  98
  99 /* Size of each record, once in blocks, once in bytes.  Those two variables
 100    are always related, the second being BLOCKSIZE times the first.  They do
 101    not have _option in their name, even if their values is derived from
 102    option decoding, as these are especially important in tar.  */
 103 GLOBAL int blocking_factor;
 104 GLOBAL size_t record_size;
 105
 106 GLOBAL bool absolute_names_option;
 107
 108 /* Display file times in UTC */
 109 GLOBAL bool utc_option;
 110
 111 /* This variable tells how to interpret newer_mtime_option, below.  If zero,
 112    files get archived if their mtime is not less than newer_mtime_option.
 113    If nonzero, files get archived if *either* their ctime or mtime is not less
 114    than newer_mtime_option.  */
 115 GLOBAL int after_date_option;
 116
 117 GLOBAL bool atime_preserve_option;
 118
 119 GLOBAL bool backup_option;
 120
 121 /* Type of backups being made.  */
 122 GLOBAL enum backup_type backup_type;
 123
 124 GLOBAL bool block_number_option;
 125
 126 GLOBAL bool checkpoint_option;
 127
 128 /* Specified name of compression program, or "gzip" as implied by -z.  */
 129 GLOBAL const char *use_compress_program_option;
 130
 131 GLOBAL bool dereference_option;
 132
 133 /* Print a message if not all links are dumped */
 134 GLOBAL int check_links_option;
 135
 136 /* Patterns that match file names to be excluded.  */
 137 GLOBAL struct exclude *excluded;
 138
 139 /* Exclude directories containing a cache directory tag. */
 140 GLOBAL bool exclude_caches_option;
 141
 142 /* Specified value to be put into tar file in place of stat () results, or
 143    just -1 if such an override should not take place.  */
 144 GLOBAL gid_t group_option;
 145
 146 GLOBAL bool ignore_failed_read_option;
 147
 148 GLOBAL bool ignore_zeros_option;
 149
 150 GLOBAL bool incremental_option;
 151
 152 /* Specified name of script to run at end of each tape change.  */
 153 GLOBAL const char *info_script_option;
 154
 155 GLOBAL bool interactive_option;
 156
 157 /* If nonzero, extract only Nth occurrence of each named file */
 158 GLOBAL uintmax_t occurrence_option;
 159
 160 enum old_files
 161 {
 162   DEFAULT_OLD_FILES,          /* default */
 163   NO_OVERWRITE_DIR_OLD_FILES, /* --no-overwrite-dir */
 164   OVERWRITE_OLD_FILES,        /* --overwrite */
 165   UNLINK_FIRST_OLD_FILES,     /* --unlink-first */
 166   KEEP_OLD_FILES,             /* --keep-old-files */
 167   KEEP_NEWER_FILES            /* --keep-newer-files */
 168 };
 169 GLOBAL enum old_files old_files_option;
 170
 171 /* Specified file name for incremental list.  */
 172 GLOBAL const char *listed_incremental_option;
 173
 174 /* Specified mode change string.  */
 175 GLOBAL struct mode_change *mode_option;
 176
 177 /* Initial umask, if needed for mode change string.  */
 178 GLOBAL mode_t initial_umask;
 179
 180 GLOBAL bool multi_volume_option;
 181
 182 /* Specified threshold date and time.  Files having an older time stamp
 183    do not get archived (also see after_date_option above).  */
 184 GLOBAL struct timespec newer_mtime_option;
 185
 186 /* Return true if newer_mtime_option is initialized.  */
 187 #define NEWER_OPTION_INITIALIZED(opt) (0 <= (opt).tv_nsec)
 188
 189 /* Return true if the struct stat ST's M time is less than
 190    newer_mtime_option.  */
 191 #define OLDER_STAT_TIME(st, m) \
 192   (timespec_cmp (get_stat_##m##time (&(st)), newer_mtime_option) < 0)
 193
 194 /* Likewise, for struct tar_stat_info ST.  */
 195 #define OLDER_TAR_STAT_TIME(st, m) \
 196   (timespec_cmp ((st).m##time, newer_mtime_option) < 0)
 197
 198 /* Zero if there is no recursion, otherwise FNM_LEADING_DIR.  */
 199 GLOBAL int recursion_option;
 200
 201 GLOBAL bool numeric_owner_option;
 202
 203 GLOBAL bool one_file_system_option;
 204
 205 /* Specified value to be put into tar file in place of stat () results, or
