src/system.h

   1 /* system-dependent definitions for coreutils
   2    Copyright (C) 1989, 1991-2006 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 2, or (at your option)
   7    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, write to the Free Software Foundation,
  16    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  17
  18 #include <alloca.h>
  19
  20 /* Include sys/types.h before this file.  */
  21
  22 #if 2 <= __GLIBC__ && 2 <= __GLIBC_MINOR__
  23 # if ! defined _SYS_TYPES_H
  24 you must include <sys/types.h> before including this file
  25 # endif
  26 #endif
  27
  28 #include <sys/stat.h>
  29
  30 #if !defined HAVE_MKFIFO
  31 # define mkfifo(name, mode) mknod (name, (mode) | S_IFIFO, 0)
  32 #endif
  33
  34 #if HAVE_SYS_PARAM_H
  35 # include <sys/param.h>
  36 #endif
  37
  38 #include <unistd.h>
  39
  40 #ifndef STDIN_FILENO
  41 # define STDIN_FILENO 0
  42 #endif
  43
  44 #ifndef STDOUT_FILENO
  45 # define STDOUT_FILENO 1
  46 #endif
  47
  48 #ifndef STDERR_FILENO
  49 # define STDERR_FILENO 2
  50 #endif
  51
  52
  53 /* limits.h must come before pathmax.h because limits.h on some systems
  54    undefs PATH_MAX, whereas pathmax.h sets PATH_MAX.  */
  55 #include <limits.h>
  56
  57 #include "pathmax.h"
  58
  59 #include "configmake.h"
  60
  61 #if TIME_WITH_SYS_TIME
  62 # include <sys/time.h>
  63 # include <time.h>
  64 #else
  65 # if HAVE_SYS_TIME_H
  66 #  include <sys/time.h>
  67 # else
  68 #  include <time.h>
  69 # endif
  70 #endif
  71
  72 /* Since major is a function on SVR4, we can't use `ifndef major'.  */
  73 #if MAJOR_IN_MKDEV
  74 # include <sys/mkdev.h>
  75 # define HAVE_MAJOR
  76 #endif
  77 #if MAJOR_IN_SYSMACROS
  78 # include <sys/sysmacros.h>
  79 # define HAVE_MAJOR
  80 #endif
  81 #ifdef major                    /* Might be defined in sys/types.h.  */
  82 # define HAVE_MAJOR
  83 #endif
  84
  85 #ifndef HAVE_MAJOR
  86 # define major(dev)  (((dev) >> 8) & 0xff)
  87 # define minor(dev)  ((dev) & 0xff)
  88 # define makedev(maj, min)  (((maj) << 8) | (min))
  89 #endif
  90 #undef HAVE_MAJOR
  91
  92 #if ! defined makedev && defined mkdev
  93 # define makedev(maj, min)  mkdev (maj, min)
  94 #endif
  95
  96 /* Don't use bcopy!  Use memmove if source and destination may overlap,
  97    memcpy otherwise.  */
  98
  99 #include <string.h>
 100 #include "mempcpy.h"
 101 #include "memrchr.h"
 102 #include "stpcpy.h"
 103 #include "strpbrk.h"
 104
 105 #include <errno.h>
 106
 107 /* Some systems don't define the following symbols.  */
 108 #ifndef EDQUOT
 109 # define EDQUOT (-1)
 110 #endif
 111 #ifndef EISDIR
 112 # define EISDIR (-1)
 113 #endif
 114 #ifndef ENOSYS
 115 # define ENOSYS (-1)
 116 #endif
 117
 118 #include <stdbool.h>
 119 #include <stdlib.h>
 120
 121 /* The following test is to work around the gross typo in
 122    systems like Sony NEWS-OS Release 4.0C, whereby EXIT_FAILURE
 123    is defined to 0, not 1.  */
 124 #if !EXIT_FAILURE
 125 # undef EXIT_FAILURE
 126 # define EXIT_FAILURE 1
 127 #endif
 128
 129 #ifndef EXIT_SUCCESS
 130 # define EXIT_SUCCESS 0
 131 #endif
 132
 133 /* Exit statuses for programs like 'env' that exec other programs.
