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 enum atime_preserve
 118 {
 119   no_atime_preserve,
 120   replace_atime_preserve,
 121   system_atime_preserve
 122 };
 123 GLOBAL enum atime_preserve 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 /* Specified threshold date and time.  Files having an older time stamp
 189    do not get archived (also see after_date_option above).  */
 190 GLOBAL struct timespec newer_mtime_option;
 191
 192 /* Return true if newer_mtime_option is initialized.  */
 193 #define NEWER_OPTION_INITIALIZED(opt) (0 <= (opt).tv_nsec)
 194
 195 /* Return true if the struct stat ST's M time is less than
 196    newer_mtime_option.  */
 197 #define OLDER_STAT_TIME(st, m) \
 198   (timespec_cmp (get_stat_##m##time (&(st)), newer_mtime_option) < 0)
 199
 200 /* Likewise, for struct tar_stat_info ST.  */
 201 #define OLDER_TAR_STAT_TIME(st, m) \
 202   (timespec_cmp ((st).m##time, newer_mtime_option) < 0)
 203
 204 /* Zero if there is no recursion, otherwise FNM_LEADING_DIR.  */
 205 GLOBAL int recursion_option;
 206
 207 GLOBAL bool numeric_owner_option;
 208
 209 GLOBAL bool one_file_system_option;
 210
 211 /* Specified value to be put into tar file in place of stat () results, or
 212    just -1 if such an override should not take place.  */
 213 GLOBAL uid_t owner_option;
 214
 215 GLOBAL bool recursive_unlink_option;
 216
 217 GLOBAL bool read_full_records_option;
 218
 219 GLOBAL bool remove_files_option;
 220
 221 /* Specified rmt command.  */
 222 GLOBAL const char *rmt_command_option;
 223
 224 /* Specified remote shell command.  */
 225 GLOBAL const char *rsh_command_option;
 226
 227 GLOBAL bool same_order_option;
 228
 229 /* If positive, preserve ownership when extracting.  */
 230 GLOBAL int same_owner_option;
 231
 232 /* If positive, preserve permissions when extracting.  */
 233 GLOBAL int same_permissions_option;
 234
 235 /* When set, strip the given number of file name components from the file name
 236    before extracting */
 237 GLOBAL size_t strip_name_components;
 238
 239 GLOBAL bool show_omitted_dirs_option;
 240
 241 GLOBAL bool sparse_option;
 242
 243 GLOBAL bool starting_file_option;
 244
 245 /* Specified maximum byte length of each tape volume (multiple of 1024).  */
 246 GLOBAL tarlong tape_length_option;
 247
 248 GLOBAL bool to_stdout_option;
 249
 250 GLOBAL bool totals_option;
 251
 252 GLOBAL bool touch_option;
 253
 254 GLOBAL char *to_command_option;
 255 GLOBAL bool ignore_command_error_option;
 256
 257 /* Restrict some potentially harmful tar options */
 258 GLOBAL bool restrict_option;
 259
 260 /* Return true if the extracted files are not being written to disk */
 261 #define EXTRACT_OVER_PIPE (to_stdout_option || to_command_option)
 262
 263 /* Count how many times the option has been set, multiple setting yields
 264    more verbose behavior.  Value 0 means no verbosity, 1 means file name
 265    only, 2 means file name and all attributes.  More than 2 is just like 2.  */
 266 GLOBAL int verbose_option;
 267
 268 GLOBAL bool verify_option;
 269
 270 /* Specified name of file containing the volume number.  */
 271 GLOBAL const char *volno_file_option;
 272
 273 /* Specified value or pattern.  */
 274 GLOBAL const char *volume_label_option;
 275 \f
 276 /* Other global variables.  */
 277
 278 /* File descriptor for archive file.  */
 279 GLOBAL int archive;
 280
 281 /* Nonzero when outputting to /dev/null.  */
 282 GLOBAL bool dev_null_output;
 283
 284 /* Timestamp for when we started execution.  */
 285 GLOBAL struct timespec start_time;
 286
 287 GLOBAL struct tar_stat_info current_stat_info;
 288
 289 /* List of tape drive names, number of such tape drives, allocated number,
 290    and current cursor in list.  */
 291 GLOBAL const char **archive_name_array;
 292 GLOBAL int archive_names;
 293 GLOBAL int allocated_archive_names;
 294 GLOBAL const char **archive_name_cursor;
 295
