src/system.h

   1 /* system-dependent definitions for coreutils
   2    Copyright (C) 1989-2024 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 <https://www.gnu.org/licenses/>.  */
  16
  17 /* Include this file _after_ system headers if possible.  */
  18
  19 #include <attribute.h>
  20
  21 #include <alloca.h>
  22
  23 #include <sys/stat.h>
  24
  25 /* Commonly used file permission combination.  */
  26 #define MODE_RW_UGO (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH)
  27
  28 #if HAVE_SYS_PARAM_H
  29 # include <sys/param.h>
  30 #endif
  31
  32 #include <unistd.h>
  33
  34 #include <limits.h>
  35
  36 #include "pathmax.h"
  37 #ifndef PATH_MAX
  38 # define PATH_MAX 8192
  39 #endif
  40
  41 #include "configmake.h"
  42
  43 #include <sys/time.h>
  44 #include <time.h>
  45
  46 /* Since major is a function on SVR4, we can't use 'ifndef major'.  */
  47 #if MAJOR_IN_MKDEV
  48 # include <sys/mkdev.h>
  49 # define HAVE_MAJOR
  50 #endif
  51 #if MAJOR_IN_SYSMACROS
  52 # include <sys/sysmacros.h>
  53 # define HAVE_MAJOR
  54 #endif
  55 #ifdef major                    /* Might be defined in sys/types.h.  */
  56 # define HAVE_MAJOR
  57 #endif
  58
  59 #ifndef HAVE_MAJOR
  60 # define major(dev)  (((dev) >> 8) & 0xff)
  61 # define minor(dev)  ((dev) & 0xff)
  62 # define makedev(maj, min)  (((maj) << 8) | (min))
  63 #endif
  64 #undef HAVE_MAJOR
  65
  66 #if ! defined makedev && defined mkdev
  67 # define makedev(maj, min)  mkdev (maj, min)
  68 #endif
  69
  70 #include <stdckdint.h>
  71 #include <stddef.h>
  72 #include <string.h>
  73 #include <errno.h>
  74
  75 /* Some systems don't define this; POSIX mentions it but says it is
  76    obsolete.  gnulib defines it, but only on native Windows systems,
  77    and there only because MSVC 10 does.  */
  78 #ifndef ENODATA
  79 # define ENODATA (-1)
  80 #endif
  81
  82 #include <stdlib.h>
  83 #include "version.h"
  84
  85 /* Exit statuses for programs like 'env' that exec other programs.  */
  86 enum
  87 {
  88   EXIT_TIMEDOUT = 124, /* Time expired before child completed.  */
  89   EXIT_CANCELED = 125, /* Internal error prior to exec attempt.  */
  90   EXIT_CANNOT_INVOKE = 126, /* Program located, but not usable.  */
  91   EXIT_ENOENT = 127 /* Could not find program to exec.  */
  92 };
  93
  94 #include "exitfail.h"
  95
  96 /* Set exit_failure to STATUS if that's not the default already.  */
  97 static inline void
  98 initialize_exit_failure (int status)
  99 {
 100   if (status != EXIT_FAILURE)
 101     exit_failure = status;
 102 }
 103
 104 #include <fcntl.h>
 105 #ifdef O_PATH
 106 enum { O_PATHSEARCH = O_PATH };
 107 #else
 108 enum { O_PATHSEARCH = O_SEARCH };
 109 #endif
 110
 111 #include <dirent.h>
 112 #ifndef _D_EXACT_NAMLEN
 113 # define _D_EXACT_NAMLEN(dp) strlen ((dp)->d_name)
 114 #endif
 115
 116 enum
 117 {
 118   NOT_AN_INODE_NUMBER = 0
 119 };
 120
 121 #ifdef D_INO_IN_DIRENT
 122 # define D_INO(dp) (dp)->d_ino
 123 #else
 124 /* Some systems don't have inodes, so fake them to avoid lots of ifdefs.  */
 125 # define D_INO(dp) NOT_AN_INODE_NUMBER
 126 #endif
 127
 128 /* include here for SIZE_MAX.  */
 129 #include <inttypes.h>
 130
 131 /* Redirection and wildcarding when done by the utility itself.
