src/system.h

   1 /* system-dependent definitions for coreutils
   2    Copyright (C) 1989, 1991-2009 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 #if TIME_WITH_SYS_TIME
  48 # include <sys/time.h>
  49 # include <time.h>
  50 #else
  51 # if HAVE_SYS_TIME_H
  52 #  include <sys/time.h>
  53 # else
  54 #  include <time.h>
  55 # endif
  56 #endif
  57
  58 /* Since major is a function on SVR4, we can't use `ifndef major'.  */
  59 #if MAJOR_IN_MKDEV
  60 # include <sys/mkdev.h>
  61 # define HAVE_MAJOR
  62 #endif
  63 #if MAJOR_IN_SYSMACROS
  64 # include <sys/sysmacros.h>
  65 # define HAVE_MAJOR
  66 #endif
  67 #ifdef major                    /* Might be defined in sys/types.h.  */
  68 # define HAVE_MAJOR
  69 #endif
  70
  71 #ifndef HAVE_MAJOR
  72 # define major(dev)  (((dev) >> 8) & 0xff)
  73 # define minor(dev)  ((dev) & 0xff)
  74 # define makedev(maj, min)  (((maj) << 8) | (min))
  75 #endif
  76 #undef HAVE_MAJOR
  77
  78 #if ! defined makedev && defined mkdev
  79 # define makedev(maj, min)  mkdev (maj, min)
  80 #endif
  81
  82 /* Don't use bcopy!  Use memmove if source and destination may overlap,
  83    memcpy otherwise.  */
  84
  85 #include <string.h>
  86
  87 #include <errno.h>
  88
  89 /* Some systems don't define the following symbols.  */
  90 #ifndef EDQUOT
  91 # define EDQUOT (-1)
  92 #endif
  93 #ifndef EISDIR
  94 # define EISDIR (-1)
  95 #endif
  96 #ifndef ENOSYS
  97 # define ENOSYS (-1)
  98 #endif
  99 #ifndef ENODATA
 100 # define ENODATA (-1)
 101 #endif
 102
 103 #include <stdbool.h>
 104 #include <stdlib.h>
 105 #include "version.h"
 106
 107 /* Exit statuses for programs like 'env' that exec other programs.  */
 108 enum
 109 {
 110   EXIT_CANNOT_INVOKE = 126,
 111   EXIT_ENOENT = 127
 112 };
 113
 114 #include "exitfail.h"
 115
 116 /* Set exit_failure to STATUS if that's not the default already.  */
 117 static inline void
 118 initialize_exit_failure (int status)
 119 {
 120   if (status != EXIT_FAILURE)
 121     exit_failure = status;
 122 }
 123
 124 #include <fcntl.h>
 125
 126 #ifndef F_OK
 127 # define F_OK 0
 128 # define X_OK 1
 129 # define W_OK 2
 130 # define R_OK 4
 131 #endif
 132
 133 #include <dirent.h>
 134 #ifndef _D_EXACT_NAMLEN
 135 # define _D_EXACT_NAMLEN(dp) strlen ((dp)->d_name)
 136 #endif
 137
 138 enum
 139 {
 140   NOT_AN_INODE_NUMBER = 0
 141 };
 142
 143 #ifdef D_INO_IN_DIRENT
 144 # define D_INO(dp) (dp)->d_ino
 145 #else
 146 /* Some systems don't have inodes, so fake them to avoid lots of ifdefs.  */
 147 # define D_INO(dp) NOT_AN_INODE_NUMBER
 148 #endif
 149
 150 /* include here for SIZE_MAX.  */
 151 #include <inttypes.h>
 152
 153 /* Get or fake the disk device blocksize.
 154    Usually defined by sys/param.h (if at all).  */
 155 #if !defined DEV_BSIZE && defined BSIZE
 156 # define DEV_BSIZE BSIZE
 157 #endif
 158 #if !defined DEV_BSIZE && defined BBSIZE /* SGI */
 159 # define DEV_BSIZE BBSIZE
 160 #endif
 161 #ifndef DEV_BSIZE
 162 # define DEV_BSIZE 4096
 163 #endif
 164
 165 /* Extract or fake data from a `struct stat'.