 296 /* Output index file name.  */
 297 GLOBAL char const *index_file_name;
 298
 299 /* Structure for keeping track of filenames and lists thereof.  */
 300 struct name
 301   {
 302     struct name *next;
 303     size_t length;              /* cached strlen(name) */
 304     uintmax_t found_count;      /* number of times a matching file has
 305                                    been found */
 306     int explicit;               /* was explicitely given in the command line */
 307     char firstch;               /* first char is literally matched */
 308     char regexp;                /* this name is a regexp, not literal */
 309     int change_dir;             /* set with the -C option */
 310     char const *dir_contents;   /* for incremental_option */
 311     char fake;                  /* dummy entry */
 312     char name[1];
 313   };
 314
 315 /* Obnoxious test to see if dimwit is trying to dump the archive.  */
 316 GLOBAL dev_t ar_dev;
 317 GLOBAL ino_t ar_ino;
 318
 319 GLOBAL bool seekable_archive;
 320
 321 GLOBAL dev_t root_device;
 322
 323 /* Unquote filenames */
 324 GLOBAL bool unquote_option;
 325
 326 GLOBAL bool test_label_option; /* Test archive volume label and exit */
 327
 328 /* When creating archive in verbose mode, list member names as stored in the
 329    archive */
 330 GLOBAL bool show_stored_names_option;
 331
 332 /* Delay setting modification times and permissions of extracted directories
 333    until the end of extraction. This variable helps correctly restore directory
 334    timestamps from archives with an unusual member order. It is automatically
 335    set for incremental archives. */
 336 GLOBAL bool delay_directory_restore_option;
 337
 338 \f
 339 /* Declarations for each module.  */
 340
 341 /* FIXME: compare.c should not directly handle the following variable,
 342    instead, this should be done in buffer.c only.  */
 343
 344 enum access_mode
 345 {
 346   ACCESS_READ,
 347   ACCESS_WRITE,
 348   ACCESS_UPDATE
 349 };
 350 extern enum access_mode access_mode;
 351
 352 /* Module buffer.c.  */
 353
 354 extern FILE *stdlis;
 355 extern bool write_archive_to_stdout;
 356 extern char *volume_label;
 357 extern char *continued_file_name;
 358 extern uintmax_t continued_file_size;
 359 extern uintmax_t continued_file_offset;
 360
 361 size_t available_space_after (union block *);
 362 off_t current_block_ordinal (void);
 363 void close_archive (void);
 364 void closeout_volume_number (void);
 365 union block *find_next_block (void);
 366 void flush_read (void);
 367 void flush_write (void);
 368 void flush_archive (void);
 369 void init_volume_number (void);
 370 void open_archive (enum access_mode);
 371 void print_total_written (void);
 372 void reset_eof (void);
 373 void set_next_block_after (union block *);
 374 void clear_read_error_count (void);
 375 void xclose (int fd);
 376 void archive_write_error (ssize_t) __attribute__ ((noreturn));
 377 void archive_read_error (void);
 378 off_t seek_archive (off_t size);
 379 void set_start_time (void);
 380
 381 void mv_begin (struct tar_stat_info *st);
 382 void mv_end (void);
 383 void mv_total_size (off_t size);
 384 void mv_size_left (off_t size);
 385
 386
 387 /* Module create.c.  */
 388
 389 enum dump_status
 390   {
 391     dump_status_ok,
 392     dump_status_short,
 393     dump_status_fail,
 394     dump_status_not_implemented
 395   };
 396
 397 bool file_dumpable_p (struct tar_stat_info *);
 398 void create_archive (void);
 399 void pad_archive (off_t size_left);
 400 void dump_file (char *, int, dev_t);
 401 union block *start_header (struct tar_stat_info *st);
 402 void finish_header (struct tar_stat_info *, union block *, off_t);
 403 void simple_finish_header (union block *header);
 404 union block * write_extended (bool global, struct tar_stat_info *st,
 405                               union block *old_header);
 406 union block *start_private_header (const char *name, size_t size);
