src/system.h

   1 /* system-dependent definitions for coreutils
   2    Copyright (C) 1989-2023 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 <stddef.h>
  71 #include <string.h>
  72 #include <errno.h>
  73
  74 /* Some systems don't define this; POSIX mentions it but says it is
  75    obsolete.  gnulib defines it, but only on native Windows systems,
  76    and there only because MSVC 10 does.  */
  77 #ifndef ENODATA
  78 # define ENODATA (-1)
  79 #endif
  80
  81 #include <stdlib.h>
  82 #include "version.h"
  83
  84 /* Exit statuses for programs like 'env' that exec other programs.  */
  85 enum
  86 {
  87   EXIT_TIMEDOUT = 124, /* Time expired before child completed.  */
  88   EXIT_CANCELED = 125, /* Internal error prior to exec attempt.  */
  89   EXIT_CANNOT_INVOKE = 126, /* Program located, but not usable.  */
  90   EXIT_ENOENT = 127 /* Could not find program to exec.  */
  91 };
  92
  93 #include "exitfail.h"
  94
  95 /* Set exit_failure to STATUS if that's not the default already.  */
  96 static inline void
  97 initialize_exit_failure (int status)
  98 {
  99   if (status != EXIT_FAILURE)
 100     exit_failure = status;
 101 }
 102
 103 #include <fcntl.h>
 104 #ifdef O_PATH
 105 enum { O_PATHSEARCH = O_PATH };
 106 #else
 107 enum { O_PATHSEARCH = O_SEARCH };
 108 #endif
 109
 110 #include <dirent.h>
 111 #ifndef _D_EXACT_NAMLEN
 112 # define _D_EXACT_NAMLEN(dp) strlen ((dp)->d_name)
 113 #endif
 114
 115 enum
 116 {
 117   NOT_AN_INODE_NUMBER = 0
 118 };
 119
 120 #ifdef D_INO_IN_DIRENT
 121 # define D_INO(dp) (dp)->d_ino
 122 #else
 123 /* Some systems don't have inodes, so fake them to avoid lots of ifdefs.  */
 124 # define D_INO(dp) NOT_AN_INODE_NUMBER
 125 #endif
 126
 127 /* include here for SIZE_MAX.  */
 128 #include <inttypes.h>
 129
 130 /* Redirection and wildcarding when done by the utility itself.
 131    Generally a noop, but used in particular for OS/2.  */
 132 #ifndef initialize_main
 133 # ifndef __OS2__
 134 #  define initialize_main(ac, av)
 135 # else
 136 #  define initialize_main(ac, av) \
 137      do { _wildcard (ac, av); _response (ac, av); } while (0)
 138 # endif
 139 #endif
 140
 141 #include "stat-macros.h"
 142
 143 #include "timespec.h"
 144
 145 #include <ctype.h>
 146
 147 /* ISDIGIT differs from isdigit, as follows:
 148    - Its arg may be any int or unsigned int; it need not be an unsigned char
 149      or EOF.
 150    - It's typically faster.