 134    EXIT_FAILURE might not be 1, so use EXIT_FAIL in such programs.  */
 135 enum
 136 {
 137   EXIT_FAIL = 1,
 138   EXIT_CANNOT_INVOKE = 126,
 139   EXIT_ENOENT = 127
 140 };
 141
 142 #include "exitfail.h"
 143
 144 /* Set exit_failure to STATUS if that's not the default already.  */
 145 static inline void
 146 initialize_exit_failure (int status)
 147 {
 148   if (status != EXIT_FAILURE)
 149     exit_failure = status;
 150 }
 151
 152 #include <fcntl.h>
 153
 154 #ifndef F_OK
 155 # define F_OK 0
 156 # define X_OK 1
 157 # define W_OK 2
 158 # define R_OK 4
 159 #endif
 160
 161 #include <dirent.h>
 162 #ifndef _D_EXACT_NAMLEN
 163 # define _D_EXACT_NAMLEN(dp) strlen ((dp)->d_name)
 164 #endif
 165
 166 enum
 167 {
 168   NOT_AN_INODE_NUMBER = 0
 169 };
 170
 171 #ifdef D_INO_IN_DIRENT
 172 # define D_INO(dp) (dp)->d_ino
 173 #else
 174 /* Some systems don't have inodes, so fake them to avoid lots of ifdefs.  */
 175 # define D_INO(dp) NOT_AN_INODE_NUMBER
 176 #endif
 177
 178 /* Get or fake the disk device blocksize.
 179    Usually defined by sys/param.h (if at all).  */
 180 #if !defined DEV_BSIZE && defined BSIZE
 181 # define DEV_BSIZE BSIZE
 182 #endif
 183 #if !defined DEV_BSIZE && defined BBSIZE /* SGI */
 184 # define DEV_BSIZE BBSIZE
 185 #endif
 186 #ifndef DEV_BSIZE
 187 # define DEV_BSIZE 4096
 188 #endif
 189
 190 /* Extract or fake data from a `struct stat'.
 191    ST_BLKSIZE: Preferred I/O blocksize for the file, in bytes.
 192    ST_NBLOCKS: Number of blocks in the file, including indirect blocks.
 193    ST_NBLOCKSIZE: Size of blocks used when calculating ST_NBLOCKS.  */
 194 #ifndef HAVE_STRUCT_STAT_ST_BLOCKS
 195 # define ST_BLKSIZE(statbuf) DEV_BSIZE
 196 # if defined _POSIX_SOURCE || !defined BSIZE /* fileblocks.c uses BSIZE.  */
 197 #  define ST_NBLOCKS(statbuf) \
 198   ((statbuf).st_size / ST_NBLOCKSIZE + ((statbuf).st_size % ST_NBLOCKSIZE != 0))
 199 # else /* !_POSIX_SOURCE && BSIZE */
 200 #  define ST_NBLOCKS(statbuf) \
 201   (S_ISREG ((statbuf).st_mode) \
 202    || S_ISDIR ((statbuf).st_mode) \
 203    ? st_blocks ((statbuf).st_size) : 0)
 204 # endif /* !_POSIX_SOURCE && BSIZE */
 205 #else /* HAVE_STRUCT_STAT_ST_BLOCKS */
 206 /* Some systems, like Sequents, return st_blksize of 0 on pipes.
 207    Also, when running `rsh hpux11-system cat any-file', cat would
 208    determine that the output stream had an st_blksize of 2147421096.