 132    Generally a noop, but used in particular for OS/2.  */
 133 #ifndef initialize_main
 134 # ifndef __OS2__
 135 #  define initialize_main(ac, av)
 136 # else
 137 #  define initialize_main(ac, av) \
 138      do { _wildcard (ac, av); _response (ac, av); } while (0)
 139 # endif
 140 #endif
 141
 142 #include "stat-macros.h"
 143
 144 #include "timespec.h"
 145
 146 /* ISDIGIT differs from isdigit, as follows:
 147    - Its arg may be any int or unsigned int; it need not be an unsigned char
 148      or EOF.
 149    - It's typically faster.
 150    POSIX says that only '0' through '9' are digits.  Prefer ISDIGIT to
 151    isdigit unless it's important to use the locale's definition
 152    of 'digit' even when the host does not conform to POSIX.  */
 153 #define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9)
 154
 155 /* Convert a possibly-signed character to an unsigned character.  This is
 156    a bit safer than casting to unsigned char, since it catches some type
 157    errors that the cast doesn't.  */
 158 static inline unsigned char to_uchar (char ch) { return ch; }
 159
 160 #include <locale.h>
 161
 162 /* Take care of NLS matters.  */
 163
 164 #include "gettext.h"
 165 #if ! ENABLE_NLS
 166 # undef textdomain
 167 # define textdomain(Domainname) /* empty */
 168 # undef bindtextdomain
 169 # define bindtextdomain(Domainname, Dirname) /* empty */
 170 #endif
 171
 172 #define _(msgid) gettext (msgid)
 173 #define N_(msgid) msgid
 174
 175 /* Return a value that pluralizes the same way that N does, in all
 176    languages we know of.  */
 177 static inline unsigned long int
 178 select_plural (uintmax_t n)
 179 {
 180   /* Reduce by a power of ten, but keep it away from zero.  The
 181      gettext manual says 1000000 should be safe.  */
 182   enum { PLURAL_REDUCER = 1000000 };
 183   return (n <= ULONG_MAX ? n : n % PLURAL_REDUCER + PLURAL_REDUCER);
 184 }
 185
 186 #define STREQ(a, b) (strcmp (a, b) == 0)
 187 #define STREQ_LEN(a, b, n) (strncmp (a, b, n) == 0) /* n==-1 means unbounded */
 188 #define STRPREFIX(a, b) (strncmp (a, b, strlen (b)) == 0)
 189
 190 /* Just like strncmp, but the second argument must be a literal string
 191    and you don't specify the length;  that comes from the literal.  */
 192 #define STRNCMP_LIT(s, lit) strncmp (s, "" lit "", sizeof (lit) - 1)
 193
 194 #if !HAVE_DECL_GETLOGIN
 195 char *getlogin (void);
 196 #endif
 197
 198 #if !HAVE_DECL_TTYNAME
 199 char *ttyname (int);
 200 #endif
 201
 202 #if !HAVE_DECL_GETEUID
 203 uid_t geteuid (void);
 204 #endif
 205
 206 #if !HAVE_DECL_GETPWUID
 207 struct passwd *getpwuid (uid_t);
 208 #endif
 209
 210 #if !HAVE_DECL_GETGRGID
 211 struct group *getgrgid (gid_t);
 212 #endif
 213
 214 /* Interix has replacements for getgr{gid,nam,ent}, that don't
 215    query the domain controller for group members when not required.