 407 void write_eot (void);
 408 void check_links (void);
 409
 410 #define GID_TO_CHARS(val, where) gid_to_chars (val, where, sizeof (where))
 411 #define MAJOR_TO_CHARS(val, where) major_to_chars (val, where, sizeof (where))
 412 #define MINOR_TO_CHARS(val, where) minor_to_chars (val, where, sizeof (where))
 413 #define MODE_TO_CHARS(val, where) mode_to_chars (val, where, sizeof (where))
 414 #define OFF_TO_CHARS(val, where) off_to_chars (val, where, sizeof (where))
 415 #define SIZE_TO_CHARS(val, where) size_to_chars (val, where, sizeof (where))
 416 #define TIME_TO_CHARS(val, where) time_to_chars (val, where, sizeof (where))
 417 #define UID_TO_CHARS(val, where) uid_to_chars (val, where, sizeof (where))
 418 #define UINTMAX_TO_CHARS(val, where) uintmax_to_chars (val, where, sizeof (where))
 419 #define UNAME_TO_CHARS(name,buf) string_to_chars (name, buf, sizeof(buf))
 420 #define GNAME_TO_CHARS(name,buf) string_to_chars (name, buf, sizeof(buf))
 421
 422 bool gid_to_chars (gid_t, char *, size_t);
 423 bool major_to_chars (major_t, char *, size_t);
 424 bool minor_to_chars (minor_t, char *, size_t);
 425 bool mode_to_chars (mode_t, char *, size_t);
 426 bool off_to_chars (off_t, char *, size_t);
 427 bool size_to_chars (size_t, char *, size_t);
 428 bool time_to_chars (time_t, char *, size_t);
 429 bool uid_to_chars (uid_t, char *, size_t);
 430 bool uintmax_to_chars (uintmax_t, char *, size_t);
 431 void string_to_chars (char const *, char *, size_t);
 432
 433 /* Module diffarch.c.  */
 434
 435 extern bool now_verifying;
 436
 437 void diff_archive (void);
 438 void diff_init (void);
 439 void verify_volume (void);
 440
 441 /* Module extract.c.  */
 442
 443 void extr_init (void);
 444 void extract_archive (void);
 445 void extract_finish (void);
 446
 447 /* Module delete.c.  */
 448
 449 void delete_archive_members (void);
 450
 451 /* Module incremen.c.  */
 452
 453 char *get_directory_contents (char *, dev_t);
 454 void read_directory_file (void);
 455 void write_directory_file (void);
 456 void purge_directory (char const *);
 457 void list_dumpdir (char *buffer, size_t size);
 458 void update_parent_directory (const char *name);
 459
 460 size_t dumpdir_size (const char *p);
 461 void get_gnu_dumpdir (void);
 462
 463 /* Module list.c.  */
 464
 465 enum read_header
 466 {
 467   HEADER_STILL_UNREAD,          /* for when read_header has not been called */
 468   HEADER_SUCCESS,               /* header successfully read and checksummed */
 469   HEADER_SUCCESS_EXTENDED,      /* likewise, but we got an extended header */
 470   HEADER_ZERO_BLOCK,            /* zero block where header expected */
 471   HEADER_END_OF_FILE,           /* true end of file while header expected */
 472   HEADER_FAILURE                /* ill-formed header, or bad checksum */
 473 };
 474
 475 struct xheader
 476 {
 477   struct obstack *stk;
 478   size_t size;
 479   char *buffer;
 480 };
 481
 482 GLOBAL struct xheader extended_header;
 483 extern union block *current_header;
 484 extern enum archive_format current_format;
 485 extern size_t recent_long_name_blocks;
 486 extern size_t recent_long_link_blocks;
 487
 488 void decode_header (union block *, struct tar_stat_info *,
 489                     enum archive_format *, int);
 490 char const *tartime (struct timespec, bool);
 491
 492 #define GID_FROM_HEADER(where) gid_from_header (where, sizeof (where))
 493 #define MAJOR_FROM_HEADER(where) major_from_header (where, sizeof (where))
 494 #define MINOR_FROM_HEADER(where) minor_from_header (where, sizeof (where))
 495 #define MODE_FROM_HEADER(where) mode_from_header (where, sizeof (where))
 496 #define OFF_FROM_HEADER(where) off_from_header (where, sizeof (where))
 497 #define SIZE_FROM_HEADER(where) size_from_header (where, sizeof (where))
 498 #define TIME_FROM_HEADER(where) time_from_header (where, sizeof (where))
