src/system.h

   1 /* system-dependent definitions for coreutils
   2    Copyright (C) 1989, 1991-2010 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 #include <alloca.h>
  18
  19 /* Include sys/types.h before this file.  */
  20
  21 #if 2 <= __GLIBC__ && 2 <= __GLIBC_MINOR__
  22 # if ! defined _SYS_TYPES_H
  23 you must include <sys/types.h> before including this file
  24 # endif
  25 #endif
  26
  27 #include <sys/stat.h>
  28
  29 #if !defined HAVE_MKFIFO
  30 # define mkfifo(name, mode) mknod (name, (mode) | S_IFIFO, 0)
  31 #endif
  32
  33 #if HAVE_SYS_PARAM_H
  34 # include <sys/param.h>
  35 #endif
  36
  37 #include <unistd.h>
  38
  39 /* limits.h must come before pathmax.h because limits.h on some systems
  40    undefs PATH_MAX, whereas pathmax.h sets PATH_MAX.  */
  41 #include <limits.h>
  42
  43 #include "pathmax.h"
  44
  45 #include "configmake.h"
  46
  47 #include <sys/time.h>
  48 #include <time.h>
  49
  50 /* Since major is a function on SVR4, we can't use `ifndef major'.  */
  51 #if MAJOR_IN_MKDEV
  52 # include <sys/mkdev.h>
  53 # define HAVE_MAJOR
  54 #endif
  55 #if MAJOR_IN_SYSMACROS
  56 # include <sys/sysmacros.h>
  57 # define HAVE_MAJOR
  58 #endif
  59 #ifdef major                    /* Might be defined in sys/types.h.  */
  60 # define HAVE_MAJOR
  61 #endif
  62
  63 #ifndef HAVE_MAJOR
  64 # define major(dev)  (((dev) >> 8) & 0xff)
  65 # define minor(dev)  ((dev) & 0xff)
  66 # define makedev(maj, min)  (((maj) << 8) | (min))
  67 #endif
  68 #undef HAVE_MAJOR
  69
  70 #if ! defined makedev && defined mkdev
  71 # define makedev(maj, min)  mkdev (maj, min)
  72 #endif
  73
  74 /* Don't use bcopy!  Use memmove if source and destination may overlap,
  75    memcpy otherwise.  */
  76
  77 #include <string.h>
  78
  79 #include <errno.h>
  80
  81 /* Some systems don't define this; POSIX mentions it but says it is
  82    obsolete, so gnulib does not provide it either.  */
  83 #ifndef ENODATA
  84 # define ENODATA (-1)
  85 #endif
  86
  87 #include <stdbool.h>
  88 #include <stdlib.h>
  89 #include "version.h"
  90
  91 /* Exit statuses for programs like 'env' that exec other programs.  */
  92 enum
  93 {
  94   EXIT_TIMEDOUT = 124, /* Time expired before child completed.  */
  95   EXIT_CANCELED = 125, /* Internal error prior to exec attempt.  */
  96   EXIT_CANNOT_INVOKE = 126, /* Program located, but not usable.  */
  97   EXIT_ENOENT = 127 /* Could not find program to exec.  */
  98 };
  99
 100 #include "exitfail.h"
 101
 102 /* Set exit_failure to STATUS if that's not the default already.  */
 103 static inline void
 104 initialize_exit_failure (int status)
 105 {
 106   if (status != EXIT_FAILURE)
 107     exit_failure = status;
 108 }
 109
 110 #include <fcntl.h>
 111
 112 #include <dirent.h>
 113 #ifndef _D_EXACT_NAMLEN
 114 # define _D_EXACT_NAMLEN(dp) strlen ((dp)->d_name)
 115 #endif
 116
 117 enum
 118 {
 119   NOT_AN_INODE_NUMBER = 0
 120 };
 121
 122 #ifdef D_INO_IN_DIRENT
 123 # define D_INO(dp) (dp)->d_ino
 124 #else
 125 /* Some systems don't have inodes, so fake them to avoid lots of ifdefs.  */
 126 # define D_INO(dp) NOT_AN_INODE_NUMBER
 127 #endif
 128
 129 /* include here for SIZE_MAX.  */
 130 #include <inttypes.h>
 131
 132 /* Get or fake the disk device blocksize.