 166    ST_BLKSIZE: Preferred I/O blocksize for the file, in bytes.
 167    ST_NBLOCKS: Number of blocks in the file, including indirect blocks.
 168    ST_NBLOCKSIZE: Size of blocks used when calculating ST_NBLOCKS.  */
 169 #ifndef HAVE_STRUCT_STAT_ST_BLOCKS
 170 # define ST_BLKSIZE(statbuf) DEV_BSIZE
 171 # if defined _POSIX_SOURCE || !defined BSIZE /* fileblocks.c uses BSIZE.  */
 172 #  define ST_NBLOCKS(statbuf) \
 173   ((statbuf).st_size / ST_NBLOCKSIZE + ((statbuf).st_size % ST_NBLOCKSIZE != 0))
 174 # else /* !_POSIX_SOURCE && BSIZE */
 175 #  define ST_NBLOCKS(statbuf) \
 176   (S_ISREG ((statbuf).st_mode) \
 177    || S_ISDIR ((statbuf).st_mode) \
 178    ? st_blocks ((statbuf).st_size) : 0)
 179 # endif /* !_POSIX_SOURCE && BSIZE */
 180 #else /* HAVE_STRUCT_STAT_ST_BLOCKS */
 181 /* Some systems, like Sequents, return st_blksize of 0 on pipes.
 182    Also, when running `rsh hpux11-system cat any-file', cat would
 183    determine that the output stream had an st_blksize of 2147421096.
 184    Conversely st_blksize can be 2 GiB (or maybe even larger) with XFS
 185    on 64-bit hosts.  Somewhat arbitrarily, limit the `optimal' block
 186    size to SIZE_MAX / 8 + 1.  (Dividing SIZE_MAX by only 4 wouldn't
 187    suffice, since "cat" sometimes multiplies the result by 4.)  If
 188    anyone knows of a system for which this limit is too small, please
 189    report it as a bug in this code.  */
 190 # define ST_BLKSIZE(statbuf) ((0 < (statbuf).st_blksize \
 191                                && (statbuf).st_blksize <= SIZE_MAX / 8 + 1) \
 192                               ? (statbuf).st_blksize : DEV_BSIZE)
 193 # if defined hpux || defined __hpux__ || defined __hpux
 194 /* HP-UX counts st_blocks in 1024-byte units.
 195    This loses when mixing HP-UX and BSD file systems with NFS.  */
 196 #  define ST_NBLOCKSIZE 1024
 197 # else /* !hpux */
 198 #  if defined _AIX && defined _I386
 199 /* AIX PS/2 counts st_blocks in 4K units.  */
 200 #   define ST_NBLOCKSIZE (4 * 1024)
 201 #  else /* not AIX PS/2 */
 202 #   if defined _CRAY
 203 #    define ST_NBLOCKS(statbuf) \
 204   (S_ISREG ((statbuf).st_mode) \
 205    || S_ISDIR ((statbuf).st_mode) \
 206    ? (statbuf).st_blocks * ST_BLKSIZE(statbuf)/ST_NBLOCKSIZE : 0)
 207 #   endif /* _CRAY */
 208 #  endif /* not AIX PS/2 */
 209 # endif /* !hpux */
 210 #endif /* HAVE_STRUCT_STAT_ST_BLOCKS */
 211
 212 #ifndef ST_NBLOCKS
 213 # define ST_NBLOCKS(statbuf) ((statbuf).st_blocks)
 214 #endif
 215
 216 #ifndef ST_NBLOCKSIZE
 217 # ifdef S_BLKSIZE
 218 #  define ST_NBLOCKSIZE S_BLKSIZE
 219 # else
 220 #  define ST_NBLOCKSIZE 512
 221 # endif
 222 #endif
 223
 224 /* Redirection and wildcarding when done by the utility itself.
 225    Generally a noop, but used in particular for native VMS. */
 226 #ifndef initialize_main
 227 # define initialize_main(ac, av)
 228 #endif
 229
 230 #include "stat-macros.h"
 231
 232 #include "timespec.h"
 233
 234 #include <ctype.h>
 235
 236 #if ! (defined isblank || HAVE_DECL_ISBLANK)
 237 # define isblank(c) ((c) == ' ' || (c) == '\t')
 238 #endif
 239
 240 /* ISDIGIT differs from isdigit, as follows:
 241    - Its arg may be any int or unsigned int; it need not be an unsigned char
 242      or EOF.
 243    - It's typically faster.