 151    POSIX says that only '0' through '9' are digits.  Prefer ISDIGIT to
 152    isdigit unless it's important to use the locale's definition
 153    of 'digit' even when the host does not conform to POSIX.  */
 154 #define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9)
 155
 156 /* Convert a possibly-signed character to an unsigned character.  This is
 157    a bit safer than casting to unsigned char, since it catches some type
 158    errors that the cast doesn't.  */
 159 static inline unsigned char to_uchar (char ch) { return ch; }
 160
 161 /* '\n' is considered a field separator with  --zero-terminated.  */
 162 static inline bool
 163 field_sep (unsigned char ch)
 164 {
 165   return isblank (ch) || ch == '\n';
 166 }
 167
 168 #include <locale.h>
 169
 170 /* Take care of NLS matters.  */
 171
 172 #include "gettext.h"
 173 #if ! ENABLE_NLS
 174 # undef textdomain
 175 # define textdomain(Domainname) /* empty */
 176 # undef bindtextdomain
 177 # define bindtextdomain(Domainname, Dirname) /* empty */
 178 #endif
 179
 180 #define _(msgid) gettext (msgid)
 181 #define N_(msgid) msgid
 182
 183 /* Return a value that pluralizes the same way that N does, in all
 184    languages we know of.  */
 185 static inline unsigned long int
 186 select_plural (uintmax_t n)
 187 {
 188   /* Reduce by a power of ten, but keep it away from zero.  The
 189      gettext manual says 1000000 should be safe.  */
 190   enum { PLURAL_REDUCER = 1000000 };
 191   return (n <= ULONG_MAX ? n : n % PLURAL_REDUCER + PLURAL_REDUCER);
 192 }
 193
 194 #define STREQ(a, b) (strcmp (a, b) == 0)
 195 #define STREQ_LEN(a, b, n) (strncmp (a, b, n) == 0) /* n==-1 means unbounded */
 196 #define STRPREFIX(a, b) (strncmp (a, b, strlen (b)) == 0)
 197
 198 /* Just like strncmp, but the second argument must be a literal string
 199    and you don't specify the length;  that comes from the literal.  */
 200 #define STRNCMP_LIT(s, lit) strncmp (s, "" lit "", sizeof (lit) - 1)
 201
 202 #if !HAVE_DECL_GETLOGIN
 203 char *getlogin (void);
 204 #endif
 205
 206 #if !HAVE_DECL_TTYNAME
 207 char *ttyname (int);
 208 #endif
 209
 210 #if !HAVE_DECL_GETEUID
 211 uid_t geteuid (void);
 212 #endif
 213
 214 #if !HAVE_DECL_GETPWUID
 215 struct passwd *getpwuid (uid_t);
 216 #endif
 217
 218 #if !HAVE_DECL_GETGRGID
 219 struct group *getgrgid (gid_t);
 220 #endif
 221
 222 /* Interix has replacements for getgr{gid,nam,ent}, that don't
 223    query the domain controller for group members when not required.
 224    This speeds up the calls tremendously (<1 ms vs. >3 s). */
 225 /* To protect any system that could provide _nomembers functions
 226    other than interix, check for HAVE_SETGROUPS, as interix is
 227    one of the very few (the only?) platform that lacks it */
 228 #if ! HAVE_SETGROUPS
 229 # if HAVE_GETGRGID_NOMEMBERS
 230 #  define getgrgid(gid) getgrgid_nomembers(gid)
 231 # endif
 232 # if HAVE_GETGRNAM_NOMEMBERS
 233 #  define getgrnam(nam) getgrnam_nomembers(nam)
 234 # endif
 235 # if HAVE_GETGRENT_NOMEMBERS
 236 #  define getgrent() getgrent_nomembers()
 237 # endif
 238 #endif
 239
 240 #if !HAVE_DECL_GETUID
 241 uid_t getuid (void);
 242 #endif
 243
 244 #include "idx.h"
 245 #include "xalloc.h"
 246 #include "verify.h"
 247
 248 /* This is simply a shorthand for the common case in which
 249    the third argument to x2nrealloc would be 'sizeof *(P)'.
 250    Ensure that sizeof *(P) is *not* 1.  In that case, it'd be
 251    better to use X2REALLOC, although not strictly necessary.  */
 252 #define X2NREALLOC(P, PN) verify_expr (sizeof *(P) != 1, \
 253                                        x2nrealloc (P, PN, sizeof *(P)))
 254
 255 /* Using x2realloc (when appropriate) usually makes your code more
 256    readable than using x2nrealloc, but it also makes it so your
 257    code will malfunction if sizeof *(P) ever becomes 2 or greater.
 258    So use this macro instead of using x2realloc directly.  */
 259 #define X2REALLOC(P, PN) verify_expr (sizeof *(P) == 1, \
 260                                       x2realloc (P, PN))
 261
 262 #include "unlocked-io.h"
 263 #include "same-inode.h"
 264
 265 #include "dirname.h"
 266 #include "openat.h"
 267
 268 static inline bool
 269 dot_or_dotdot (char const *file_name)
 270 {
 271   if (file_name[0] == '.')