 206    just -1 if such an override should not take place.  */
 207 GLOBAL uid_t owner_option;
 208
 209 GLOBAL bool recursive_unlink_option;
 210
 211 GLOBAL bool read_full_records_option;
 212
 213 GLOBAL bool remove_files_option;
 214
 215 /* Specified rmt command.  */
 216 GLOBAL const char *rmt_command_option;
 217
 218 /* Specified remote shell command.  */
 219 GLOBAL const char *rsh_command_option;
 220
 221 GLOBAL bool same_order_option;
 222
 223 /* If positive, preserve ownership when extracting.  */
 224 GLOBAL int same_owner_option;
 225
 226 /* If positive, preserve permissions when extracting.  */
 227 GLOBAL int same_permissions_option;
 228
 229 /* When set, strip the given number of file name components from the file name
 230    before extracting */
 231 GLOBAL size_t strip_name_components;
 232
 233 GLOBAL bool show_omitted_dirs_option;
 234
 235 GLOBAL bool sparse_option;
 236
 237 GLOBAL bool starting_file_option;
 238
 239 /* Specified maximum byte length of each tape volume (multiple of 1024).  */
 240 GLOBAL tarlong tape_length_option;
 241
 242 GLOBAL bool to_stdout_option;
 243
 244 GLOBAL bool totals_option;
 245
 246 GLOBAL bool touch_option;
 247
 248 GLOBAL char *to_command_option;
 249 GLOBAL bool ignore_command_error_option;
 250
 251 /* Return true if the extracted files are not being written to disk */
 252 #define EXTRACT_OVER_PIPE (to_stdout_option || to_command_option)
 253
 254 /* Count how many times the option has been set, multiple setting yields
 255    more verbose behavior.  Value 0 means no verbosity, 1 means file name
 256    only, 2 means file name and all attributes.  More than 2 is just like 2.  */
 257 GLOBAL int verbose_option;
 258
 259 GLOBAL bool verify_option;
 260
 261 /* Specified name of file containing the volume number.  */
 262 GLOBAL const char *volno_file_option;
 263
 264 /* Specified value or pattern.  */
 265 GLOBAL const char *volume_label_option;
 266 \f
 267 /* Other global variables.  */
 268
 269 /* File descriptor for archive file.  */
 270 GLOBAL int archive;
 271
 272 /* Nonzero when outputting to /dev/null.  */
 273 GLOBAL bool dev_null_output;
 274
 275 /* Timestamp for when we started execution.  */
 276 GLOBAL struct timespec start_time;
 277
 278 GLOBAL struct tar_stat_info current_stat_info;
 279
 280 /* List of tape drive names, number of such tape drives, allocated number,
 281    and current cursor in list.  */
 282 GLOBAL const char **archive_name_array;
 283 GLOBAL int archive_names;
 284 GLOBAL int allocated_archive_names;
 285 GLOBAL const char **archive_name_cursor;
 286
 287 /* Output index file name.  */
 288 GLOBAL char const *index_file_name;
 289
 290 /* Structure for keeping track of filenames and lists thereof.  */
 291 struct name
 292   {
 293     struct name *next;
 294     size_t length;              /* cached strlen(name) */
 295     uintmax_t found_count;      /* number of times a matching file has
 296                                    been found */
 297     int isdir;
 298     char firstch;               /* first char is literally matched */
 299     char regexp;                /* this name is a regexp, not literal */
 300     int change_dir;             /* set with the -C option */
 301     char const *dir_contents;   /* for incremental_option */
 302     char fake;                  /* dummy entry */
 303     char name[1];
 304   };
 305
 306 /* Obnoxious test to see if dimwit is trying to dump the archive.  */
 307 GLOBAL dev_t ar_dev;
 308 GLOBAL ino_t ar_ino;
 309
 310 GLOBAL bool seekable_archive;
 311
 312 GLOBAL dev_t root_device;
 313
 314 /* Unquote filenames */
 315 GLOBAL bool unquote_option;
 316
 317 GLOBAL bool test_label_option; /* Test archive volume label and exit */
 318
 319 GLOBAL bool show_stored_names_option; /* When creating archive in verbose mode,