 133    Usually defined by sys/param.h (if at all).  */
 134 #if !defined DEV_BSIZE && defined BSIZE
 135 # define DEV_BSIZE BSIZE
 136 #endif
 137 #if !defined DEV_BSIZE && defined BBSIZE /* SGI */
 138 # define DEV_BSIZE BBSIZE
 139 #endif
 140 #ifndef DEV_BSIZE
 141 # define DEV_BSIZE 4096
 142 #endif
 143
 144 /* Extract or fake data from a `struct stat'.
 145    ST_BLKSIZE: Preferred I/O blocksize for the file, in bytes.
 146    ST_NBLOCKS: Number of blocks in the file, including indirect blocks.
 147    ST_NBLOCKSIZE: Size of blocks used when calculating ST_NBLOCKS.  */
 148 #ifndef HAVE_STRUCT_STAT_ST_BLOCKS
 149 # define ST_BLKSIZE(statbuf) DEV_BSIZE
 150 # if defined _POSIX_SOURCE || !defined BSIZE /* fileblocks.c uses BSIZE.  */
 151 #  define ST_NBLOCKS(statbuf) \
 152   ((statbuf).st_size / ST_NBLOCKSIZE + ((statbuf).st_size % ST_NBLOCKSIZE != 0))
 153 # else /* !_POSIX_SOURCE && BSIZE */
 154 #  define ST_NBLOCKS(statbuf) \
 155   (S_ISREG ((statbuf).st_mode) \
 156    || S_ISDIR ((statbuf).st_mode) \
 157    ? st_blocks ((statbuf).st_size) : 0)
 158 # endif /* !_POSIX_SOURCE && BSIZE */
 159 #else /* HAVE_STRUCT_STAT_ST_BLOCKS */
 160 /* Some systems, like Sequents, return st_blksize of 0 on pipes.
 161    Also, when running `rsh hpux11-system cat any-file', cat would
 162    determine that the output stream had an st_blksize of 2147421096.
 163    Conversely st_blksize can be 2 GiB (or maybe even larger) with XFS
 164    on 64-bit hosts.  Somewhat arbitrarily, limit the `optimal' block
 165    size to SIZE_MAX / 8 + 1.  (Dividing SIZE_MAX by only 4 wouldn't
 166    suffice, since "cat" sometimes multiplies the result by 4.)  If
 167    anyone knows of a system for which this limit is too small, please
 168    report it as a bug in this code.  */
 169 # define ST_BLKSIZE(statbuf) ((0 < (statbuf).st_blksize \
 170                                && (statbuf).st_blksize <= SIZE_MAX / 8 + 1) \
 171                               ? (statbuf).st_blksize : DEV_BSIZE)
 172 # if defined hpux || defined __hpux__ || defined __hpux
 173 /* HP-UX counts st_blocks in 1024-byte units.
 174    This loses when mixing HP-UX and BSD file systems with NFS.  */
 175 #  define ST_NBLOCKSIZE 1024
 176 # else /* !hpux */
 177 #  if defined _AIX && defined _I386
 178 /* AIX PS/2 counts st_blocks in 4K units.  */
 179 #   define ST_NBLOCKSIZE (4 * 1024)
 180 #  else /* not AIX PS/2 */
 181 #   if defined _CRAY
 182 #    define ST_NBLOCKS(statbuf) \
 183   (S_ISREG ((statbuf).st_mode) \
 184    || S_ISDIR ((statbuf).st_mode) \
 185    ? (statbuf).st_blocks * ST_BLKSIZE (statbuf) / ST_NBLOCKSIZE : 0)
 186 #   endif /* _CRAY */
 187 #  endif /* not AIX PS/2 */
 188 # endif /* !hpux */
 189 #endif /* HAVE_STRUCT_STAT_ST_BLOCKS */
 190
 191 #ifndef ST_NBLOCKS
 192 # define ST_NBLOCKS(statbuf) ((statbuf).st_blocks)
 193 #endif
 194
 195 #ifndef ST_NBLOCKSIZE
 196 # ifdef S_BLKSIZE
 197 #  define ST_NBLOCKSIZE S_BLKSIZE
 198 # else
 199 #  define ST_NBLOCKSIZE 512
 200 # endif
 201 #endif
 202
 203 /* Redirection and wildcarding when done by the utility itself.