 272     {
 273       char sep = file_name[(file_name[1] == '.') + 1];
 274       return (! sep || ISSLASH (sep));
 275     }
 276   else
 277     return false;
 278 }
 279
 280 /* A wrapper for readdir so that callers don't see entries for '.' or '..'.  */
 281 static inline struct dirent const *
 282 readdir_ignoring_dot_and_dotdot (DIR *dirp)
 283 {
 284   while (true)
 285     {
 286       struct dirent const *dp = readdir (dirp);
 287       if (dp == nullptr || ! dot_or_dotdot (dp->d_name))
 288         return dp;
 289     }
 290 }
 291
 292 /* Return -1 if DIR is an empty directory,
 293    0 if DIR is a nonempty directory,
 294    and a positive error number if there was trouble determining
 295    whether DIR is an empty or nonempty directory.  */
 296 enum {
 297     DS_UNKNOWN = -2,
 298     DS_EMPTY = -1,
 299     DS_NONEMPTY = 0,
 300 };
 301 static inline int
 302 directory_status (int fd_cwd, char const *dir)
 303 {
 304   DIR *dirp;
 305   bool no_direntries;
 306   int saved_errno;
 307   int fd = openat (fd_cwd, dir,
 308                    (O_RDONLY | O_DIRECTORY
 309                     | O_NOCTTY | O_NOFOLLOW | O_NONBLOCK));
 310
 311   if (fd < 0)
 312     return errno;
 313
 314   dirp = fdopendir (fd);
 315   if (dirp == nullptr)
 316     {
 317       saved_errno = errno;
 318       close (fd);
 319       return saved_errno;
 320     }
 321
 322   errno = 0;
 323   no_direntries = !readdir_ignoring_dot_and_dotdot (dirp);
 324   saved_errno = errno;
 325   closedir (dirp);
 326   return no_direntries && saved_errno == 0 ? DS_EMPTY : saved_errno;
 327 }
 328
 329 /* Factor out some of the common --help and --version processing code.  */
 330
 331 /* These enum values cannot possibly conflict with the option values
 332    ordinarily used by commands, including CHAR_MAX + 1, etc.  Avoid
 333    CHAR_MIN - 1, as it may equal -1, the getopt end-of-options value.  */
 334 enum
 335 {
 336   GETOPT_HELP_CHAR = (CHAR_MIN - 2),
 337   GETOPT_VERSION_CHAR = (CHAR_MIN - 3)
 338 };
 339
 340 #define GETOPT_HELP_OPTION_DECL \
 341   "help", no_argument, nullptr, GETOPT_HELP_CHAR
 342 #define GETOPT_VERSION_OPTION_DECL \
 343   "version", no_argument, nullptr, GETOPT_VERSION_CHAR
 344 #define GETOPT_SELINUX_CONTEXT_OPTION_DECL \
 345   "context", optional_argument, nullptr, 'Z'
 346
 347 #define case_GETOPT_HELP_CHAR                   \
 348   case GETOPT_HELP_CHAR:                        \
 349     usage (EXIT_SUCCESS);                       \
 350     break;
 351
 352 /* Program_name must be a literal string.
 353    Usually it is just PROGRAM_NAME.  */
 354 #define USAGE_BUILTIN_WARNING \
 355   _("\n" \
 356 "NOTE: your shell may have its own version of %s, which usually supersedes\n" \
 357 "the version described here.  Please refer to your shell's documentation\n" \
 358 "for details about the options it supports.\n")
 359
 360 #define HELP_OPTION_DESCRIPTION \
 361   _("      --help        display this help and exit\n")
 362 #define VERSION_OPTION_DESCRIPTION \
 363   _("      --version     output version information and exit\n")
 364
 365 #include "closein.h"
 366 #include "closeout.h"
 367
 368 #define emit_bug_reporting_address unused__emit_bug_reporting_address
 369 #include "version-etc.h"
 370 #undef emit_bug_reporting_address
 371
 372 #include "propername.h"
 373 /* Define away proper_name (leaving proper_name_utf8, which affects far
 374    fewer programs), since it's not worth the cost of adding ~17KB to
 375    the x86_64 text size of every single program.  This avoids a 40%
 376    (almost ~2MB) increase in the file system space utilization for the set
 377    of the 100 binaries. */
 378 #define proper_name(x) (x)
 379
 380 #include "progname.h"
 381
 382 #define case_GETOPT_VERSION_CHAR(Program_name, Authors)                 \