 244    POSIX says that only '0' through '9' are digits.  Prefer ISDIGIT to
 245    isdigit unless it's important to use the locale's definition
 246    of `digit' even when the host does not conform to POSIX.  */
 247 #define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9)
 248
 249 /* Convert a possibly-signed character to an unsigned character.  This is
 250    a bit safer than casting to unsigned char, since it catches some type
 251    errors that the cast doesn't.  */
 252 static inline unsigned char to_uchar (char ch) { return ch; }
 253
 254 #include <locale.h>
 255
 256 /* Take care of NLS matters.  */
 257
 258 #include "gettext.h"
 259 #if ! ENABLE_NLS
 260 # undef textdomain
 261 # define textdomain(Domainname) /* empty */
 262 # undef bindtextdomain
 263 # define bindtextdomain(Domainname, Dirname) /* empty */
 264 #endif
 265
 266 #define _(msgid) gettext (msgid)
 267 #define N_(msgid) msgid
 268
 269 /* Return a value that pluralizes the same way that N does, in all
 270    languages we know of.  */
 271 static inline unsigned long int
 272 select_plural (uintmax_t n)
 273 {
 274   /* Reduce by a power of ten, but keep it away from zero.  The
 275      gettext manual says 1000000 should be safe.  */
 276   enum { PLURAL_REDUCER = 1000000 };
 277   return (n <= ULONG_MAX ? n : n % PLURAL_REDUCER + PLURAL_REDUCER);
 278 }
 279
 280 #define STREQ(a, b) (strcmp (a, b) == 0)
 281
 282 #if !HAVE_DECL_FREE
 283 void free ();
 284 #endif
 285
 286 #if !HAVE_DECL_MALLOC
 287 char *malloc ();
 288 #endif
 289
 290 #if !HAVE_DECL_MEMCHR
 291 char *memchr ();
 292 #endif
 293
 294 #if !HAVE_DECL_REALLOC
 295 char *realloc ();
 296 #endif
 297
 298 #if !HAVE_DECL_GETENV
 299 char *getenv ();
 300 #endif
 301
 302 #if !HAVE_DECL_LSEEK
 303 off_t lseek ();
 304 #endif
 305
 306 #if !HAVE_DECL_GETLOGIN
 307 char *getlogin ();
 308 #endif
 309
 310 #if !HAVE_DECL_TTYNAME
 311 char *ttyname ();
 312 #endif
 313
 314 #if !HAVE_DECL_GETEUID
 315 uid_t geteuid ();
 316 #endif
 317
 318 #if !HAVE_DECL_GETPWUID
 319 struct passwd *getpwuid ();
 320 #endif
 321
 322 #if !HAVE_DECL_GETGRGID
 323 struct group *getgrgid ();
 324 #endif
 325
 326 #if !HAVE_DECL_GETUID
 327 uid_t getuid ();
 328 #endif
 329
 330 #include "xalloc.h"
 331 #include "verify.h"
 332
 333 /* This is simply a shorthand for the common case in which
 334    the third argument to x2nrealloc would be `sizeof *(P)'.
 335    Ensure that sizeof *(P) is *not* 1.  In that case, it'd be
 336    better to use X2REALLOC, although not strictly necessary.  */
 337 #define X2NREALLOC(P, PN) ((void) verify_true (sizeof *(P) != 1), \
 338                            x2nrealloc (P, PN, sizeof *(P)))
 339
 340 /* Using x2realloc (when appropriate) usually makes your code more
 341    readable than using x2nrealloc, but it also makes it so your
 342    code will malfunction if sizeof *(P) ever becomes 2 or greater.
 343    So use this macro instead of using x2realloc directly.  */
 344 #define X2REALLOC(P, PN) ((void) verify_true (sizeof *(P) == 1), \
 345                           x2realloc (P, PN))
 346
 347 #include "unlocked-io.h"
 348 #include "same-inode.h"
 349
 350 #include "dirname.h"
 351 #include "openat.h"
 352
 353 static inline bool
 354 dot_or_dotdot (char const *file_name)
 355 {
 356   if (file_name[0] == '.')