 204    Generally a noop, but used in particular for native VMS. */
 205 #ifndef initialize_main
 206 # define initialize_main(ac, av)
 207 #endif
 208
 209 #include "stat-macros.h"
 210
 211 #include "timespec.h"
 212
 213 #include <ctype.h>
 214
 215 /* ISDIGIT differs from isdigit, as follows:
 216    - Its arg may be any int or unsigned int; it need not be an unsigned char
 217      or EOF.
 218    - It's typically faster.
 219    POSIX says that only '0' through '9' are digits.  Prefer ISDIGIT to
 220    isdigit unless it's important to use the locale's definition
 221    of `digit' even when the host does not conform to POSIX.  */
 222 #define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9)
 223
 224 /* Convert a possibly-signed character to an unsigned character.  This is
 225    a bit safer than casting to unsigned char, since it catches some type
 226    errors that the cast doesn't.  */
 227 static inline unsigned char to_uchar (char ch) { return ch; }
 228
 229 #include <locale.h>
 230
 231 /* Take care of NLS matters.  */
 232
 233 #include "gettext.h"
 234 #if ! ENABLE_NLS
 235 # undef textdomain
 236 # define textdomain(Domainname) /* empty */
 237 # undef bindtextdomain
 238 # define bindtextdomain(Domainname, Dirname) /* empty */
 239 #endif
 240
 241 #define _(msgid) gettext (msgid)
 242 #define N_(msgid) msgid
 243
 244 /* Return a value that pluralizes the same way that N does, in all
 245    languages we know of.  */
 246 static inline unsigned long int
 247 select_plural (uintmax_t n)
 248 {
 249   /* Reduce by a power of ten, but keep it away from zero.  The
 250      gettext manual says 1000000 should be safe.  */
 251   enum { PLURAL_REDUCER = 1000000 };
 252   return (n <= ULONG_MAX ? n : n % PLURAL_REDUCER + PLURAL_REDUCER);
 253 }
 254
 255 #define STREQ(a, b) (strcmp (a, b) == 0)
 256
 257 #if !HAVE_DECL_GETLOGIN
 258 char *getlogin ();
 259 #endif
 260
 261 #if !HAVE_DECL_TTYNAME
 262 char *ttyname ();
 263 #endif
 264
 265 #if !HAVE_DECL_GETEUID
 266 uid_t geteuid ();
 267 #endif
 268
 269 #if !HAVE_DECL_GETPWUID
 270 struct passwd *getpwuid ();
 271 #endif
 272
 273 #if !HAVE_DECL_GETGRGID
 274 struct group *getgrgid ();
 275 #endif
 276
 277 #if !HAVE_DECL_GETUID
 278 uid_t getuid ();
 279 #endif
 280
 281 #include "xalloc.h"
 282 #include "verify.h"
 283
 284 /* This is simply a shorthand for the common case in which
 285    the third argument to x2nrealloc would be `sizeof *(P)'.
 286    Ensure that sizeof *(P) is *not* 1.  In that case, it'd be
 287    better to use X2REALLOC, although not strictly necessary.  */
 288 #define X2NREALLOC(P, PN) ((void) verify_true (sizeof *(P) != 1), \
 289                            x2nrealloc (P, PN, sizeof *(P)))
 290
 291 /* Using x2realloc (when appropriate) usually makes your code more
 292    readable than using x2nrealloc, but it also makes it so your
 293    code will malfunction if sizeof *(P) ever becomes 2 or greater.
