libiberty/strerror.c

   1 /* Extended support for using errno values.
   2    Written by Fred Fish.  fnf@cygnus.com
   3    This file is in the public domain.  --Per Bothner.  */
   4
   5 #include "ansidecl.h"
   6 #include "libiberty.h"
   7
   8 #include "config.h"
   9
  10 #ifdef HAVE_SYS_ERRLIST
  11 /* Note that errno.h (not sure what OS) or stdio.h (BSD 4.4, at least)
  12    might declare sys_errlist in a way that the compiler might consider
  13    incompatible with our later declaration, perhaps by using const
  14    attributes.  So we hide the declaration in errno.h (if any) using a
  15    macro. */
  16 #define sys_nerr sys_nerr__
  17 #define sys_errlist sys_errlist__
  18 #endif
  19
  20 #include <stdio.h>
  21 #include <errno.h>
  22
  23 #ifdef HAVE_SYS_ERRLIST
  24 #undef sys_nerr
  25 #undef sys_errlist
  26 #endif
  27
  28 /*  Routines imported from standard C runtime libraries. */
  29
  30 #ifdef HAVE_STDLIB_H
  31 #include <stdlib.h>
  32 #else
  33 extern PTR malloc ();
  34 #endif
  35
  36 #ifdef HAVE_STRING_H
  37 #include <string.h>
  38 #else
  39 extern PTR memset ();
  40 #endif
  41
  42 #ifndef MAX
  43 #  define MAX(a,b) ((a) > (b) ? (a) : (b))
  44 #endif
  45
  46 static void init_error_tables PARAMS ((void));
  47
  48 /* Translation table for errno values.  See intro(2) in most UNIX systems
  49    Programmers Reference Manuals.
  50
  51    Note that this table is generally only accessed when it is used at runtime
  52    to initialize errno name and message tables that are indexed by errno
  53    value.
  54
  55    Not all of these errnos will exist on all systems.  This table is the only
  56    thing that should have to be updated as new error numbers are introduced.
  57    It's sort of ugly, but at least its portable. */
  58
  59 struct error_info
  60 {
  61   const int value;              /* The numeric value from <errno.h> */
  62   const char *const name;       /* The equivalent symbolic value */
  63 #ifndef HAVE_SYS_ERRLIST
  64   const char *const msg;        /* Short message about this value */
  65 #endif
  66 };
  67
  68 #ifndef HAVE_SYS_ERRLIST
  69 #   define ENTRY(value, name, msg)      {value, name, msg}
  70 #else
  71 #   define ENTRY(value, name, msg)      {value, name}
  72 #endif
  73
  74 static const struct error_info error_table[] =
  75 {
  76 #if defined (EPERM)
  77   ENTRY(EPERM, "EPERM", "Not owner"),
  78 #endif
  79 #if defined (ENOENT)
  80   ENTRY(ENOENT, "ENOENT", "No such file or directory"),
  81 #endif
  82 #if defined (ESRCH)
  83   ENTRY(ESRCH, "ESRCH", "No such process"),
  84 #endif
  85 #if defined (EINTR)
  86   ENTRY(EINTR, "EINTR", "Interrupted system call"),
  87 #endif
  88 #if defined (EIO)
  89   ENTRY(EIO, "EIO", "I/O error"),
  90 #endif
  91 #if defined (ENXIO)
  92   ENTRY(ENXIO, "ENXIO", "No such device or address"),
  93 #endif
  94 #if defined (E2BIG)
  95   ENTRY(E2BIG, "E2BIG", "Arg list too long"),
  96 #endif
  97 #if defined (ENOEXEC)
  98   ENTRY(ENOEXEC, "ENOEXEC", "Exec format error"),
  99 #endif
 100 #if defined (EBADF)
 101   ENTRY(EBADF, "EBADF", "Bad file number"),
 102 #endif
 103 #if defined (ECHILD)
 104   ENTRY(ECHILD, "ECHILD", "No child processes"),
 105 #endif
 106 #if defined (EWOULDBLOCK)       /* Put before EAGAIN, sometimes aliased */
 107   ENTRY(EWOULDBLOCK, "EWOULDBLOCK", "Operation would block"),
 108 #endif