 320                                          list member names as stored in the archive */
 321
 322 \f
 323 /* Declarations for each module.  */
 324
 325 /* FIXME: compare.c should not directly handle the following variable,
 326    instead, this should be done in buffer.c only.  */
 327
 328 enum access_mode
 329 {
 330   ACCESS_READ,
 331   ACCESS_WRITE,
 332   ACCESS_UPDATE
 333 };
 334 extern enum access_mode access_mode;
 335
 336 /* Module buffer.c.  */
 337
 338 extern FILE *stdlis;
 339 extern char *save_name;
 340 extern off_t save_sizeleft;
 341 extern off_t save_totsize;
 342 extern bool write_archive_to_stdout;
 343
 344 size_t available_space_after (union block *);
 345 off_t current_block_ordinal (void);
 346 void close_archive (void);
 347 void closeout_volume_number (void);
 348 union block *find_next_block (void);
 349 void flush_read (void);
 350 void flush_write (void);
 351 void flush_archive (void);
 352 void init_volume_number (void);
 353 void open_archive (enum access_mode);
 354 void print_total_written (void);
 355 void reset_eof (void);
 356 void set_next_block_after (union block *);
 357 void clear_read_error_count (void);
 358 void xclose (int fd);
 359 void archive_write_error (ssize_t) __attribute__ ((noreturn));
 360 void archive_read_error (void);
 361 off_t seek_archive (off_t size);
 362 void set_start_time (void);
 363
 364 /* Module create.c.  */
 365
 366 enum dump_status
 367   {
 368     dump_status_ok,
 369     dump_status_short,
 370     dump_status_fail,
 371     dump_status_not_implemented
 372   };
 373
 374 bool file_dumpable_p (struct tar_stat_info *);
 375 void create_archive (void);
 376 void pad_archive (off_t size_left);
 377 void dump_file (char *, int, dev_t);
 378 union block *start_header (struct tar_stat_info *st);
 379 void finish_header (struct tar_stat_info *, union block *, off_t);
 380 void simple_finish_header (union block *header);
 381 union block *start_private_header (const char *name, size_t size);
 382 void write_eot (void);
 383 void check_links (void);
 384
 385 #define GID_TO_CHARS(val, where) gid_to_chars (val, where, sizeof (where))
 386 #define MAJOR_TO_CHARS(val, where) major_to_chars (val, where, sizeof (where))
 387 #define MINOR_TO_CHARS(val, where) minor_to_chars (val, where, sizeof (where))
 388 #define MODE_TO_CHARS(val, where) mode_to_chars (val, where, sizeof (where))
 389 #define OFF_TO_CHARS(val, where) off_to_chars (val, where, sizeof (where))
 390 #define SIZE_TO_CHARS(val, where) size_to_chars (val, where, sizeof (where))
 391 #define TIME_TO_CHARS(val, where) time_to_chars (val, where, sizeof (where))
 392 #define UID_TO_CHARS(val, where) uid_to_chars (val, where, sizeof (where))
 393 #define UINTMAX_TO_CHARS(val, where) uintmax_to_chars (val, where, sizeof (where))
 394 #define UNAME_TO_CHARS(name,buf) string_to_chars (name, buf, sizeof(buf))
 395 #define GNAME_TO_CHARS(name,buf) string_to_chars (name, buf, sizeof(buf))
 396
 397 void gid_to_chars (gid_t, char *, size_t);
 398 void major_to_chars (major_t, char *, size_t);
 399 void minor_to_chars (minor_t, char *, size_t);
 400 void mode_to_chars (mode_t, char *, size_t);
 401 void off_to_chars (off_t, char *, size_t);
 402 void size_to_chars (size_t, char *, size_t);
 403 void time_to_chars (time_t, char *, size_t);
 404 void uid_to_chars (uid_t, char *, size_t);
 405 void uintmax_to_chars (uintmax_t, char *, size_t);
 406 void string_to_chars (char const *, char *, size_t);
 407
 408 /* Module diffarch.c.  */
 409
 410 extern bool now_verifying;
 411
 412 void diff_archive (void);
 413 void diff_init (void);
 414 void verify_volume (void);
 415
 416 /* Module extract.c.  */
 417
 418 void extr_init (void);
 419 void extract_archive (void);
 420 void extract_finish (void);
 421
 422 /* Module delete.c.  */
 423