 209    Conversely st_blksize can be 2 GiB (or maybe even larger) with XFS
 210    on 64-bit hosts.  Somewhat arbitrarily, limit the `optimal' block
 211    size to SIZE_MAX / 8 + 1.  (Dividing SIZE_MAX by only 4 wouldn't
 212    suffice, since "cat" sometimes multiplies the result by 4.)  If
 213    anyone knows of a system for which this limit is too small, please
 214    report it as a bug in this code.  */
 215 # define ST_BLKSIZE(statbuf) ((0 < (statbuf).st_blksize \
 216                                && (statbuf).st_blksize <= SIZE_MAX / 8 + 1) \
 217                               ? (statbuf).st_blksize : DEV_BSIZE)
 218 # if defined hpux || defined __hpux__ || defined __hpux
 219 /* HP-UX counts st_blocks in 1024-byte units.
 220    This loses when mixing HP-UX and BSD file systems with NFS.  */
 221 #  define ST_NBLOCKSIZE 1024
 222 # else /* !hpux */
 223 #  if defined _AIX && defined _I386
 224 /* AIX PS/2 counts st_blocks in 4K units.  */
 225 #   define ST_NBLOCKSIZE (4 * 1024)
 226 #  else /* not AIX PS/2 */
 227 #   if defined _CRAY
 228 #    define ST_NBLOCKS(statbuf) \
 229   (S_ISREG ((statbuf).st_mode) \
 230    || S_ISDIR ((statbuf).st_mode) \
 231    ? (statbuf).st_blocks * ST_BLKSIZE(statbuf)/ST_NBLOCKSIZE : 0)
 232 #   endif /* _CRAY */
 233 #  endif /* not AIX PS/2 */
 234 # endif /* !hpux */
 235 #endif /* HAVE_STRUCT_STAT_ST_BLOCKS */
 236
 237 #ifndef ST_NBLOCKS
 238 # define ST_NBLOCKS(statbuf) ((statbuf).st_blocks)
 239 #endif
 240
 241 #ifndef ST_NBLOCKSIZE
 242 # ifdef S_BLKSIZE
 243 #  define ST_NBLOCKSIZE S_BLKSIZE
 244 # else
 245 #  define ST_NBLOCKSIZE 512
 246 # endif
 247 #endif
 248
 249 /* Redirection and wildcarding when done by the utility itself.
 250    Generally a noop, but used in particular for native VMS. */
 251 #ifndef initialize_main
 252 # define initialize_main(ac, av)
 253 #endif
 254
 255 #include "stat-macros.h"
 256
 257 #include "timespec.h"
 258
 259 #include <inttypes.h>
 260
 261 #include <ctype.h>
 262
 263 #if ! (defined isblank || HAVE_DECL_ISBLANK)
 264 # define isblank(c) ((c) == ' ' || (c) == '\t')
 265 #endif
 266
 267 /* ISDIGIT differs from isdigit, as follows:
 268    - Its arg may be any int or unsigned int; it need not be an unsigned char
 269      or EOF.
 270    - It's typically faster.