 109 #if defined (EAGAIN)
 110   ENTRY(EAGAIN, "EAGAIN", "No more processes"),
 111 #endif
 112 #if defined (ENOMEM)
 113   ENTRY(ENOMEM, "ENOMEM", "Not enough space"),
 114 #endif
 115 #if defined (EACCES)
 116   ENTRY(EACCES, "EACCES", "Permission denied"),
 117 #endif
 118 #if defined (EFAULT)
 119   ENTRY(EFAULT, "EFAULT", "Bad address"),
 120 #endif
 121 #if defined (ENOTBLK)
 122   ENTRY(ENOTBLK, "ENOTBLK", "Block device required"),
 123 #endif
 124 #if defined (EBUSY)
 125   ENTRY(EBUSY, "EBUSY", "Device busy"),
 126 #endif
 127 #if defined (EEXIST)
 128   ENTRY(EEXIST, "EEXIST", "File exists"),
 129 #endif
 130 #if defined (EXDEV)
 131   ENTRY(EXDEV, "EXDEV", "Cross-device link"),
 132 #endif
 133 #if defined (ENODEV)
 134   ENTRY(ENODEV, "ENODEV", "No such device"),
 135 #endif
 136 #if defined (ENOTDIR)
 137   ENTRY(ENOTDIR, "ENOTDIR", "Not a directory"),
 138 #endif
 139 #if defined (EISDIR)
 140   ENTRY(EISDIR, "EISDIR", "Is a directory"),
 141 #endif
 142 #if defined (EINVAL)
 143   ENTRY(EINVAL, "EINVAL", "Invalid argument"),
 144 #endif
 145 #if defined (ENFILE)
 146   ENTRY(ENFILE, "ENFILE", "File table overflow"),
 147 #endif
 148 #if defined (EMFILE)
 149   ENTRY(EMFILE, "EMFILE", "Too many open files"),
 150 #endif
 151 #if defined (ENOTTY)
 152   ENTRY(ENOTTY, "ENOTTY", "Not a typewriter"),
 153 #endif
 154 #if defined (ETXTBSY)
 155   ENTRY(ETXTBSY, "ETXTBSY", "Text file busy"),
 156 #endif
 157 #if defined (EFBIG)
 158   ENTRY(EFBIG, "EFBIG", "File too large"),
 159 #endif
 160 #if defined (ENOSPC)
 161   ENTRY(ENOSPC, "ENOSPC", "No space left on device"),
 162 #endif
 163 #if defined (ESPIPE)
 164   ENTRY(ESPIPE, "ESPIPE", "Illegal seek"),
 165 #endif
 166 #if defined (EROFS)
 167   ENTRY(EROFS, "EROFS", "Read-only file system"),
 168 #endif
 169 #if defined (EMLINK)
 170   ENTRY(EMLINK, "EMLINK", "Too many links"),
 171 #endif
 172 #if defined (EPIPE)
 173   ENTRY(EPIPE, "EPIPE", "Broken pipe"),
 174 #endif
 175 #if defined (EDOM)
 176   ENTRY(EDOM, "EDOM", "Math argument out of domain of func"),
 177 #endif
 178 #if defined (ERANGE)
 179   ENTRY(ERANGE, "ERANGE", "Math result not representable"),
 180 #endif
 181 #if defined (ENOMSG)
 182   ENTRY(ENOMSG, "ENOMSG", "No message of desired type"),
 183 #endif
 184 #if defined (EIDRM)
 185   ENTRY(EIDRM, "EIDRM", "Identifier removed"),
 186 #endif
 187 #if defined (ECHRNG)
 188   ENTRY(ECHRNG, "ECHRNG", "Channel number out of range"),
 189 #endif
 190 #if defined (EL2NSYNC)
 191   ENTRY(EL2NSYNC, "EL2NSYNC", "Level 2 not synchronized"),
 192 #endif
 193 #if defined (EL3HLT)
 194   ENTRY(EL3HLT, "EL3HLT", "Level 3 halted"),
 195 #endif
 196 #if defined (EL3RST)
 197   ENTRY(EL3RST, "EL3RST", "Level 3 reset"),
 198 #endif
 199 #if defined (ELNRNG)
 200   ENTRY(ELNRNG, "ELNRNG", "Link number out of range"),
 201 #endif
 202 #if defined (EUNATCH)
 203   ENTRY(EUNATCH, "EUNATCH", "Protocol driver not attached"),
 204 #endif
 205 #if defined (ENOCSI)
 206   ENTRY(ENOCSI, "ENOCSI", "No CSI structure available"),
 207 #endif
 208 #if defined (EL2HLT)
 209   ENTRY(EL2HLT, "EL2HLT", "Level 2 halted"),
 210 #endif
 211 #if defined (EDEADLK)
 212   ENTRY(EDEADLK, "EDEADLK", "Deadlock condition"),
 213 #endif
 214 #if defined (ENOLCK)
 215   ENTRY(ENOLCK, "ENOLCK", "No record locks available"),
 216 #endif
 217 #if defined (EBADE)
 218   ENTRY(EBADE, "EBADE", "Invalid exchange"),