 424 void delete_archive_members (void);
 425
 426 /* Module incremen.c.  */
 427
 428 char *get_directory_contents (char *, dev_t);
 429 void read_directory_file (void);
 430 void write_directory_file (void);
 431 void purge_directory (char const *);
 432 void list_dumpdir (char *buffer, size_t size);
 433 void update_parent_directory (const char *name);
 434
 435 /* Module list.c.  */
 436
 437 enum read_header
 438 {
 439   HEADER_STILL_UNREAD,          /* for when read_header has not been called */
 440   HEADER_SUCCESS,               /* header successfully read and checksummed */
 441   HEADER_SUCCESS_EXTENDED,      /* likewise, but we got an extended header */
 442   HEADER_ZERO_BLOCK,            /* zero block where header expected */
 443   HEADER_END_OF_FILE,           /* true end of file while header expected */
 444   HEADER_FAILURE                /* ill-formed header, or bad checksum */
 445 };
 446
 447 struct xheader
 448 {
 449   struct obstack *stk;
 450   size_t size;
 451   char *buffer;
 452 };
 453
 454 GLOBAL struct xheader extended_header;
 455 extern union block *current_header;
 456 extern enum archive_format current_format;
 457 extern size_t recent_long_name_blocks;
 458 extern size_t recent_long_link_blocks;
 459
 460 void decode_header (union block *, struct tar_stat_info *,
 461                     enum archive_format *, int);
 462 char const *tartime (struct timespec, bool);
 463
 464 #define GID_FROM_HEADER(where) gid_from_header (where, sizeof (where))
 465 #define MAJOR_FROM_HEADER(where) major_from_header (where, sizeof (where))
 466 #define MINOR_FROM_HEADER(where) minor_from_header (where, sizeof (where))
 467 #define MODE_FROM_HEADER(where) mode_from_header (where, sizeof (where))
 468 #define OFF_FROM_HEADER(where) off_from_header (where, sizeof (where))
 469 #define SIZE_FROM_HEADER(where) size_from_header (where, sizeof (where))
 470 #define TIME_FROM_HEADER(where) time_from_header (where, sizeof (where))
 471 #define UID_FROM_HEADER(where) uid_from_header (where, sizeof (where))
 472 #define UINTMAX_FROM_HEADER(where) uintmax_from_header (where, sizeof (where))
 473
 474 gid_t gid_from_header (const char *, size_t);
 475 major_t major_from_header (const char *, size_t);
 476 minor_t minor_from_header (const char *, size_t);
 477 mode_t mode_from_header (const char *, size_t);
 478 off_t off_from_header (const char *, size_t);
 479 size_t size_from_header (const char *, size_t);
 480 time_t time_from_header (const char *, size_t);
 481 uid_t uid_from_header (const char *, size_t);
 482 uintmax_t uintmax_from_header (const char *, size_t);
 483
 484 void list_archive (void);
 485 void print_for_mkdir (char *, int, mode_t);
 486 void print_header (struct tar_stat_info *, off_t);
 487 void read_and (void (*) (void));
 488 enum read_header read_header (bool);
 489 enum read_header tar_checksum (union block *header, bool silent);
 490 void skip_file (off_t);
 491 void skip_member (void);
 492
 493 /* Module mangle.c.  */
 494
 495 void extract_mangle (void);
 496
 497 /* Module misc.c.  */
 498
 499 void assign_string (char **, const char *);
 500 char *quote_copy_string (const char *);
 501 int unquote_string (char *);
 502
 503 void code_ns_fraction (int, char *);
 504 char const *code_timespec (struct timespec, char *);
 505 enum { BILLION = 1000000000, LOG10_BILLION = 9 };
 506 enum { TIMESPEC_STRSIZE_BOUND =
 507          UINTMAX_STRSIZE_BOUND + LOG10_BILLION + sizeof "-." - 1 };
 508
 509 size_t dot_dot_prefix_len (char const *);
 510
 511 enum remove_option
 512 {
 513   ORDINARY_REMOVE_OPTION,
 514   RECURSIVE_REMOVE_OPTION,
 515
 516   /* FIXME: The following value is never used. It seems to be intended
 517      as a placeholder for a hypothetical option that should instruct tar
 518      to recursively remove subdirectories in purge_directory(),