 294    So use this macro instead of using x2realloc directly.  */
 295 #define X2REALLOC(P, PN) ((void) verify_true (sizeof *(P) == 1), \
 296                           x2realloc (P, PN))
 297
 298 #include "unlocked-io.h"
 299 #include "same-inode.h"
 300
 301 #include "dirname.h"
 302 #include "openat.h"
 303
 304 static inline bool
 305 dot_or_dotdot (char const *file_name)
 306 {
 307   if (file_name[0] == '.')
 308     {
 309       char sep = file_name[(file_name[1] == '.') + 1];
 310       return (! sep || ISSLASH (sep));
 311     }
 312   else
 313     return false;
 314 }
 315
 316 /* A wrapper for readdir so that callers don't see entries for `.' or `..'.  */
 317 static inline struct dirent const *
 318 readdir_ignoring_dot_and_dotdot (DIR *dirp)
 319 {
 320   while (1)
 321     {
 322       struct dirent const *dp = readdir (dirp);
 323       if (dp == NULL || ! dot_or_dotdot (dp->d_name))
 324         return dp;
 325     }
 326 }
 327
 328 /* Return true if DIR is determined to be an empty directory.  */
 329 static inline bool
 330 is_empty_dir (int fd_cwd, char const *dir)
 331 {
 332   DIR *dirp;
 333   struct dirent const *dp;
 334   int saved_errno;
 335   int fd = openat (fd_cwd, dir,
 336                    (O_RDONLY | O_DIRECTORY
 337                     | O_NOCTTY | O_NOFOLLOW | O_NONBLOCK));
 338
 339   if (fd < 0)
 340     return false;
 341
 342   dirp = fdopendir (fd);
 343   if (dirp == NULL)
 344     {
 345       close (fd);
 346       return false;
 347     }
 348
 349   errno = 0;
 350   dp = readdir_ignoring_dot_and_dotdot (dirp);
 351   saved_errno = errno;
 352   closedir (dirp);
 353   if (dp != NULL)
 354     return false;
 355   return saved_errno == 0 ? true : false;
 356 }
 357
 358 /* Factor out some of the common --help and --version processing code.  */
 359
 360 /* These enum values cannot possibly conflict with the option values
 361    ordinarily used by commands, including CHAR_MAX + 1, etc.  Avoid
 362    CHAR_MIN - 1, as it may equal -1, the getopt end-of-options value.  */
 363 enum
 364 {
 365   GETOPT_HELP_CHAR = (CHAR_MIN - 2),
 366   GETOPT_VERSION_CHAR = (CHAR_MIN - 3)
 367 };
 368
 369 #define GETOPT_HELP_OPTION_DECL \
 370   "help", no_argument, NULL, GETOPT_HELP_CHAR
 371 #define GETOPT_VERSION_OPTION_DECL \
 372   "version", no_argument, NULL, GETOPT_VERSION_CHAR
 373 #define GETOPT_SELINUX_CONTEXT_OPTION_DECL \
 374   "context", required_argument, NULL, 'Z'
 375
 376 #define case_GETOPT_HELP_CHAR                   \
 377   case GETOPT_HELP_CHAR:                        \
 378     usage (EXIT_SUCCESS);                       \
 379     break;
 380
 381 /* Program_name must be a literal string.