 357     {
 358       char sep = file_name[(file_name[1] == '.') + 1];
 359       return (! sep || ISSLASH (sep));
 360     }
 361   else
 362     return false;
 363 }
 364
 365 /* A wrapper for readdir so that callers don't see entries for `.' or `..'.  */
 366 static inline struct dirent const *
 367 readdir_ignoring_dot_and_dotdot (DIR *dirp)
 368 {
 369   while (1)
 370     {
 371       struct dirent const *dp = readdir (dirp);
 372       if (dp == NULL || ! dot_or_dotdot (dp->d_name))
 373         return dp;
 374     }
 375 }
 376
 377 /* Return true if DIR is determined to be an empty directory.  */
 378 static inline bool
 379 is_empty_dir (int fd_cwd, char const *dir)
 380 {
 381   DIR *dirp;
 382   struct dirent const *dp;
 383   int saved_errno;
 384   int fd = openat (fd_cwd, dir,
 385                    (O_RDONLY | O_DIRECTORY
 386                     | O_NOCTTY | O_NOFOLLOW | O_NONBLOCK));
 387
 388   if (fd < 0)
 389     return false;
 390
 391   dirp = fdopendir (fd);
 392   if (dirp == NULL)
 393     {
 394       close (fd);
 395       return false;
 396     }
 397
 398   errno = 0;
 399   dp = readdir_ignoring_dot_and_dotdot (dirp);
 400   saved_errno = errno;
 401   closedir (dirp);
 402   if (dp != NULL)
 403     return false;
 404   return saved_errno == 0 ? true : false;
 405 }
 406
 407 /* Factor out some of the common --help and --version processing code.  */
 408
 409 /* These enum values cannot possibly conflict with the option values
 410    ordinarily used by commands, including CHAR_MAX + 1, etc.  Avoid
 411    CHAR_MIN - 1, as it may equal -1, the getopt end-of-options value.  */
 412 enum
 413 {
 414   GETOPT_HELP_CHAR = (CHAR_MIN - 2),
 415   GETOPT_VERSION_CHAR = (CHAR_MIN - 3)
 416 };
 417
 418 #define GETOPT_HELP_OPTION_DECL \
 419   "help", no_argument, NULL, GETOPT_HELP_CHAR
 420 #define GETOPT_VERSION_OPTION_DECL \
 421   "version", no_argument, NULL, GETOPT_VERSION_CHAR
 422 #define GETOPT_SELINUX_CONTEXT_OPTION_DECL \
 423   "context", required_argument, NULL, 'Z'
 424
 425 #define case_GETOPT_HELP_CHAR                   \
 426   case GETOPT_HELP_CHAR:                        \
 427     usage (EXIT_SUCCESS);                       \
 428     break;
 429
 430 /* Program_name must be a literal string.
 431    Usually it is just PROGRAM_NAME.  */
 432 #define USAGE_BUILTIN_WARNING \
 433   _("\n" \
 434 "NOTE: your shell may have its own version of %s, which usually supersedes\n" \
 435 "the version described here.  Please refer to your shell's documentation\n" \
 436 "for details about the options it supports.\n")
 437
 438 #define HELP_OPTION_DESCRIPTION \
 439   _("      --help     display this help and exit\n")
 440 #define VERSION_OPTION_DESCRIPTION \
 441   _("      --version  output version information and exit\n")
 442
 443 #include "closein.h"
 444 #include "closeout.h"
 445
 446 #define emit_bug_reporting_address unused__emit_bug_reporting_address
 447 #include "version-etc.h"
 448 #undef emit_bug_reporting_address
 449
 450 #include "propername.h"
 451 /* Define away proper_name (leaving proper_name_utf8, which affects far
 452    fewer programs), since it's not worth the cost of adding ~17KB to
 453    the x86_64 text size of every single program.  This avoids a 40%
 454    (almost ~2MB) increase in the on-disk space utilization for the set
 455    of the 100 binaries. */
 456 #define proper_name(x) (x)
 457
 458 #include "progname.h"
 459
 460 #define case_GETOPT_VERSION_CHAR(Program_name, Authors)                 \
 461   case GETOPT_VERSION_CHAR:                                             \
 462     version_etc (stdout, Program_name, PACKAGE_NAME, Version, Authors,  \
 463                  (char *) NULL);                                        \
 464     exit (EXIT_SUCCESS);                                                \
 465     break;
 466
 467 #ifndef MAX
 468 # define MAX(a, b) ((a) > (b) ? (a) : (b))
 469 #endif
 470
 471 #ifndef MIN
 472 # define MIN(a,b) (((a) < (b)) ? (a) : (b))