 219 #endif
 220 #if defined (EBADR)
 221   ENTRY(EBADR, "EBADR", "Invalid request descriptor"),
 222 #endif
 223 #if defined (EXFULL)
 224   ENTRY(EXFULL, "EXFULL", "Exchange full"),
 225 #endif
 226 #if defined (ENOANO)
 227   ENTRY(ENOANO, "ENOANO", "No anode"),
 228 #endif
 229 #if defined (EBADRQC)
 230   ENTRY(EBADRQC, "EBADRQC", "Invalid request code"),
 231 #endif
 232 #if defined (EBADSLT)
 233   ENTRY(EBADSLT, "EBADSLT", "Invalid slot"),
 234 #endif
 235 #if defined (EDEADLOCK)
 236   ENTRY(EDEADLOCK, "EDEADLOCK", "File locking deadlock error"),
 237 #endif
 238 #if defined (EBFONT)
 239   ENTRY(EBFONT, "EBFONT", "Bad font file format"),
 240 #endif
 241 #if defined (ENOSTR)
 242   ENTRY(ENOSTR, "ENOSTR", "Device not a stream"),
 243 #endif
 244 #if defined (ENODATA)
 245   ENTRY(ENODATA, "ENODATA", "No data available"),
 246 #endif
 247 #if defined (ETIME)
 248   ENTRY(ETIME, "ETIME", "Timer expired"),
 249 #endif
 250 #if defined (ENOSR)
 251   ENTRY(ENOSR, "ENOSR", "Out of streams resources"),
 252 #endif
 253 #if defined (ENONET)
 254   ENTRY(ENONET, "ENONET", "Machine is not on the network"),
 255 #endif
 256 #if defined (ENOPKG)
 257   ENTRY(ENOPKG, "ENOPKG", "Package not installed"),
 258 #endif
 259 #if defined (EREMOTE)
 260   ENTRY(EREMOTE, "EREMOTE", "Object is remote"),
 261 #endif
 262 #if defined (ENOLINK)
 263   ENTRY(ENOLINK, "ENOLINK", "Link has been severed"),
 264 #endif
 265 #if defined (EADV)
 266   ENTRY(EADV, "EADV", "Advertise error"),
 267 #endif
 268 #if defined (ESRMNT)
 269   ENTRY(ESRMNT, "ESRMNT", "Srmount error"),
 270 #endif
 271 #if defined (ECOMM)
 272   ENTRY(ECOMM, "ECOMM", "Communication error on send"),
 273 #endif
 274 #if defined (EPROTO)
 275   ENTRY(EPROTO, "EPROTO", "Protocol error"),
 276 #endif
 277 #if defined (EMULTIHOP)
 278   ENTRY(EMULTIHOP, "EMULTIHOP", "Multihop attempted"),
 279 #endif
 280 #if defined (EDOTDOT)
 281   ENTRY(EDOTDOT, "EDOTDOT", "RFS specific error"),
 282 #endif
 283 #if defined (EBADMSG)
 284   ENTRY(EBADMSG, "EBADMSG", "Not a data message"),
 285 #endif
 286 #if defined (ENAMETOOLONG)
 287   ENTRY(ENAMETOOLONG, "ENAMETOOLONG", "File name too long"),
 288 #endif
 289 #if defined (EOVERFLOW)
 290   ENTRY(EOVERFLOW, "EOVERFLOW", "Value too large for defined data type"),
 291 #endif
 292 #if defined (ENOTUNIQ)
 293   ENTRY(ENOTUNIQ, "ENOTUNIQ", "Name not unique on network"),
 294 #endif
 295 #if defined (EBADFD)
 296   ENTRY(EBADFD, "EBADFD", "File descriptor in bad state"),
 297 #endif
 298 #if defined (EREMCHG)
 299   ENTRY(EREMCHG, "EREMCHG", "Remote address changed"),
 300 #endif
 301 #if defined (ELIBACC)
 302   ENTRY(ELIBACC, "ELIBACC", "Can not access a needed shared library"),
 303 #endif
 304 #if defined (ELIBBAD)
 305   ENTRY(ELIBBAD, "ELIBBAD", "Accessing a corrupted shared library"),
 306 #endif
 307 #if defined (ELIBSCN)
 308   ENTRY(ELIBSCN, "ELIBSCN", ".lib section in a.out corrupted"),
 309 #endif
 310 #if defined (ELIBMAX)
 311   ENTRY(ELIBMAX, "ELIBMAX", "Attempting to link in too many shared libraries"),
 312 #endif
 313 #if defined (ELIBEXEC)
 314   ENTRY(ELIBEXEC, "ELIBEXEC", "Cannot exec a shared library directly"),
 315 #endif
 316 #if defined (EILSEQ)
 317   ENTRY(EILSEQ, "EILSEQ", "Illegal byte sequence"),
 318 #endif
 319 #if defined (ENOSYS)
 320   ENTRY(ENOSYS, "ENOSYS", "Operation not applicable"),
 321 #endif
 322 #if defined (ELOOP)