 382    Usually it is just PROGRAM_NAME.  */
 383 #define USAGE_BUILTIN_WARNING \
 384   _("\n" \
 385 "NOTE: your shell may have its own version of %s, which usually supersedes\n" \
 386 "the version described here.  Please refer to your shell's documentation\n" \
 387 "for details about the options it supports.\n")
 388
 389 #define HELP_OPTION_DESCRIPTION \
 390   _("      --help     display this help and exit\n")
 391 #define VERSION_OPTION_DESCRIPTION \
 392   _("      --version  output version information and exit\n")
 393
 394 #include "closein.h"
 395 #include "closeout.h"
 396
 397 #define emit_bug_reporting_address unused__emit_bug_reporting_address
 398 #include "version-etc.h"
 399 #undef emit_bug_reporting_address
 400
 401 #include "propername.h"
 402 /* Define away proper_name (leaving proper_name_utf8, which affects far
 403    fewer programs), since it's not worth the cost of adding ~17KB to
 404    the x86_64 text size of every single program.  This avoids a 40%
 405    (almost ~2MB) increase in the on-disk space utilization for the set
 406    of the 100 binaries. */
 407 #define proper_name(x) (x)
 408
 409 #include "progname.h"
 410
 411 #define case_GETOPT_VERSION_CHAR(Program_name, Authors)                 \
 412   case GETOPT_VERSION_CHAR:                                             \
 413     version_etc (stdout, Program_name, PACKAGE_NAME, Version, Authors,  \
 414                  (char *) NULL);                                        \
 415     exit (EXIT_SUCCESS);                                                \
 416     break;
 417
 418 #ifndef MAX
 419 # define MAX(a, b) ((a) > (b) ? (a) : (b))
 420 #endif
 421
 422 #ifndef MIN
 423 # define MIN(a,b) (((a) < (b)) ? (a) : (b))
 424 #endif
 425
 426 #include "intprops.h"
 427
 428 #ifndef SSIZE_MAX
 429 # define SSIZE_MAX TYPE_MAXIMUM (ssize_t)
 430 #endif
 431
 432 #ifndef OFF_T_MIN
 433 # define OFF_T_MIN TYPE_MINIMUM (off_t)
 434 #endif
 435
 436 #ifndef OFF_T_MAX
 437 # define OFF_T_MAX TYPE_MAXIMUM (off_t)
 438 #endif
 439
 440 #ifndef UID_T_MAX
 441 # define UID_T_MAX TYPE_MAXIMUM (uid_t)
 442 #endif
 443
 444 #ifndef GID_T_MAX
 445 # define GID_T_MAX TYPE_MAXIMUM (gid_t)
 446 #endif
 447
 448 #ifndef PID_T_MAX
 449 # define PID_T_MAX TYPE_MAXIMUM (pid_t)
 450 #endif
 451
 452 /* Use this to suppress gcc's `...may be used before initialized' warnings. */
 453 #ifdef lint
 454 # define IF_LINT(Code) Code
 455 #else
 456 # define IF_LINT(Code) /* empty */
 457 #endif
 458
 459 /* With -Dlint, avoid warnings from gcc about code like mbstate_t m = {0,};
 460    by wasting space on a static variable of the same type, that is thus
 461    guaranteed to be initialized to 0, and use that on the RHS.  */
 462 #define DZA_CONCAT0(x,y) x ## y
 463 #define DZA_CONCAT(x,y) DZA_CONCAT0 (x, y)
 464 #ifdef lint
 465 # define DECLARE_ZEROED_AGGREGATE(Type, Var) \
 466    static Type DZA_CONCAT (s0_, __LINE__); Type Var = DZA_CONCAT (s0_, __LINE__)
 467 #else
 468 # define DECLARE_ZEROED_AGGREGATE(Type, Var) \
 469   Type Var = { 0, }
 470 #endif
 471
 472 #ifndef __attribute__
 473 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8)
 474 #  define __attribute__(x) /* empty */
 475 # endif
 476 #endif
 477
 478 #ifndef ATTRIBUTE_NORETURN
 479 # define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
 480 #endif
 481
 482 #ifndef ATTRIBUTE_UNUSED
 483 # define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
 484 #endif
 485
 486 /* The warn_unused_result attribute appeared first in gcc-3.4.0 */
 487 #undef ATTRIBUTE_WARN_UNUSED_RESULT
 488 #if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 4)
 489 # define ATTRIBUTE_WARN_UNUSED_RESULT /* empty */
 490 #else
 491 # define ATTRIBUTE_WARN_UNUSED_RESULT __attribute__ ((__warn_unused_result__))
 492 #endif
 493
 494 #if defined strdupa
 495 # define ASSIGN_STRDUPA(DEST, S)                \
 496   do { DEST = strdupa (S); } while (0)
 497 #else
 498 # define ASSIGN_STRDUPA(DEST, S)                \