 473 #endif
 474
 475 #include "intprops.h"
 476
 477 #ifndef SSIZE_MAX
 478 # define SSIZE_MAX TYPE_MAXIMUM (ssize_t)
 479 #endif
 480
 481 #ifndef OFF_T_MIN
 482 # define OFF_T_MIN TYPE_MINIMUM (off_t)
 483 #endif
 484
 485 #ifndef OFF_T_MAX
 486 # define OFF_T_MAX TYPE_MAXIMUM (off_t)
 487 #endif
 488
 489 #ifndef UID_T_MAX
 490 # define UID_T_MAX TYPE_MAXIMUM (uid_t)
 491 #endif
 492
 493 #ifndef GID_T_MAX
 494 # define GID_T_MAX TYPE_MAXIMUM (gid_t)
 495 #endif
 496
 497 #ifndef PID_T_MAX
 498 # define PID_T_MAX TYPE_MAXIMUM (pid_t)
 499 #endif
 500
 501 /* Use this to suppress gcc's `...may be used before initialized' warnings. */
 502 #ifdef lint
 503 # define IF_LINT(Code) Code
 504 #else
 505 # define IF_LINT(Code) /* empty */
 506 #endif
 507
 508 /* With -Dlint, avoid warnings from gcc about code like mbstate_t m = {0,};
 509    by wasting space on a static variable of the same type, that is thus
 510    guaranteed to be initialized to 0, and use that on the RHS.  */
 511 #define DZA_CONCAT0(x,y) x ## y
 512 #define DZA_CONCAT(x,y) DZA_CONCAT0 (x, y)
 513 #ifdef lint
 514 # define DECLARE_ZEROED_AGGREGATE(Type, Var) \
 515    static Type DZA_CONCAT (s0_, __LINE__); Type Var = DZA_CONCAT (s0_, __LINE__)
 516 #else
 517 # define DECLARE_ZEROED_AGGREGATE(Type, Var) \
 518   Type Var = { 0, }
 519 #endif
 520
 521 #ifndef __attribute__
 522 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8)
 523 #  define __attribute__(x) /* empty */
 524 # endif
 525 #endif
 526
 527 #ifndef ATTRIBUTE_NORETURN
 528 # define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
 529 #endif
 530
 531 #ifndef ATTRIBUTE_UNUSED
 532 # define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
 533 #endif
 534
 535 #if defined strdupa
 536 # define ASSIGN_STRDUPA(DEST, S)                \
 537   do { DEST = strdupa (S); } while (0)
 538 #else
 539 # define ASSIGN_STRDUPA(DEST, S)                \
 540   do                                            \
 541     {                                           \
 542       const char *s_ = (S);                     \
 543       size_t len_ = strlen (s_) + 1;            \
 544       char *tmp_dest_ = alloca (len_);          \
 545       DEST = memcpy (tmp_dest_, s_, len_);      \
 546     }                                           \
 547   while (0)
 548 #endif
 549
 550 #ifndef EOVERFLOW
 551 # define EOVERFLOW EINVAL
 552 #endif
 553
 554 #if ! HAVE_SYNC
 555 # define sync() /* empty */
 556 #endif
 557
 558 /* Compute the greatest common divisor of U and V using Euclid's
 559    algorithm.  U and V must be nonzero.  */
 560
 561 static inline size_t
 562 gcd (size_t u, size_t v)
 563 {
 564   do
 565     {
 566       size_t t = u % v;
 567       u = v;
 568       v = t;
 569     }
 570   while (v);
 571
 572   return u;
 573 }
 574
 575 /* Compute the least common multiple of U and V.  U and V must be
 576    nonzero.  There is no overflow checking, so callers should not
 577    specify outlandish sizes.  */
 578
 579 static inline size_t
 580 lcm (size_t u, size_t v)
 581 {
 582   return u * (v / gcd (u, v));
 583 }
 584
 585 /* Return PTR, aligned upward to the next multiple of ALIGNMENT.
 586    ALIGNMENT must be nonzero.  The caller must arrange for ((char *)
 587    PTR) through ((char *) PTR + ALIGNMENT - 1) to be addressable
 588    locations.  */
 589
 590 static inline void *
 591 ptr_align (void const *ptr, size_t alignment)
 592 {
 593   char const *p0 = ptr;
 594   char const *p1 = p0 + alignment - 1;
 595   return (void *) (p1 - (size_t) p1 % alignment);
 596 }
 597
 598 /* If 10*Accum + Digit_val is larger than the maximum value for Type,
 599    then don't update Accum and return false to indicate it would
 600    overflow.  Otherwise, set Accum to that new value and return true.
 601    Verify at compile-time that Type is Accum's type, and that Type is
 602    unsigned.  Accum must be an object, so that we can take its
 603    address.  Accum and Digit_val may be evaluated multiple times.