 216    This speeds up the calls tremendously (<1 ms vs. >3 s). */
 217 /* To protect any system that could provide _nomembers functions
 218    other than interix, check for HAVE_SETGROUPS, as interix is
 219    one of the very few (the only?) platform that lacks it */
 220 #if ! HAVE_SETGROUPS
 221 # if HAVE_GETGRGID_NOMEMBERS
 222 #  define getgrgid(gid) getgrgid_nomembers(gid)
 223 # endif
 224 # if HAVE_GETGRNAM_NOMEMBERS
 225 #  define getgrnam(nam) getgrnam_nomembers(nam)
 226 # endif
 227 # if HAVE_GETGRENT_NOMEMBERS
 228 #  define getgrent() getgrent_nomembers()
 229 # endif
 230 #endif
 231
 232 #if !HAVE_DECL_GETUID
 233 uid_t getuid (void);
 234 #endif
 235
 236 #include "idx.h"
 237 #include "xalloc.h"
 238 #include "verify.h"
 239
 240 /* This is simply a shorthand for the common case in which
 241    the third argument to x2nrealloc would be 'sizeof *(P)'.
 242    Ensure that sizeof *(P) is *not* 1.  In that case, it'd be
 243    better to use X2REALLOC, although not strictly necessary.  */
 244 #define X2NREALLOC(P, PN) verify_expr (sizeof *(P) != 1, \
 245                                        x2nrealloc (P, PN, sizeof *(P)))
 246
 247 /* Using x2realloc (when appropriate) usually makes your code more
 248    readable than using x2nrealloc, but it also makes it so your
 249    code will malfunction if sizeof *(P) ever becomes 2 or greater.
 250    So use this macro instead of using x2realloc directly.  */
 251 #define X2REALLOC(P, PN) verify_expr (sizeof *(P) == 1, \
 252                                       x2realloc (P, PN))
 253
 254 #include "unlocked-io.h"
 255 #include "same-inode.h"
 256
 257 #include "dirname.h"
 258 #include "openat.h"
 259
 260 static inline bool
 261 dot_or_dotdot (char const *file_name)
 262 {
 263   if (file_name[0] == '.')
 264     {
 265       char sep = file_name[(file_name[1] == '.') + 1];
 266       return (! sep || ISSLASH (sep));
 267     }
 268   else
 269     return false;
 270 }
 271
 272 /* A wrapper for readdir so that callers don't see entries for '.' or '..'.  */
 273 static inline struct dirent const *
 274 readdir_ignoring_dot_and_dotdot (DIR *dirp)
 275 {
 276   while (true)
 277     {
 278       struct dirent const *dp = readdir (dirp);
 279       if (dp == nullptr || ! dot_or_dotdot (dp->d_name))
 280         return dp;
 281     }
 282 }
 283
 284 /* Return -1 if DIR is an empty directory,
 285    0 if DIR is a nonempty directory,
 286    and a positive error number if there was trouble determining
 287    whether DIR is an empty or nonempty directory.  */
 288 enum {
 289     DS_UNKNOWN = -2,
 290     DS_EMPTY = -1,
 291     DS_NONEMPTY = 0,
 292 };
 293 static inline int
 294 directory_status (int fd_cwd, char const *dir)
 295 {
 296   DIR *dirp;
 297   bool no_direntries;
 298   int saved_errno;
 299   int fd = openat (fd_cwd, dir,
 300                    (O_RDONLY | O_DIRECTORY
 301                     | O_NOCTTY | O_NOFOLLOW | O_NONBLOCK));
 302
 303   if (fd < 0)
 304     return errno;
 305
 306   dirp = fdopendir (fd);
 307   if (dirp == nullptr)
 308     {
 309       saved_errno = errno;
 310       close (fd);
 311       return saved_errno;
 312     }
 313
 314   errno = 0;
 315   no_direntries = !readdir_ignoring_dot_and_dotdot (dirp);
 316   saved_errno = errno;
 317   closedir (dirp);
 318   return no_direntries && saved_errno == 0 ? DS_EMPTY : saved_errno;
 319 }
 320
 321 /* Factor out some of the common --help and --version processing code.  */
 322
 323 /* These enum values cannot possibly conflict with the option values
 324    ordinarily used by commands, including CHAR_MAX + 1, etc.  Avoid
 325    CHAR_MIN - 1, as it may equal -1, the getopt end-of-options value.  */
 326 enum
 327 {
 328   GETOPT_HELP_CHAR = (CHAR_MIN - 2),
 329   GETOPT_VERSION_CHAR = (CHAR_MIN - 3)
 330 };
 331
 332 #define GETOPT_HELP_OPTION_DECL \
 333   "help", no_argument, nullptr, GETOPT_HELP_CHAR
 334 #define GETOPT_VERSION_OPTION_DECL \
 335   "version", no_argument, nullptr, GETOPT_VERSION_CHAR
 336 #define GETOPT_SELINUX_CONTEXT_OPTION_DECL \
 337   "context", optional_argument, nullptr, 'Z'
 338
 339 #define case_GETOPT_HELP_CHAR                   \
 340   case GETOPT_HELP_CHAR:                        \
 341     usage (EXIT_SUCCESS);                       \
 342     break;
 343
 344 /* Program_name must be a literal string.