 383   case GETOPT_VERSION_CHAR:                                             \
 384     version_etc (stdout, Program_name, PACKAGE_NAME, Version, Authors,  \
 385                  (char *) nullptr);                                     \
 386     exit (EXIT_SUCCESS);                                                \
 387     break;
 388
 389 #include "minmax.h"
 390 #include "intprops.h"
 391
 392 #ifndef SSIZE_MAX
 393 # define SSIZE_MAX TYPE_MAXIMUM (ssize_t)
 394 #endif
 395
 396 #ifndef OFF_T_MIN
 397 # define OFF_T_MIN TYPE_MINIMUM (off_t)
 398 #endif
 399
 400 #ifndef OFF_T_MAX
 401 # define OFF_T_MAX TYPE_MAXIMUM (off_t)
 402 #endif
 403
 404 #ifndef UID_T_MAX
 405 # define UID_T_MAX TYPE_MAXIMUM (uid_t)
 406 #endif
 407
 408 #ifndef GID_T_MAX
 409 # define GID_T_MAX TYPE_MAXIMUM (gid_t)
 410 #endif
 411
 412 #ifndef PID_T_MAX
 413 # define PID_T_MAX TYPE_MAXIMUM (pid_t)
 414 #endif
 415
 416 /* Use this to suppress gcc warnings.  */
 417 #ifdef lint
 418 # define IF_LINT(Code) Code
 419 #else
 420 # define IF_LINT(Code) /* empty */
 421 #endif
 422
 423 /* main_exit should be called only from the main function.  It is
 424    equivalent to 'exit'.  When checking for lint it calls 'exit', to
 425    pacify gcc -fsanitize=lint which would otherwise have false alarms
 426    for pointers in the main function's activation record.  Otherwise
 427    it simply returns from 'main'; this used to be what gcc's static
 428    checking preferred and may yet be again.  */
 429 #ifdef lint
 430 # define main_exit(status) exit (status)
 431 #else
 432 # define main_exit(status) return status
 433 #endif
 434
 435 #ifdef __GNUC__
 436 # define LIKELY(cond)    __builtin_expect ((cond), 1)
 437 # define UNLIKELY(cond)  __builtin_expect ((cond), 0)
 438 #else
 439 # define LIKELY(cond)    (cond)
 440 # define UNLIKELY(cond)  (cond)
 441 #endif
 442
 443
 444 #if defined strdupa
 445 # define ASSIGN_STRDUPA(DEST, S)                \
 446   do { DEST = strdupa (S); } while (0)
 447 #else
 448 # define ASSIGN_STRDUPA(DEST, S)                \
 449   do                                            \
 450     {                                           \
 451       char const *s_ = (S);                     \
 452       size_t len_ = strlen (s_) + 1;            \
 453       char *tmp_dest_ = alloca (len_);          \
 454       DEST = memcpy (tmp_dest_, s_, len_);      \
 455     }                                           \
 456   while (0)
 457 #endif
 458
 459 #if ! HAVE_SYNC
 460 # define sync() /* empty */
 461 #endif
 462
 463 /* Compute the greatest common divisor of U and V using Euclid's
 464    algorithm.  U and V must be nonzero.  */
 465
 466 ATTRIBUTE_CONST
 467 static inline size_t
 468 gcd (size_t u, size_t v)
 469 {
 470   do
 471     {
 472       size_t t = u % v;
 473       u = v;
 474       v = t;
 475     }
 476   while (v);
 477
 478   return u;
 479 }
 480
 481 /* Compute the least common multiple of U and V.  U and V must be
 482    nonzero.  There is no overflow checking, so callers should not
 483    specify outlandish sizes.  */
 484
 485 ATTRIBUTE_CONST
 486 static inline size_t
 487 lcm (size_t u, size_t v)
 488 {
 489   return u * (v / gcd (u, v));
 490 }
 491
 492 /* Return PTR, aligned upward to the next multiple of ALIGNMENT.
 493    ALIGNMENT must be nonzero.  The caller must arrange for ((char *)
 494    PTR) through ((char *) PTR + ALIGNMENT - 1) to be addressable
 495    locations.  */
 496
 497 static inline void *
 498 ptr_align (void const *ptr, size_t alignment)
 499 {
 500   char const *p0 = ptr;
 501   char const *p1 = p0 + alignment - 1;
 502   return (void *) (p1 - (size_t) p1 % alignment);
 503 }
 504
 505 /* Return whether the buffer consists entirely of NULs.