 604
 605    The "Added check" below is not strictly required, but it causes GCC
 606    to return a nonzero exit status instead of merely a warning
 607    diagnostic, and that is more useful.  */
 608
 609 #define DECIMAL_DIGIT_ACCUMULATE(Accum, Digit_val, Type)                \
 610   (                                                                     \
 611    (void) (&(Accum) == (Type *) NULL),  /* The type matches.  */        \
 612    (void) verify_true (! TYPE_SIGNED (Type)), /* The type is unsigned.  */ \
 613    (void) verify_true (sizeof (Accum) == sizeof (Type)), /* Added check.  */ \
 614    (((Type) -1 / 10 < (Accum)                                           \
 615      || (Type) ((Accum) * 10 + (Digit_val)) < (Accum))                  \
 616     ? false : (((Accum) = (Accum) * 10 + (Digit_val)), true))           \
 617   )
 618
 619 #include "hard-locale.h"
 620 static inline void
 621 emit_bug_reporting_address (void)
 622 {
 623   printf (_("\nReport %s bugs to %s\n"), last_component (program_name),
 624           PACKAGE_BUGREPORT);
 625   /* FIXME 2010: use AC_PACKAGE_URL once we require autoconf-2.64 */
 626   printf (_("%s home page: <http://www.gnu.org/software/%s/>\n"),
 627           PACKAGE_NAME, PACKAGE);
 628   fputs (_("General help using GNU software: <http://www.gnu.org/gethelp/>\n"),
 629          stdout);
 630
 631   if (hard_locale (LC_MESSAGES))
 632     {
 633       /* TRANSLATORS: Replace LANG_CODE in this URL with your language code
 634          <http://translationproject.org/team/LANG_CODE.html> to form one of
 635          the URLs at http://translationproject.org/team/.  Otherwise, replace
 636          the entire URL with your translation team's email address.  */
 637       printf (_("Report %s translation bugs to "
 638                 "<http://translationproject.org/team/>\n"),
 639                 last_component (program_name));
 640     }
 641 }
 642
 643 #include "inttostr.h"
 644
 645 static inline char *
 646 timetostr (time_t t, char *buf)
 647 {
 648   return (TYPE_SIGNED (time_t)
 649           ? imaxtostr (t, buf)
 650           : umaxtostr (t, buf));
 651 }
 652
 653 static inline char *
 654 bad_cast (char const *s)
 655 {
 656   return (char *) s;
 657 }
 658
 659 /* As of Mar 2009, 32KiB is determined to be the minimium
 660    blksize to best minimize system call overhead.
 661    This can be tested with this script with the results
 662    shown for a 1.7GHz pentium-m with 2GB of 400MHz DDR2 RAM:
 663
 664    for i in $(seq 0 10); do
 665      size=$((8*1024**3)) #ensure this is big enough
 666      bs=$((1024*2**$i))
 667      printf "%7s=" $bs
 668      dd bs=$bs if=/dev/zero of=/dev/null count=$(($size/$bs)) 2>&1 |
 669      sed -n 's/.* \([0-9.]* [GM]B\/s\)/\1/p'
 670    done
 671
 672       1024=734 MB/s
 673       2048=1.3 GB/s
 674       4096=2.4 GB/s
 675       8192=3.5 GB/s
 676      16384=3.9 GB/s
 677      32768=5.2 GB/s
 678      65536=5.3 GB/s
 679     131072=5.5 GB/s
 680     262144=5.7 GB/s
 681     524288=5.7 GB/s
 682    1048576=5.8 GB/s
 683
 684    Note that this is to minimize system call overhead.
 685    Other values may be appropriate to minimize file system
 686    or disk overhead.  For example on my current linux system
 687    the readahead setting is 128KiB which was read using:
 688
 689    file="."
 690    device=$(df -P --local "$file" | tail -n1 | cut -d' ' -f1)
 691    echo $(( $(blockdev --getra $device) * 512 ))
 692
 693    However there isn't a portable way to get the above.
 694    In the future we could use the above method if available
 695    and default to io_blksize() if not.
 696  */
 697 enum { IO_BUFSIZE = 32*1024 };
 698 static inline size_t
 699 io_blksize (struct stat sb)
 700 {
 701   return MAX (IO_BUFSIZE, ST_BLKSIZE (sb));
 702 }
 703
 704 void usage (int status) ATTRIBUTE_NORETURN;