 345    Usually it is just PROGRAM_NAME.  */
 346 #define USAGE_BUILTIN_WARNING \
 347   _("\n" \
 348 "Your shell may have its own version of %s, which usually supersedes\n" \
 349 "the version described here.  Please refer to your shell's documentation\n" \
 350 "for details about the options it supports.\n")
 351
 352 #define HELP_OPTION_DESCRIPTION \
 353   _("      --help        display this help and exit\n")
 354 #define VERSION_OPTION_DESCRIPTION \
 355   _("      --version     output version information and exit\n")
 356
 357 #include "closein.h"
 358 #include "closeout.h"
 359
 360 #define emit_bug_reporting_address unused__emit_bug_reporting_address
 361 #include "version-etc.h"
 362 #undef emit_bug_reporting_address
 363
 364 #include "propername.h"
 365 /* Define away proper_name, since it's not worth the cost of adding ~17KB to
 366    the x86_64 text size of every single program.  This avoids a 40%
 367    (almost ~2MB) increase in the file system space utilization for the set
 368    of the 100 binaries. */
 369 #define proper_name(x) proper_name_lite (x, x)
 370
 371 #include "progname.h"
 372
 373 #define case_GETOPT_VERSION_CHAR(Program_name, Authors)                 \
 374   case GETOPT_VERSION_CHAR:                                             \
 375     version_etc (stdout, Program_name, PACKAGE_NAME, Version, Authors,  \
 376                  (char *) nullptr);                                     \
 377     exit (EXIT_SUCCESS);                                                \
 378     break;
 379
 380 #include "minmax.h"
 381 #include "intprops.h"
 382
 383 #ifndef SSIZE_MAX
 384 # define SSIZE_MAX TYPE_MAXIMUM (ssize_t)
 385 #endif
 386
 387 #ifndef OFF_T_MIN
 388 # define OFF_T_MIN TYPE_MINIMUM (off_t)
 389 #endif
 390
 391 #ifndef OFF_T_MAX
 392 # define OFF_T_MAX TYPE_MAXIMUM (off_t)
 393 #endif
 394
 395 #ifndef UID_T_MAX
 396 # define UID_T_MAX TYPE_MAXIMUM (uid_t)
 397 #endif
 398
 399 #ifndef GID_T_MAX
 400 # define GID_T_MAX TYPE_MAXIMUM (gid_t)
 401 #endif
 402
 403 #ifndef PID_T_MAX
 404 # define PID_T_MAX TYPE_MAXIMUM (pid_t)
 405 #endif
 406
 407 /* Use this to suppress gcc warnings.  */
 408 #ifdef lint
 409 # define IF_LINT(Code) Code
 410 #else
 411 # define IF_LINT(Code) /* empty */
 412 #endif
 413
 414 /* main_exit should be called only from the main function.  It is
 415    equivalent to 'exit'.  When checking for lint it calls 'exit', to
 416    pacify gcc -fsanitize=lint which would otherwise have false alarms
 417    for pointers in the main function's activation record.  Otherwise
 418    it simply returns from 'main'; this used to be what gcc's static
 419    checking preferred and may yet be again.  */
 420 #ifdef lint