 506    Based on memeqzero in CCAN by Rusty Russell under CC0 (Public domain).  */
 507
 508 ATTRIBUTE_PURE
 509 static inline bool
 510 is_nul (void const *buf, size_t length)
 511 {
 512   const unsigned char *p = buf;
 513 /* Using possibly unaligned access for the first 16 bytes
 514    saves about 30-40 cycles, though it is strictly undefined behavior
 515    and so would need __attribute__ ((__no_sanitize_undefined__))
 516    to avoid -fsanitize=undefined warnings.
 517    Considering coreutils is mainly concerned with relatively
 518    large buffers, we'll just use the defined behavior.  */
 519 #if 0 && (_STRING_ARCH_unaligned || _STRING_INLINE_unaligned)
 520   unsigned long word;
 521 #else
 522   unsigned char word;
 523 #endif
 524
 525   if (! length)
 526       return true;
 527
 528   /* Check len bytes not aligned on a word.  */
 529   while (UNLIKELY (length & (sizeof word - 1)))
 530     {
 531       if (*p)
 532         return false;
 533       p++;
 534       length--;
 535       if (! length)
 536         return true;
 537    }
 538
 539   /* Check up to 16 bytes a word at a time.  */
 540   for (;;)
 541     {
 542       memcpy (&word, p, sizeof word);
 543       if (word)
 544         return false;
 545       p += sizeof word;
 546       length -= sizeof word;
 547       if (! length)
 548         return true;
 549       if (UNLIKELY (length & 15) == 0)
 550         break;
 551    }
 552
 553    /* Now we know first 16 bytes are NUL, memcmp with self.  */
 554    return memcmp (buf, p, length) == 0;
 555 }
 556
 557 /* If 10*Accum + Digit_val is larger than the maximum value for Type,
 558    then don't update Accum and return false to indicate it would
 559    overflow.  Otherwise, set Accum to that new value and return true.
 560    Verify at compile-time that Type is Accum's type, and that Type is
 561    unsigned.  Accum must be an object, so that we can take its
 562    address.  Accum and Digit_val may be evaluated multiple times.
 563
 564    The "Added check" below is not strictly required, but it causes GCC
 565    to return a nonzero exit status instead of merely a warning
 566    diagnostic, and that is more useful.  */
 567
 568 #define DECIMAL_DIGIT_ACCUMULATE(Accum, Digit_val, Type)                \
 569   (                                                                     \
 570    (void) (&(Accum) == (Type *) nullptr),  /* The type matches.  */     \
 571    verify_expr (! TYPE_SIGNED (Type), /* The type is unsigned.  */      \
 572                 (((Type) -1 / 10 < (Accum)                              \
 573                   || (Type) ((Accum) * 10 + (Digit_val)) < (Accum))     \
 574                  ? false                                                \
 575                  : (((Accum) = (Accum) * 10 + (Digit_val)), true)))     \
 576   )
 577
 578 static inline void
 579 emit_stdin_note (void)
 580 {
 581   fputs (_("\n\
 582 With no FILE, or when FILE is -, read standard input.\n\
 583 "), stdout);
 584 }
 585 static inline void
 586 emit_mandatory_arg_note (void)
 587 {
 588   fputs (_("\n\
 589 Mandatory arguments to long options are mandatory for short options too.\n\
 590 "), stdout);
 591 }
 592
 593 static inline void
 594 emit_size_note (void)
 595 {
 596   fputs (_("\n\
 597 The SIZE argument is an integer and optional unit (example: 10K is 10*1024).\n\
 598 Units are K,M,G,T,P,E,Z,Y,R,Q (powers of 1024) or KB,MB,... (powers of 1000).\n\
 599 Binary prefixes can be used, too: KiB=K, MiB=M, and so on.\n\
 600 "), stdout);
 601 }
 602
 603 static inline void
 604 emit_blocksize_note (char const *program)
 605 {
 606   printf (_("\n\
 607 Display values are in units of the first available SIZE from --block-size,\n\
 608 and the %s_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables.\n\
 609 Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set).\n\
 610 "), program);
 611 }
 612
 613 static inline void
 614 emit_update_parameters_note (void)
 615 {
 616   fputs (_("\
 617 \n\
 618 UPDATE controls which existing files in the destination are replaced.\n\
 619 'all' is the default operation when an --update option is not specified,\n\
 620 and results in all existing files in the destination being replaced.\n\
 621 'none' is similar to the --no-clobber option, in that no files in the\n\
 622 destination are replaced, but also skipped files do not induce a failure.\n\
 623 'older' is the default operation when --update is specified, and results\n\