 499 #define UID_FROM_HEADER(where) uid_from_header (where, sizeof (where))
 500 #define UINTMAX_FROM_HEADER(where) uintmax_from_header (where, sizeof (where))
 501
 502 gid_t gid_from_header (const char *, size_t);
 503 major_t major_from_header (const char *, size_t);
 504 minor_t minor_from_header (const char *, size_t);
 505 mode_t mode_from_header (const char *, size_t);
 506 off_t off_from_header (const char *, size_t);
 507 size_t size_from_header (const char *, size_t);
 508 time_t time_from_header (const char *, size_t);
 509 uid_t uid_from_header (const char *, size_t);
 510 uintmax_t uintmax_from_header (const char *, size_t);
 511
 512 void list_archive (void);
 513 void print_for_mkdir (char *, int, mode_t);
 514 void print_header (struct tar_stat_info *, off_t);
 515 void read_and (void (*) (void));
 516 enum read_header read_header (bool);
 517 enum read_header tar_checksum (union block *header, bool silent);
 518 void skip_file (off_t);
 519 void skip_member (void);
 520
 521 /* Module mangle.c.  */
 522
 523 void extract_mangle (void);
 524
 525 /* Module misc.c.  */
 526
 527 void assign_string (char **, const char *);
 528 char *quote_copy_string (const char *);
 529 int unquote_string (char *);
 530
 531 void code_ns_fraction (int, char *);
 532 char const *code_timespec (struct timespec, char *);
 533 enum { BILLION = 1000000000, LOG10_BILLION = 9 };
 534 enum { TIMESPEC_STRSIZE_BOUND =
 535          UINTMAX_STRSIZE_BOUND + LOG10_BILLION + sizeof "-." - 1 };
 536
 537 size_t dot_dot_prefix_len (char const *);
 538
 539 enum remove_option
 540 {
 541   ORDINARY_REMOVE_OPTION,
 542   RECURSIVE_REMOVE_OPTION,
 543
 544   /* FIXME: The following value is never used. It seems to be intended
 545      as a placeholder for a hypothetical option that should instruct tar
 546      to recursively remove subdirectories in purge_directory(),
 547      as opposed to the functionality of --recursive-unlink
 548      (RECURSIVE_REMOVE_OPTION value), which removes them in
 549      prepare_to_extract() phase. However, with the addition of more
 550      meta-info to the incremental dumps, this should become unnecessary */
 551   WANT_DIRECTORY_REMOVE_OPTION
 552 };
 553 int remove_any_file (const char *, enum remove_option);
 554 bool maybe_backup_file (const char *, int);
 555 void undo_last_backup (void);
 556
 557 int deref_stat (bool, char const *, struct stat *);
 558
 559 int chdir_arg (char const *);
 560 void chdir_do (int);
 561
 562 void close_diag (char const *name);
 563 void open_diag (char const *name);
 564 void read_diag_details (char const *name, off_t offset, size_t size);
 565 void readlink_diag (char const *name);
 566 void savedir_diag (char const *name);
 567 void seek_diag_details (char const *, off_t);
 568 void stat_diag (char const *name);
 569 void write_error_details (char const *, size_t, size_t);
 570 void write_fatal (char const *) __attribute__ ((noreturn));
 571 void write_fatal_details (char const *, ssize_t, size_t)
 572      __attribute__ ((noreturn));
 573
 574 pid_t xfork (void);
 575 void xpipe (int[2]);
 576
 577 void *page_aligned_alloc (void **, size_t);
 578 int set_file_atime (int fd, char const *file,
 579                     struct timespec const timespec[2]);
 580
 581 /* Module names.c.  */
 582
 583 extern struct name *gnu_list_name;
 584
 585 void gid_to_gname (gid_t, char **gname);
 586 int gname_to_gid (char const *, gid_t *);
 587 void uid_to_uname (uid_t, char **uname);
 588 int uname_to_uid (char const *, uid_t *);
 589
 590 void init_names (void);
 591 void name_add (const char *);
 592 void name_init (void);
 593 void name_term (void);
 594 char *name_next (int);
 595 void name_gather (void);
 596 struct name *addname (char const *, int);
 597 int name_match (const char *);
 598 void names_notfound (void);
 599 void collect_and_sort_names (void);
 600 struct name *name_scan (const char *);
 601 char *name_from_list (void);