 421 # define main_exit(status) exit (status)
 422 #else
 423 # define main_exit(status) return status
 424 #endif
 425
 426 #ifdef __GNUC__
 427 # define LIKELY(cond)    __builtin_expect ((cond), 1)
 428 # define UNLIKELY(cond)  __builtin_expect ((cond), 0)
 429 #else
 430 # define LIKELY(cond)    (cond)
 431 # define UNLIKELY(cond)  (cond)
 432 #endif
 433
 434
 435 #if defined strdupa
 436 # define ASSIGN_STRDUPA(DEST, S)                \
 437   do { DEST = strdupa (S); } while (0)
 438 #else
 439 # define ASSIGN_STRDUPA(DEST, S)                \
 440   do                                            \
 441     {                                           \
 442       char const *s_ = (S);                     \
 443       size_t len_ = strlen (s_) + 1;            \
 444       char *tmp_dest_ = alloca (len_);          \
 445       DEST = memcpy (tmp_dest_, s_, len_);      \
 446     }                                           \
 447   while (0)
 448 #endif
 449
 450 #if ! HAVE_SYNC
 451 # define sync() /* empty */
 452 #endif
 453
 454 /* Compute the greatest common divisor of U and V using Euclid's
 455    algorithm.  U and V must be nonzero.  */
 456
 457 ATTRIBUTE_CONST
 458 static inline size_t
 459 gcd (size_t u, size_t v)
 460 {
 461   do
 462     {
 463       size_t t = u % v;
 464       u = v;
 465       v = t;
 466     }
 467   while (v);
 468
 469   return u;
 470 }
 471
 472 /* Compute the least common multiple of U and V.  U and V must be
 473    nonzero.  There is no overflow checking, so callers should not
 474    specify outlandish sizes.  */
 475
 476 ATTRIBUTE_CONST
 477 static inline size_t
 478 lcm (size_t u, size_t v)
 479 {
 480   return u * (v / gcd (u, v));
 481 }
 482
 483 /* Return PTR, aligned upward to the next multiple of ALIGNMENT.
 484    ALIGNMENT must be nonzero.  The caller must arrange for ((char *)
 485    PTR) through ((char *) PTR + ALIGNMENT - 1) to be addressable
 486    locations.  */
 487
 488 static inline void *
 489 ptr_align (void const *ptr, size_t alignment)
 490 {
 491   char const *p0 = ptr;
 492   char const *p1 = p0 + alignment - 1;
 493   return (void *) (p1 - (size_t) p1 % alignment);
 494 }
 495
 496 /* Return whether the buffer consists entirely of NULs.
 497    Based on memeqzero in CCAN by Rusty Russell under CC0 (Public domain).  */
 498
 499 ATTRIBUTE_PURE
 500 static inline bool
 501 is_nul (void const *buf, size_t length)
 502 {
 503   const unsigned char *p = buf;
 504 /* Using possibly unaligned access for the first 16 bytes
 505    saves about 30-40 cycles, though it is strictly undefined behavior
 506    and so would need __attribute__ ((__no_sanitize_undefined__))
 507    to avoid -fsanitize=undefined warnings.