 499   do                                            \
 500     {                                           \
 501       const char *s_ = (S);                     \
 502       size_t len_ = strlen (s_) + 1;            \
 503       char *tmp_dest_ = alloca (len_);          \
 504       DEST = memcpy (tmp_dest_, s_, len_);      \
 505     }                                           \
 506   while (0)
 507 #endif
 508
 509 #if ! HAVE_SYNC
 510 # define sync() /* empty */
 511 #endif
 512
 513 /* Compute the greatest common divisor of U and V using Euclid's
 514    algorithm.  U and V must be nonzero.  */
 515
 516 static inline size_t
 517 gcd (size_t u, size_t v)
 518 {
 519   do
 520     {
 521       size_t t = u % v;
 522       u = v;
 523       v = t;
 524     }
 525   while (v);
 526
 527   return u;
 528 }
 529
 530 /* Compute the least common multiple of U and V.  U and V must be
 531    nonzero.  There is no overflow checking, so callers should not
 532    specify outlandish sizes.  */
 533
 534 static inline size_t
 535 lcm (size_t u, size_t v)
 536 {
 537   return u * (v / gcd (u, v));
 538 }
 539
 540 /* Return PTR, aligned upward to the next multiple of ALIGNMENT.
 541    ALIGNMENT must be nonzero.  The caller must arrange for ((char *)
 542    PTR) through ((char *) PTR + ALIGNMENT - 1) to be addressable
 543    locations.  */
 544
 545 static inline void *
 546 ptr_align (void const *ptr, size_t alignment)
 547 {
 548   char const *p0 = ptr;
 549   char const *p1 = p0 + alignment - 1;
 550   return (void *) (p1 - (size_t) p1 % alignment);
 551 }
 552
 553 /* If 10*Accum + Digit_val is larger than the maximum value for Type,
 554    then don't update Accum and return false to indicate it would
 555    overflow.  Otherwise, set Accum to that new value and return true.
 556    Verify at compile-time that Type is Accum's type, and that Type is
 557    unsigned.  Accum must be an object, so that we can take its
 558    address.  Accum and Digit_val may be evaluated multiple times.
 559
 560    The "Added check" below is not strictly required, but it causes GCC
 561    to return a nonzero exit status instead of merely a warning
 562    diagnostic, and that is more useful.  */
 563
 564 #define DECIMAL_DIGIT_ACCUMULATE(Accum, Digit_val, Type)                \
 565   (                                                                     \
 566    (void) (&(Accum) == (Type *) NULL),  /* The type matches.  */        \
 567    (void) verify_true (! TYPE_SIGNED (Type)), /* The type is unsigned.  */ \
 568    (void) verify_true (sizeof (Accum) == sizeof (Type)), /* Added check.  */ \
 569    (((Type) -1 / 10 < (Accum)                                           \
 570      || (Type) ((Accum) * 10 + (Digit_val)) < (Accum))                  \
 571     ? false : (((Accum) = (Accum) * 10 + (Digit_val)), true))           \
 572   )
 573
 574 static inline void
 575 emit_size_note (void)
 576 {
 577   fputs (_("\n\
 578 SIZE may be (or may be an integer optionally followed by) one of following:\n\
 579 KB 1000, K 1024, MB 1000*1000, M 1024*1024, and so on for G, T, P, E, Z, Y.\n\
 580 "), stdout);
 581 }
 582
 583 static inline void
 584 emit_blocksize_note (char const *program)
 585 {
 586   printf (_("\n\
 587 Display values are in units of the first available SIZE from --block-size,\n\
 588 and the %s_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables.\n\
 589 Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set).\n\
 590 "), program);
 591 }
 592
 593 static inline void
 594 emit_ancillary_info (void)
 595 {
 596   printf (_("\nReport %s bugs to %s\n"), last_component (program_name),
 597           PACKAGE_BUGREPORT);
 598   /* FIXME 2010: use AC_PACKAGE_URL once we require autoconf-2.64 */
 599   printf (_("%s home page: <http://www.gnu.org/software/%s/>\n"),
 600           PACKAGE_NAME, PACKAGE);
 601   fputs (_("General help using GNU software: <http://www.gnu.org/gethelp/>\n"),
 602          stdout);
 603   /* Don't output this redundant message for English locales.