 271    POSIX says that only '0' through '9' are digits.  Prefer ISDIGIT to
 272    isdigit unless it's important to use the locale's definition
 273    of `digit' even when the host does not conform to POSIX.  */
 274 #define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9)
 275
 276 /* Convert a possibly-signed character to an unsigned character.  This is
 277    a bit safer than casting to unsigned char, since it catches some type
 278    errors that the cast doesn't.  */
 279 static inline unsigned char to_uchar (char ch) { return ch; }
 280
 281 #include <locale.h>
 282
 283 /* Take care of NLS matters.  */
 284
 285 #include "gettext.h"
 286 #if ! ENABLE_NLS
 287 # undef textdomain
 288 # define textdomain(Domainname) /* empty */
 289 # undef bindtextdomain
 290 # define bindtextdomain(Domainname, Dirname) /* empty */
 291 #endif
 292
 293 #define _(msgid) gettext (msgid)
 294 #define N_(msgid) msgid
 295
 296 /* Return a value that pluralizes the same way that N does, in all
 297    languages we know of.  */
 298 static inline unsigned long int
 299 select_plural (uintmax_t n)
 300 {
 301   /* Reduce by a power of ten, but keep it away from zero.  The
 302      gettext manual says 1000000 should be safe.  */
 303   enum { PLURAL_REDUCER = 1000000 };
 304   return (n <= ULONG_MAX ? n : n % PLURAL_REDUCER + PLURAL_REDUCER);
 305 }
 306
 307 #define STREQ(a, b) (strcmp ((a), (b)) == 0)
 308
 309 #if !HAVE_DECL_FREE
 310 void free ();
 311 #endif
 312
 313 #if !HAVE_DECL_MALLOC
 314 char *malloc ();
 315 #endif
 316
 317 #if !HAVE_DECL_MEMCHR
 318 char *memchr ();
 319 #endif
 320
 321 #if !HAVE_DECL_REALLOC
 322 char *realloc ();
 323 #endif
 324
 325 #if !HAVE_DECL_GETENV
 326 char *getenv ();
 327 #endif
 328
 329 #if !HAVE_DECL_LSEEK
 330 off_t lseek ();
 331 #endif
 332
 333 #if !HAVE_DECL_GETLOGIN
 334 char *getlogin ();
 335 #endif
 336
 337 #if !HAVE_DECL_TTYNAME
 338 char *ttyname ();
 339 #endif
 340
 341 #if !HAVE_DECL_GETEUID
 342 uid_t geteuid ();
 343 #endif
 344
 345 #if !HAVE_DECL_GETPWUID
 346 struct passwd *getpwuid ();
 347 #endif
 348
 349 #if !HAVE_DECL_GETGRGID
 350 struct group *getgrgid ();
 351 #endif
 352
 353 #if !HAVE_DECL_GETUID
 354 uid_t getuid ();
 355 #endif
 356
 357 #include "xalloc.h"
 358 #include "verify.h"
 359
 360 /* This is simply a shorthand for the common case in which
 361    the third argument to x2nrealloc would be `sizeof *(P)'.
 362    Ensure that sizeof *(P) is *not* 1.  In that case, it'd be
 363    better to use X2REALLOC, although not strictly necessary.  */
 364 #define X2NREALLOC(P, PN) ((void) verify_true (sizeof *(P) != 1), \
 365                            x2nrealloc (P, PN, sizeof *(P)))
 366
 367 /* Using x2realloc (when appropriate) usually makes your code more
 368    readable than using x2nrealloc, but it also makes it so your
 369    code will malfunction if sizeof *(P) ever becomes 2 or greater.
 370    So use this macro instead of using x2realloc directly.  */
 371 #define X2REALLOC(P, PN) ((void) verify_true (sizeof *(P) == 1), \
 372                           x2realloc (P, PN))
 373
 374 #include "unlocked-io.h"
 375 #include "same-inode.h"
 376
 377 #include "dirname.h"
 378
 379 static inline bool
 380 dot_or_dotdot (char const *file_name)
 381 {
 382   if (file_name[0] == '.')