 508    Considering coreutils is mainly concerned with relatively
 509    large buffers, we'll just use the defined behavior.  */
 510 #if 0 && (_STRING_ARCH_unaligned || _STRING_INLINE_unaligned)
 511   unsigned long word;
 512 #else
 513   unsigned char word;
 514 #endif
 515
 516   if (! length)
 517       return true;
 518
 519   /* Check len bytes not aligned on a word.  */
 520   while (UNLIKELY (length & (sizeof word - 1)))
 521     {
 522       if (*p)
 523         return false;
 524       p++;
 525       length--;
 526       if (! length)
 527         return true;
 528    }
 529
 530   /* Check up to 16 bytes a word at a time.  */
 531   for (;;)
 532     {
 533       memcpy (&word, p, sizeof word);
 534       if (word)
 535         return false;
 536       p += sizeof word;
 537       length -= sizeof word;
 538       if (! length)
 539         return true;
 540       if (UNLIKELY (length & 15) == 0)
 541         break;
 542    }
 543
 544    /* Now we know first 16 bytes are NUL, memcmp with self.  */
 545    return memcmp (buf, p, length) == 0;
 546 }
 547
 548 /* Set Accum = 10*Accum + Digit_val and return true, where Accum is an
 549    integer object and Digit_val an integer expression.  However, if
 550    the result overflows, set Accum to an unspecified value and return
 551    false.  Accum and Digit_val may be evaluated multiple times.  */
 552
 553 #define DECIMAL_DIGIT_ACCUMULATE(Accum, Digit_val)                      \
 554   (!ckd_mul (&(Accum), Accum, 10) && !ckd_add (&(Accum), Accum, Digit_val))
 555
 556 static inline void
 557 emit_stdin_note (void)
 558 {
 559   fputs (_("\n\
 560 With no FILE, or when FILE is -, read standard input.\n\
 561 "), stdout);
 562 }
 563 static inline void
 564 emit_mandatory_arg_note (void)
 565 {
 566   fputs (_("\n\
 567 Mandatory arguments to long options are mandatory for short options too.\n\
 568 "), stdout);
 569 }
 570
 571 static inline void
 572 emit_size_note (void)
 573 {
 574   fputs (_("\n\
 575 The SIZE argument is an integer and optional unit (example: 10K is 10*1024).\n\
 576 Units are K,M,G,T,P,E,Z,Y,R,Q (powers of 1024) or KB,MB,... (powers of 1000).\n\
 577 Binary prefixes can be used, too: KiB=K, MiB=M, and so on.\n\
 578 "), stdout);
 579 }
 580
 581 static inline void
 582 emit_blocksize_note (char const *program)
 583 {
 584   printf (_("\n\
 585 Display values are in units of the first available SIZE from --block-size,\n\
 586 and the %s_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables.\n\
 587 Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set).\n\
 588 "), program);
 589 }
 590
 591 static inline void
 592 emit_update_parameters_note (void)
 593 {
 594   fputs (_("\
 595 \n\
 596 UPDATE controls which existing files in the destination are replaced.\n\
 597 'all' is the default operation when an --update option is not specified,\n\
 598 and results in all existing files in the destination being replaced.\n\
 599 'none' is like the --no-clobber option, in that no files in the\n\
 600 destination are replaced, and skipped files do not induce a failure.\n\
 601 'none-fail' also ensures no files are replaced in the destination,\n\
 602 but any skipped files are diagnosed and induce a failure.\n\
 603 'older' is the default operation when --update is specified, and results\n\
 604 in files being replaced if they're older than the corresponding source file.\n\
 605 "), stdout);
 606 }
 607
 608 static inline void
 609 emit_backup_suffix_note (void)
 610 {
 611   fputs (_("\
 612 \n\
 613 The backup suffix is '~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX.\n\
 614 The version control method may be selected via the --backup option or through\n\
 615 the VERSION_CONTROL environment variable.  Here are the values:\n\
 616 \n\
 617 "), stdout);
 618   fputs (_("\
 619   none, off       never make backups (even if --backup is given)\n\
 620   numbered, t     make numbered backups\n\
 621   existing, nil   numbered if numbered backups exist, simple otherwise\n\
 622   simple, never   always make simple backups\n\
 623 "), stdout);
 624 }
 625
 626 static inline void
 627 emit_symlink_recurse_options (char const *default_opt)
 628 {
 629       printf (_("\
 630 \n\