 323   ENTRY(ELOOP, "ELOOP", "Too many symbolic links encountered"),
 324 #endif
 325 #if defined (ERESTART)
 326   ENTRY(ERESTART, "ERESTART", "Interrupted system call should be restarted"),
 327 #endif
 328 #if defined (ESTRPIPE)
 329   ENTRY(ESTRPIPE, "ESTRPIPE", "Streams pipe error"),
 330 #endif
 331 #if defined (ENOTEMPTY)
 332   ENTRY(ENOTEMPTY, "ENOTEMPTY", "Directory not empty"),
 333 #endif
 334 #if defined (EUSERS)
 335   ENTRY(EUSERS, "EUSERS", "Too many users"),
 336 #endif
 337 #if defined (ENOTSOCK)
 338   ENTRY(ENOTSOCK, "ENOTSOCK", "Socket operation on non-socket"),
 339 #endif
 340 #if defined (EDESTADDRREQ)
 341   ENTRY(EDESTADDRREQ, "EDESTADDRREQ", "Destination address required"),
 342 #endif
 343 #if defined (EMSGSIZE)
 344   ENTRY(EMSGSIZE, "EMSGSIZE", "Message too long"),
 345 #endif
 346 #if defined (EPROTOTYPE)
 347   ENTRY(EPROTOTYPE, "EPROTOTYPE", "Protocol wrong type for socket"),
 348 #endif
 349 #if defined (ENOPROTOOPT)
 350   ENTRY(ENOPROTOOPT, "ENOPROTOOPT", "Protocol not available"),
 351 #endif
 352 #if defined (EPROTONOSUPPORT)
 353   ENTRY(EPROTONOSUPPORT, "EPROTONOSUPPORT", "Protocol not supported"),
 354 #endif
 355 #if defined (ESOCKTNOSUPPORT)
 356   ENTRY(ESOCKTNOSUPPORT, "ESOCKTNOSUPPORT", "Socket type not supported"),
 357 #endif
 358 #if defined (EOPNOTSUPP)
 359   ENTRY(EOPNOTSUPP, "EOPNOTSUPP", "Operation not supported on transport endpoint"),
 360 #endif
 361 #if defined (EPFNOSUPPORT)
 362   ENTRY(EPFNOSUPPORT, "EPFNOSUPPORT", "Protocol family not supported"),
 363 #endif
 364 #if defined (EAFNOSUPPORT)
 365   ENTRY(EAFNOSUPPORT, "EAFNOSUPPORT", "Address family not supported by protocol"),
 366 #endif
 367 #if defined (EADDRINUSE)
 368   ENTRY(EADDRINUSE, "EADDRINUSE", "Address already in use"),
 369 #endif
 370 #if defined (EADDRNOTAVAIL)
 371   ENTRY(EADDRNOTAVAIL, "EADDRNOTAVAIL","Cannot assign requested address"),
 372 #endif
 373 #if defined (ENETDOWN)
 374   ENTRY(ENETDOWN, "ENETDOWN", "Network is down"),
 375 #endif
 376 #if defined (ENETUNREACH)
 377   ENTRY(ENETUNREACH, "ENETUNREACH", "Network is unreachable"),
 378 #endif
 379 #if defined (ENETRESET)
 380   ENTRY(ENETRESET, "ENETRESET", "Network dropped connection because of reset"),
 381 #endif
 382 #if defined (ECONNABORTED)
 383   ENTRY(ECONNABORTED, "ECONNABORTED", "Software caused connection abort"),
 384 #endif
 385 #if defined (ECONNRESET)
 386   ENTRY(ECONNRESET, "ECONNRESET", "Connection reset by peer"),
 387 #endif
 388 #if defined (ENOBUFS)
 389   ENTRY(ENOBUFS, "ENOBUFS", "No buffer space available"),
 390 #endif
 391 #if defined (EISCONN)
 392   ENTRY(EISCONN, "EISCONN", "Transport endpoint is already connected"),
 393 #endif
 394 #if defined (ENOTCONN)
 395   ENTRY(ENOTCONN, "ENOTCONN", "Transport endpoint is not connected"),
 396 #endif
 397 #if defined (ESHUTDOWN)
 398   ENTRY(ESHUTDOWN, "ESHUTDOWN", "Cannot send after transport endpoint shutdown"),
 399 #endif
 400 #if defined (ETOOMANYREFS)
 401   ENTRY(ETOOMANYREFS, "ETOOMANYREFS", "Too many references: cannot splice"),
 402 #endif
 403 #if defined (ETIMEDOUT)
 404   ENTRY(ETIMEDOUT, "ETIMEDOUT", "Connection timed out"),
 405 #endif
 406 #if defined (ECONNREFUSED)
 407   ENTRY(ECONNREFUSED, "ECONNREFUSED", "Connection refused"),
 408 #endif
 409 #if defined (EHOSTDOWN)
 410   ENTRY(EHOSTDOWN, "EHOSTDOWN", "Host is down"),
 411 #endif
 412 #if defined (EHOSTUNREACH)