 604      Note we still output for 'C' so that it gets included in the man page.  */
 605   const char *lc_messages = setlocale (LC_MESSAGES, NULL);
 606   if (lc_messages && strncmp (lc_messages, "en_", 3))
 607     {
 608       /* TRANSLATORS: Replace LANG_CODE in this URL with your language code
 609          <http://translationproject.org/team/LANG_CODE.html> to form one of
 610          the URLs at http://translationproject.org/team/.  Otherwise, replace
 611          the entire URL with your translation team's email address.  */
 612       printf (_("Report %s translation bugs to "
 613                 "<http://translationproject.org/team/>\n"),
 614                 last_component (program_name));
 615     }
 616   printf (_("For complete documentation, run: "
 617             "info coreutils '%s invocation'\n"), last_component (program_name));
 618 }
 619
 620 #include "inttostr.h"
 621
 622 static inline char *
 623 timetostr (time_t t, char *buf)
 624 {
 625   return (TYPE_SIGNED (time_t)
 626           ? imaxtostr (t, buf)
 627           : umaxtostr (t, buf));
 628 }
 629
 630 static inline char *
 631 bad_cast (char const *s)
 632 {
 633   return (char *) s;
 634 }
 635
 636 /* As of Mar 2009, 32KiB is determined to be the minimium
 637    blksize to best minimize system call overhead.
 638    This can be tested with this script with the results
 639    shown for a 1.7GHz pentium-m with 2GB of 400MHz DDR2 RAM:
 640
 641    for i in $(seq 0 10); do
 642      size=$((8*1024**3)) #ensure this is big enough
 643      bs=$((1024*2**$i))
 644      printf "%7s=" $bs
 645      dd bs=$bs if=/dev/zero of=/dev/null count=$(($size/$bs)) 2>&1 |
 646      sed -n 's/.* \([0-9.]* [GM]B\/s\)/\1/p'
 647    done
 648
 649       1024=734 MB/s
 650       2048=1.3 GB/s
 651       4096=2.4 GB/s
 652       8192=3.5 GB/s
 653      16384=3.9 GB/s
 654      32768=5.2 GB/s
 655      65536=5.3 GB/s
 656     131072=5.5 GB/s
 657     262144=5.7 GB/s
 658     524288=5.7 GB/s
 659    1048576=5.8 GB/s
 660
 661    Note that this is to minimize system call overhead.
 662    Other values may be appropriate to minimize file system
 663    or disk overhead.  For example on my current GNU/Linux system
 664    the readahead setting is 128KiB which was read using:
 665
 666    file="."
 667    device=$(df -P --local "$file" | tail -n1 | cut -d' ' -f1)
 668    echo $(( $(blockdev --getra $device) * 512 ))
 669
 670    However there isn't a portable way to get the above.
 671    In the future we could use the above method if available
 672    and default to io_blksize() if not.
 673  */
 674 enum { IO_BUFSIZE = 32*1024 };
 675 static inline size_t
 676 io_blksize (struct stat sb)
 677 {
 678   return MAX (IO_BUFSIZE, ST_BLKSIZE (sb));
 679 }
 680
 681 void usage (int status) ATTRIBUTE_NORETURN;
 682
 683 #define emit_cycle_warning(file_name)   \
 684   do                                    \
 685     {                                   \
 686       error (0, 0, _("\
 687 WARNING: Circular directory structure.\n\
 688 This almost certainly means that you have a corrupted file system.\n\
 689 NOTIFY YOUR SYSTEM MANAGER.\n\
 690 The following directory is part of the cycle:\n  %s\n"), \
 691              quote (file_name));        \
 692     }                                   \
 693   while (0)
 694
 695 #ifndef ARRAY_CARDINALITY
 696 # define ARRAY_CARDINALITY(Array) (sizeof (Array) / sizeof *(Array))
 697 #endif