 519      as opposed to the functionality of --recursive-unlink
 520      (RECURSIVE_REMOVE_OPTION value), which removes them in
 521      prepare_to_extract() phase. However, with the addition of more
 522      meta-info to the incremental dumps, this should become unnecessary */
 523   WANT_DIRECTORY_REMOVE_OPTION
 524 };
 525 int remove_any_file (const char *, enum remove_option);
 526 bool maybe_backup_file (const char *, int);
 527 void undo_last_backup (void);
 528
 529 int deref_stat (bool, char const *, struct stat *);
 530
 531 int chdir_arg (char const *);
 532 void chdir_do (int);
 533
 534 void close_diag (char const *name);
 535 void open_diag (char const *name);
 536 void read_diag_details (char const *name, off_t offset, size_t size);
 537 void readlink_diag (char const *name);
 538 void savedir_diag (char const *name);
 539 void seek_diag_details (char const *, off_t);
 540 void stat_diag (char const *name);
 541 void write_error_details (char const *, size_t, size_t);
 542 void write_fatal (char const *) __attribute__ ((noreturn));
 543 void write_fatal_details (char const *, ssize_t, size_t)
 544      __attribute__ ((noreturn));
 545
 546 pid_t xfork (void);
 547 void xpipe (int[2]);
 548
 549 void *page_aligned_alloc (void **, size_t);
 550
 551 /* Module names.c.  */
 552
 553 extern struct name *gnu_list_name;
 554
 555 void gid_to_gname (gid_t, char **gname);
 556 int gname_to_gid (char const *, gid_t *);
 557 void uid_to_uname (uid_t, char **uname);
 558 int uname_to_uid (char const *, uid_t *);
 559
 560 void init_names (void);
 561 void name_add (const char *);
 562 void name_init (void);
 563 void name_term (void);
 564 char *name_next (int);
 565 void name_gather (void);
 566 struct name *addname (char const *, int);
 567 int name_match (const char *);
 568 void names_notfound (void);
 569 void collect_and_sort_names (void);
 570 struct name *name_scan (const char *);
 571 char *name_from_list (void);
 572 void blank_name_list (void);
 573 char *new_name (const char *, const char *);
 574 size_t stripped_prefix_len (char const *file_name, size_t num);
 575 bool all_names_found (struct tar_stat_info *);
 576
 577 bool excluded_name (char const *);
 578
 579 void add_avoided_name (char const *);
 580 bool is_avoided_name (char const *);
 581 bool is_individual_file (char const *);
 582
 583 bool contains_dot_dot (char const *);
 584
 585 #define ISFOUND(c) ((occurrence_option == 0) ? (c)->found_count : \
 586                     (c)->found_count == occurrence_option)
 587 #define WASFOUND(c) ((occurrence_option == 0) ? (c)->found_count : \
 588                      (c)->found_count >= occurrence_option)
 589
 590 /* Module tar.c.  */
 591
 592 void usage (int);
 593
 594 int confirm (const char *, const char *);
 595 void request_stdin (const char *);
 596
 597 void tar_stat_init (struct tar_stat_info *st);
 598 void tar_stat_destroy (struct tar_stat_info *st);
 599 void usage (int) __attribute__ ((noreturn));
 600
 601 /* Module update.c.  */
 602
 603 extern char *output_start;
 604
 605 void update_archive (void);
 606
 607 /* Module xheader.c.  */
 608
 609 void xheader_decode (struct tar_stat_info *);
 610 void xheader_decode_global (void);
 611 void xheader_store (char const *, struct tar_stat_info const *, void *);
 612 void xheader_read (union block *, size_t);
 613 void xheader_write (char type, char *name, struct xheader *xhdr);
 614 void xheader_write_global (void);
 615 void xheader_finish (struct xheader *);
 616 void xheader_destroy (struct xheader *);
 617 char *xheader_xhdr_name (struct tar_stat_info *st);
 618 char *xheader_ghdr_name (void);
 619 void xheader_write (char, char *, struct xheader *);
 620 void xheader_write_global (void);
 621 void xheader_set_option (char *string);
 622
 623 /* Module system.c */
 624
 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);