 602 void blank_name_list (void);
 603 char *new_name (const char *, const char *);
 604 size_t stripped_prefix_len (char const *file_name, size_t num);
 605 bool all_names_found (struct tar_stat_info *);
 606
 607 bool excluded_name (char const *);
 608
 609 void add_avoided_name (char const *);
 610 bool is_avoided_name (char const *);
 611 bool is_individual_file (char const *);
 612
 613 bool contains_dot_dot (char const *);
 614
 615 #define ISFOUND(c) ((occurrence_option == 0) ? (c)->found_count : \
 616                     (c)->found_count == occurrence_option)
 617 #define WASFOUND(c) ((occurrence_option == 0) ? (c)->found_count : \
 618                      (c)->found_count >= occurrence_option)
 619
 620 /* Module tar.c.  */
 621
 622 void usage (int);
 623
 624 int confirm (const char *, const char *);
 625 void request_stdin (const char *);
 626
 627 void tar_stat_init (struct tar_stat_info *st);
 628 void tar_stat_destroy (struct tar_stat_info *st);
 629 void usage (int) __attribute__ ((noreturn));
 630 int tar_timespec_cmp (struct timespec a, struct timespec b);
 631 const char *archive_format_string (enum archive_format fmt);
 632 const char *subcommand_string (enum subcommand c);
 633
 634 /* Module update.c.  */
 635
 636 extern char *output_start;
 637
 638 void update_archive (void);
 639
 640 /* Module xheader.c.  */
 641
 642 void xheader_decode (struct tar_stat_info *);
 643 void xheader_decode_global (void);
 644 void xheader_store (char const *, struct tar_stat_info const *, void const *);
 645 void xheader_read (union block *, size_t);
 646 void xheader_write (char type, char *name, struct xheader *xhdr);
 647 void xheader_write_global (void);
 648 void xheader_finish (struct xheader *);
 649 void xheader_destroy (struct xheader *);
 650 char *xheader_xhdr_name (struct tar_stat_info *st);
 651 char *xheader_ghdr_name (void);
 652 void xheader_write (char, char *, struct xheader *);
 653 void xheader_write_global (void);
 654 void xheader_set_option (char *string);
 655 void xheader_string_begin (void);
 656 void xheader_string_add (char const *s);
 657 void xheader_string_end (char const *keyword);
 658 bool xheader_keyword_deleted_p (const char *kw);
 659 char *xheader_format_name (struct tar_stat_info *st, const char *fmt,
 660                            size_t n);
 661
 662 /* Module system.c */
 663
 664 void sys_detect_dev_null_output (void);
 665 void sys_save_archive_dev_ino (void);
 666 void sys_drain_input_pipe (void);
 667 void sys_wait_for_child (pid_t);
 668 void sys_spawn_shell (void);
 669 bool sys_compare_uid (struct stat *a, struct stat *b);
 670 bool sys_compare_gid (struct stat *a, struct stat *b);
 671 bool sys_file_is_archive (struct tar_stat_info *p);
 672 bool sys_compare_links (struct stat *link_data, struct stat *stat_data);
 673 int sys_truncate (int fd);
 674 pid_t sys_child_open_for_compress (void);
 675 pid_t sys_child_open_for_uncompress (void);
 676 size_t sys_write_archive_buffer (void);
 677 bool sys_get_archive_stat (void);
 678 int sys_exec_command (char *file_name, int typechar, struct tar_stat_info *st);
 679 void sys_wait_command (void);
 680 int sys_exec_info_script (const char **archive_name, int volume_number);
 681
 682 /* Module compare.c */
 683 void report_difference (struct tar_stat_info *st, const char *message, ...);
 684
 685 /* Module sparse.c */
 686 bool sparse_file_p (struct tar_stat_info *);
 687 bool sparse_member_p (struct tar_stat_info *);
 688 bool sparse_fixup_header (struct tar_stat_info *);
 689 enum dump_status sparse_dump_file (int, struct tar_stat_info *);
 690 enum dump_status sparse_extract_file (int, struct tar_stat_info *, off_t *);
 691 enum dump_status sparse_skip_file (struct tar_stat_info *);
 692 bool sparse_diff_file (int, struct tar_stat_info *);
 693
 694 /* Module utf8.c */
 695 bool string_ascii_p (const char *str);
 696 bool utf8_convert (bool to_utf, char const *input, char **output);