 624 in files being replaced if they're older than the corresponding source file.\n\
 625 "), stdout);
 626 }
 627
 628 static inline void
 629 emit_backup_suffix_note (void)
 630 {
 631   fputs (_("\
 632 \n\
 633 The backup suffix is '~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX.\n\
 634 The version control method may be selected via the --backup option or through\n\
 635 the VERSION_CONTROL environment variable.  Here are the values:\n\
 636 \n\
 637 "), stdout);
 638   fputs (_("\
 639   none, off       never make backups (even if --backup is given)\n\
 640   numbered, t     make numbered backups\n\
 641   existing, nil   numbered if numbered backups exist, simple otherwise\n\
 642   simple, never   always make simple backups\n\
 643 "), stdout);
 644 }
 645
 646 static inline void
 647 emit_exec_status (char const *program)
 648 {
 649       printf (_("\n\
 650 Exit status:\n\
 651   125  if the %s command itself fails\n\
 652   126  if COMMAND is found but cannot be invoked\n\
 653   127  if COMMAND cannot be found\n\
 654   -    the exit status of COMMAND otherwise\n\
 655 "), program);
 656 }
 657
 658 static inline void
 659 emit_ancillary_info (char const *program)
 660 {
 661   struct infomap { char const *program; char const *node; } const infomap[] = {
 662     { "[", "test invocation" },
 663     { "coreutils", "Multi-call invocation" },
 664     { "sha224sum", "sha2 utilities" },
 665     { "sha256sum", "sha2 utilities" },
 666     { "sha384sum", "sha2 utilities" },
 667     { "sha512sum", "sha2 utilities" },
 668     { nullptr, nullptr }
 669   };
 670
 671   char const *node = program;
 672   struct infomap const *map_prog = infomap;
 673
 674   while (map_prog->program && ! STREQ (program, map_prog->program))
 675     map_prog++;
 676
 677   if (map_prog->node)
 678     node = map_prog->node;
 679
 680   printf (_("\n%s online help: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
 681
 682   /* Don't output this redundant message for English locales.
 683      Note we still output for 'C' so that it gets included in the man page.  */
 684   char const *lc_messages = setlocale (LC_MESSAGES, nullptr);
 685   if (lc_messages && STRNCMP_LIT (lc_messages, "en_"))
 686     {
 687       /* TRANSLATORS: Replace LANG_CODE in this URL with your language code
 688          <https://translationproject.org/team/LANG_CODE.html> to form one of
 689          the URLs at https://translationproject.org/team/.  Otherwise, replace
 690          the entire URL with your translation team's email address.  */
 691       fputs (_("Report any translation bugs to "
 692                "<https://translationproject.org/team/>\n"), stdout);
 693     }
 694   /* .htaccess on the coreutils web site maps programs to the appropriate page,
 695      however we explicitly handle "[" -> "test" here as the "[" is not
 696      recognized as part of a URL by default in terminals.  */
 697   char const *url_program = STREQ (program, "[") ? "test" : program;
 698   printf (_("Full documentation <%s%s>\n"),
 699           PACKAGE_URL, url_program);
 700   printf (_("or available locally via: info '(coreutils) %s%s'\n"),
 701           node, node == program ? " invocation" : "");
 702 }
 703
 704 /* Use a macro rather than an inline function, as this references
 705    the global program_name, which causes dynamic linking issues
 706    in libstdbuf.so on some systems where unused functions
 707    are not removed by the linker.  */
 708 #define emit_try_help() \
 709   do \
 710     { \
 711       fprintf (stderr, _("Try '%s --help' for more information.\n"), \
 712                program_name); \
 713     } \
 714   while (0)
 715
 716 #include "inttostr.h"
 717
 718 static inline char *
 719 timetostr (time_t t, char *buf)
 720 {
 721   return (TYPE_SIGNED (time_t)
 722           ? imaxtostr (t, buf)
 723           : umaxtostr (t, buf));
 724 }
 725
 726 static inline char *
 727 bad_cast (char const *s)
 728 {
 729   return (char *) s;
 730 }
 731
 732 /* Return a boolean indicating whether SB->st_size is defined.  */
 733 static inline bool
 734 usable_st_size (struct stat const *sb)
 735 {
 736   return (S_ISREG (sb->st_mode) || S_ISLNK (sb->st_mode)
 737           || S_TYPEISSHM (sb) || S_TYPEISTMO (sb));
 738 }
 739
 740 _Noreturn void usage (int status);
 741
 742 #include "error.h"
 743
 744 /* Like error(0, 0, ...), but without an implicit newline.