 383     {
 384       char sep = file_name[(file_name[1] == '.') + 1];
 385       return (! sep || ISSLASH (sep));
 386     }
 387   else
 388     return false;
 389 }
 390
 391 /* A wrapper for readdir so that callers don't see entries for `.' or `..'.  */
 392 static inline struct dirent const *
 393 readdir_ignoring_dot_and_dotdot (DIR *dirp)
 394 {
 395   while (1)
 396     {
 397       struct dirent const *dp = readdir (dirp);
 398       if (dp == NULL || ! dot_or_dotdot (dp->d_name))
 399         return dp;
 400     }
 401 }
 402
 403 #if SETVBUF_REVERSED
 404 # define SETVBUF(Stream, Buffer, Type, Size) \
 405     setvbuf (Stream, Type, Buffer, Size)
 406 #else
 407 # define SETVBUF(Stream, Buffer, Type, Size) \
 408     setvbuf (Stream, Buffer, Type, Size)
 409 #endif
 410
 411 /* Factor out some of the common --help and --version processing code.  */
 412
 413 /* These enum values cannot possibly conflict with the option values
 414    ordinarily used by commands, including CHAR_MAX + 1, etc.  Avoid
 415    CHAR_MIN - 1, as it may equal -1, the getopt end-of-options value.  */
 416 enum
 417 {
 418   GETOPT_HELP_CHAR = (CHAR_MIN - 2),
 419   GETOPT_VERSION_CHAR = (CHAR_MIN - 3)
 420 };
 421
 422 #define GETOPT_HELP_OPTION_DECL \
 423   "help", no_argument, NULL, GETOPT_HELP_CHAR
 424 #define GETOPT_VERSION_OPTION_DECL \
 425   "version", no_argument, NULL, GETOPT_VERSION_CHAR
 426
 427 #define case_GETOPT_HELP_CHAR                   \
 428   case GETOPT_HELP_CHAR:                        \
 429     usage (EXIT_SUCCESS);                       \
 430     break;
 431
 432 /* Program_name must be a literal string.
 433    Usually it is just PROGRAM_NAME.  */
 434 #define USAGE_BUILTIN_WARNING \
 435   _("\n" \
 436 "NOTE: your shell may have its own version of %s, which usually supersedes\n" \
 437 "the version described here.  Please refer to your shell's documentation\n" \
 438 "for details about the options it supports.\n")
 439
 440 #define HELP_OPTION_DESCRIPTION \
 441   _("      --help     display this help and exit\n")
 442 #define VERSION_OPTION_DESCRIPTION \
 443   _("      --version  output version information and exit\n")
 444
 445 #include "closeout.h"
 446 #include "version-etc.h"
 447
 448 #define case_GETOPT_VERSION_CHAR(Program_name, Authors)                 \
 449   case GETOPT_VERSION_CHAR:                                             \
 450     version_etc (stdout, Program_name, GNU_PACKAGE, VERSION, Authors,   \
 451                  (char *) NULL);                                        \
 452     exit (EXIT_SUCCESS);                                                \
 453     break;
 454
 455 #ifndef MAX
 456 # define MAX(a, b) ((a) > (b) ? (a) : (b))
 457 #endif
 458
 459 #ifndef MIN
 460 # define MIN(a,b) (((a) < (b)) ? (a) : (b))
 461 #endif
 462
 463 #include "intprops.h"
 464
 465 #ifndef SSIZE_MAX
 466 # define SSIZE_MAX TYPE_MAXIMUM (ssize_t)
 467 #endif
 468
 469 #ifndef OFF_T_MIN
 470 # define OFF_T_MIN TYPE_MINIMUM (off_t)
 471 #endif
 472
 473 #ifndef OFF_T_MAX
 474 # define OFF_T_MAX TYPE_MAXIMUM (off_t)
 475 #endif
 476
 477 #ifndef UID_T_MAX
 478 # define UID_T_MAX TYPE_MAXIMUM (uid_t)
 479 #endif
 480
 481 #ifndef GID_T_MAX
 482 # define GID_T_MAX TYPE_MAXIMUM (gid_t)
 483 #endif
 484
 485 #ifndef PID_T_MAX
 486 # define PID_T_MAX TYPE_MAXIMUM (pid_t)
 487 #endif
 488
 489 /* Use this to suppress gcc's `...may be used before initialized' warnings. */
 490 #ifdef lint
 491 # define IF_LINT(Code) Code
 492 #else
 493 # define IF_LINT(Code) /* empty */
 494 #endif
 495
 496 #ifndef __attribute__
 497 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