 631 The following options modify how a hierarchy is traversed when the -R\n\
 632 option is also specified.  If more than one is specified, only the final\n\
 633 one takes effect. %s is the default.\n\
 634 \n\
 635   -H                     if a command line argument is a symbolic link\n\
 636                          to a directory, traverse it\n\
 637   -L                     traverse every symbolic link to a directory\n\
 638                          encountered\n\
 639   -P                     do not traverse any symbolic links\n\
 640 \n\
 641 "), default_opt);
 642 }
 643
 644 static inline void
 645 emit_exec_status (char const *program)
 646 {
 647       printf (_("\n\
 648 Exit status:\n\
 649   125  if the %s command itself fails\n\
 650   126  if COMMAND is found but cannot be invoked\n\
 651   127  if COMMAND cannot be found\n\
 652   -    the exit status of COMMAND otherwise\n\
 653 "), program);
 654 }
 655
 656 static inline void
 657 emit_ancillary_info (char const *program)
 658 {
 659   struct infomap { char const *program; char const *node; } const infomap[] = {
 660     { "[", "test invocation" },
 661     { "coreutils", "Multi-call invocation" },
 662     { "sha224sum", "sha2 utilities" },
 663     { "sha256sum", "sha2 utilities" },
 664     { "sha384sum", "sha2 utilities" },
 665     { "sha512sum", "sha2 utilities" },
 666     { nullptr, nullptr }
 667   };
 668
 669   char const *node = program;
 670   struct infomap const *map_prog = infomap;
 671
 672   while (map_prog->program && ! STREQ (program, map_prog->program))
 673     map_prog++;
 674
 675   if (map_prog->node)
 676     node = map_prog->node;
 677
 678   printf (_("\n%s online help: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
 679
 680   /* Don't output this redundant message for English locales.
 681      Note we still output for 'C' so that it gets included in the man page.  */
 682   char const *lc_messages = setlocale (LC_MESSAGES, nullptr);
 683   if (lc_messages && STRNCMP_LIT (lc_messages, "en_"))
 684     {
 685       /* TRANSLATORS: Replace LANG_CODE in this URL with your language code
 686          <https://translationproject.org/team/LANG_CODE.html> to form one of
 687          the URLs at https://translationproject.org/team/.  Otherwise, replace
 688          the entire URL with your translation team's email address.  */
 689       fputs (_("Report any translation bugs to "
 690                "<https://translationproject.org/team/>\n"), stdout);
 691     }
 692   /* .htaccess on the coreutils web site maps programs to the appropriate page,
 693      however we explicitly handle "[" -> "test" here as the "[" is not
 694      recognized as part of a URL by default in terminals.  */
 695   char const *url_program = STREQ (program, "[") ? "test" : program;
 696   printf (_("Full documentation <%s%s>\n"),
 697           PACKAGE_URL, url_program);
 698   printf (_("or available locally via: info '(coreutils) %s%s'\n"),
 699           node, node == program ? " invocation" : "");
 700 }
 701
 702 /* Use a macro rather than an inline function, as this references
 703    the global program_name, which causes dynamic linking issues
 704    in libstdbuf.so on some systems where unused functions
 705    are not removed by the linker.  */
 706 #define emit_try_help() \
 707   do \
 708     { \
 709       fprintf (stderr, _("Try '%s --help' for more information.\n"), \
 710                program_name); \
 711     } \
 712   while (0)
 713
 714 #include "inttostr.h"
 715
 716 static inline char *
 717 timetostr (time_t t, char *buf)
 718 {
 719   return (TYPE_SIGNED (time_t)
 720           ? imaxtostr (t, buf)
 721           : umaxtostr (t, buf));
 722 }
 723
 724 static inline char *
 725 bad_cast (char const *s)
 726 {
 727   return (char *) s;
 728 }
 729
 730 /* Return a boolean indicating whether SB->st_size is defined.  */
 731 static inline bool
 732 usable_st_size (struct stat const *sb)
 733 {
 734   return (S_ISREG (sb->st_mode) || S_ISLNK (sb->st_mode)
 735           || S_TYPEISSHM (sb) || S_TYPEISTMO (sb));
 736 }
 737
 738 _Noreturn void usage (int status);
 739
 740 #include <error.h>
 741
 742 /* Like error(0, 0, ...), but without an implicit newline.