 745    Also a noop unless the global DEV_DEBUG is set.  */
 746 #define devmsg(...)                     \
 747   do                                    \
 748     {                                   \
 749       if (dev_debug)                    \
 750         fprintf (stderr, __VA_ARGS__);  \
 751     }                                   \
 752   while (0)
 753
 754 #define emit_cycle_warning(file_name)   \
 755   do                                    \
 756     {                                   \
 757       error (0, 0, _("\
 758 WARNING: Circular directory structure.\n\
 759 This almost certainly means that you have a corrupted file system.\n\
 760 NOTIFY YOUR SYSTEM MANAGER.\n\
 761 The following directory is part of the cycle:\n  %s\n"), \
 762              quotef (file_name));       \
 763     }                                   \
 764   while (0)
 765
 766 /* exit with a _single_ "write error" diagnostic.  */
 767
 768 static inline void
 769 write_error (void)
 770 {
 771   int saved_errno = errno;
 772   fflush (stdout);    /* Ensure nothing buffered that might induce an error. */
 773   clearerr (stdout);  /* To avoid extraneous diagnostic from close_stdout.  */
 774   error (EXIT_FAILURE, saved_errno, _("write error"));
 775 }
 776
 777 /* Like stpncpy, but do ensure that the result is NUL-terminated,
 778    and do not NUL-pad out to LEN.  I.e., when strnlen (src, len) == len,
 779    this function writes a NUL byte into dest[len].  Thus, the length
 780    of the destination buffer must be at least LEN + 1.
 781    The DEST and SRC buffers must not overlap.  */
 782 static inline char *
 783 stzncpy (char *restrict dest, char const *restrict src, size_t len)
 784 {
 785   size_t i;
 786   for (i = 0; i < len && *src; i++)
 787     *dest++ = *src++;
 788   *dest = 0;
 789   return dest;
 790 }
 791
 792 #ifndef ARRAY_CARDINALITY
 793 # define ARRAY_CARDINALITY(Array) (sizeof (Array) / sizeof *(Array))
 794 #endif
 795
 796 /* Return true if ERR is ENOTSUP or EOPNOTSUPP, otherwise false.
 797    This wrapper function avoids the redundant 'or'd comparison on
 798    systems like Linux for which they have the same value.  It also
 799    avoids the gcc warning to that effect.  */
 800 static inline bool
 801 is_ENOTSUP (int err)
 802 {
 803   return err == EOPNOTSUPP || (ENOTSUP != EOPNOTSUPP && err == ENOTSUP);
 804 }
 805
 806
 807 /* How coreutils quotes filenames, to minimize use of outer quotes,
 808    but also provide better support for copy and paste when used.  */
 809 #include "quotearg.h"
 810
 811 /* Use these to shell quote only when necessary,
 812    when the quoted item is already delimited with colons.  */
 813 #define quotef(arg) \
 814   quotearg_n_style_colon (0, shell_escape_quoting_style, arg)
 815 #define quotef_n(n, arg) \
 816   quotearg_n_style_colon (n, shell_escape_quoting_style, arg)
 817
 818 /* Use these when there are spaces around the file name,
 819    in the error message.  */
 820 #define quoteaf(arg) \
 821   quotearg_style (shell_escape_always_quoting_style, arg)
 822 #define quoteaf_n(n, arg) \
 823   quotearg_n_style (n, shell_escape_always_quoting_style, arg)