 498 #  define __attribute__(x) /* empty */
 499 # endif
 500 #endif
 501
 502 #ifndef ATTRIBUTE_NORETURN
 503 # define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
 504 #endif
 505
 506 #ifndef ATTRIBUTE_UNUSED
 507 # define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
 508 #endif
 509
 510 #if defined strdupa
 511 # define ASSIGN_STRDUPA(DEST, S)                \
 512   do { DEST = strdupa (S); } while (0)
 513 #else
 514 # define ASSIGN_STRDUPA(DEST, S)                \
 515   do                                            \
 516     {                                           \
 517       const char *s_ = (S);                     \
 518       size_t len_ = strlen (s_) + 1;            \
 519       char *tmp_dest_ = alloca (len_);          \
 520       DEST = memcpy (tmp_dest_, (s_), len_);    \
 521     }                                           \
 522   while (0)
 523 #endif
 524
 525 #ifndef EOVERFLOW
 526 # define EOVERFLOW EINVAL
 527 #endif
 528
 529 #if ! HAVE_FSEEKO && ! defined fseeko
 530 # define fseeko(s, o, w) ((o) == (long int) (o)         \
 531                           ? fseek (s, o, w)             \
 532                           : (errno = EOVERFLOW, -1))
 533 #endif
 534
 535 #if ! HAVE_SYNC
 536 # define sync() /* empty */
 537 #endif
 538
 539 /* Compute the greatest common divisor of U and V using Euclid's
 540    algorithm.  U and V must be nonzero.  */
 541
 542 static inline size_t
 543 gcd (size_t u, size_t v)
 544 {
 545   do
 546     {
 547       size_t t = u % v;
 548       u = v;
 549       v = t;
 550     }
 551   while (v);
 552
 553   return u;
 554 }
 555
 556 /* Compute the least common multiple of U and V.  U and V must be
 557    nonzero.  There is no overflow checking, so callers should not
 558    specify outlandish sizes.  */
 559
 560 static inline size_t
 561 lcm (size_t u, size_t v)
 562 {
 563   return u * (v / gcd (u, v));
 564 }
 565
 566 /* Return PTR, aligned upward to the next multiple of ALIGNMENT.
 567    ALIGNMENT must be nonzero.  The caller must arrange for ((char *)
 568    PTR) through ((char *) PTR + ALIGNMENT - 1) to be addressable
 569    locations.  */
 570
 571 static inline void *
 572 ptr_align (void const *ptr, size_t alignment)
 573 {
 574   char const *p0 = ptr;
 575   char const *p1 = p0 + alignment - 1;
 576   return (void *) (p1 - (size_t) p1 % alignment);
 577 }
 578
 579 /* If 10*Accum + Digit_val is larger than the maximum value for Type,
 580    then don't update Accum and return false to indicate it would
 581    overflow.  Otherwise, set Accum to that new value and return true.
 582    Verify at compile-time that Type is Accum's type, and that Type is
 583    unsigned.  Accum must be an object, so that we can take its
 584    address.  Accum and Digit_val may be evaluated multiple times.
 585
 586    The "Added check" below is not strictly required, but it causes GCC
 587    to return a nonzero exit status instead of merely a warning
 588    diagnostic, and that is more useful.  */
 589
 590 #define DECIMAL_DIGIT_ACCUMULATE(Accum, Digit_val, Type)                \
 591   (                                                                     \
 592    (void) (&(Accum) == (Type *) NULL),  /* The type matches.  */        \
 593    (void) verify_true (! TYPE_SIGNED (Type)), /* The type is unsigned.  */ \
 594    (void) verify_true (sizeof (Accum) == sizeof (Type)), /* Added check.  */ \
 595    (((Type) -1 / 10 < (Accum)                                           \
 596      || (Type) ((Accum) * 10 + (Digit_val)) < (Accum))                  \
 597     ? false : (((Accum) = (Accum) * 10 + (Digit_val)), true))           \
 598   )