 743    Also a noop unless the global DEV_DEBUG is set.  */
 744 #define devmsg(...)                     \
 745   do                                    \
 746     {                                   \
 747       if (dev_debug)                    \
 748         fprintf (stderr, __VA_ARGS__);  \
 749     }                                   \
 750   while (0)
 751
 752 #define emit_cycle_warning(file_name)   \
 753   do                                    \
 754     {                                   \
 755       error (0, 0, _("\
 756 WARNING: Circular directory structure.\n\
 757 This almost certainly means that you have a corrupted file system.\n\
 758 NOTIFY YOUR SYSTEM MANAGER.\n\
 759 The following directory is part of the cycle:\n  %s\n"), \
 760              quotef (file_name));       \
 761     }                                   \
 762   while (0)
 763
 764 /* exit with a _single_ "write error" diagnostic.  */
 765
 766 static inline void
 767 write_error (void)
 768 {
 769   int saved_errno = errno;
 770   fflush (stdout);    /* Last attempt to write any buffered data.  */
 771   fpurge (stdout);    /* Ensure nothing buffered that might induce an error. */
 772   clearerr (stdout);  /* Avoid extraneous diagnostic from close_stdout.  */
 773   error (EXIT_FAILURE, saved_errno, _("write error"));
 774 }
 775
 776 /* Like stpncpy, but do ensure that the result is NUL-terminated,
 777    and do not NUL-pad out to LEN.  I.e., when strnlen (src, len) == len,
 778    this function writes a NUL byte into dest[len].  Thus, the length
 779    of the destination buffer must be at least LEN + 1.
 780    The DEST and SRC buffers must not overlap.  */
 781 static inline char *
 782 stzncpy (char *restrict dest, char const *restrict src, size_t len)
 783 {
 784   size_t i;
 785   for (i = 0; i < len && *src; i++)
 786     *dest++ = *src++;
 787   *dest = 0;
 788   return dest;
 789 }
 790
 791 #ifndef ARRAY_CARDINALITY
 792 # define ARRAY_CARDINALITY(Array) (sizeof (Array) / sizeof *(Array))
 793 #endif
 794
 795 /* Return true if ERR is ENOTSUP or EOPNOTSUPP, otherwise false.
 796    This wrapper function avoids the redundant 'or'd comparison on
 797    systems like Linux for which they have the same value.  It also
 798    avoids the gcc warning to that effect.  */
 799 static inline bool
 800 is_ENOTSUP (int err)
 801 {
 802   return err == EOPNOTSUPP || (ENOTSUP != EOPNOTSUPP && err == ENOTSUP);
 803 }
 804
 805
 806 /* How coreutils quotes filenames, to minimize use of outer quotes,
 807    but also provide better support for copy and paste when used.  */
 808 #include "quotearg.h"
 809
 810 /* Use these to shell quote only when necessary,
 811    when the quoted item is already delimited with colons.  */
 812 #define quotef(arg) \
 813   quotearg_n_style_colon (0, shell_escape_quoting_style, arg)
 814 #define quotef_n(n, arg) \
 815   quotearg_n_style_colon (n, shell_escape_quoting_style, arg)
 816
 817 /* Use these when there are spaces around the file name,
 818    in the error message.  */
 819 #define quoteaf(arg) \
 820   quotearg_style (shell_escape_always_quoting_style, arg)
 821 #define quoteaf_n(n, arg) \
 822   quotearg_n_style (n, shell_escape_always_quoting_style, arg)