 413   ENTRY(EHOSTUNREACH, "EHOSTUNREACH", "No route to host"),
 414 #endif
 415 #if defined (EALREADY)
 416   ENTRY(EALREADY, "EALREADY", "Operation already in progress"),
 417 #endif
 418 #if defined (EINPROGRESS)
 419   ENTRY(EINPROGRESS, "EINPROGRESS", "Operation now in progress"),
 420 #endif
 421 #if defined (ESTALE)
 422   ENTRY(ESTALE, "ESTALE", "Stale NFS file handle"),
 423 #endif
 424 #if defined (EUCLEAN)
 425   ENTRY(EUCLEAN, "EUCLEAN", "Structure needs cleaning"),
 426 #endif
 427 #if defined (ENOTNAM)
 428   ENTRY(ENOTNAM, "ENOTNAM", "Not a XENIX named type file"),
 429 #endif
 430 #if defined (ENAVAIL)
 431   ENTRY(ENAVAIL, "ENAVAIL", "No XENIX semaphores available"),
 432 #endif
 433 #if defined (EISNAM)
 434   ENTRY(EISNAM, "EISNAM", "Is a named type file"),
 435 #endif
 436 #if defined (EREMOTEIO)
 437   ENTRY(EREMOTEIO, "EREMOTEIO", "Remote I/O error"),
 438 #endif
 439   ENTRY(0, NULL, NULL)
 440 };
 441
 442 #ifdef EVMSERR
 443 /* This is not in the table, because the numeric value of EVMSERR (32767)
 444    lies outside the range of sys_errlist[].  */
 445 static struct { int value; const char *name, *msg; }
 446   evmserr = { EVMSERR, "EVMSERR", "VMS-specific error" };
 447 #endif
 448
 449 /* Translation table allocated and initialized at runtime.  Indexed by the
 450    errno value to find the equivalent symbolic value. */
 451
 452 static const char **error_names;
 453 static int num_error_names = 0;
 454
 455 /* Translation table allocated and initialized at runtime, if it does not
 456    already exist in the host environment.  Indexed by the errno value to find
 457    the descriptive string.
 458
 459    We don't export it for use in other modules because even though it has the
 460    same name, it differs from other implementations in that it is dynamically
 461    initialized rather than statically initialized. */
 462
 463 #ifndef HAVE_SYS_ERRLIST
 464
 465 static int sys_nerr;
 466 static const char **sys_errlist;
 467
 468 #else
 469
 470 extern int sys_nerr;
 471 extern char *sys_errlist[];
 472
 473 #endif
 474
 475
 476 /*
 477
 478 NAME
 479
 480         init_error_tables -- initialize the name and message tables
 481
 482 SYNOPSIS
 483
 484         static void init_error_tables ();
 485
 486 DESCRIPTION
 487
 488         Using the error_table, which is initialized at compile time, generate
 489         the error_names and the sys_errlist (if needed) tables, which are
 490         indexed at runtime by a specific errno value.
 491
 492 BUGS
 493
 494         The initialization of the tables may fail under low memory conditions,
 495         in which case we don't do anything particularly useful, but we don't
 496         bomb either.  Who knows, it might succeed at a later point if we free
 497         some memory in the meantime.  In any case, the other routines know
 498         how to deal with lack of a table after trying to initialize it.  This
 499         may or may not be considered to be a bug, that we don't specifically
 500         warn about this particular failure mode.
 501
 502 */
 503
 504 static void
 505 init_error_tables ()
 506 {
 507   const struct error_info *eip;
 508   int nbytes;
 509
 510   /* If we haven't already scanned the error_table once to find the maximum
 511      errno value, then go find it now. */
 512
 513   if (num_error_names == 0)
 514     {
 515       for (eip = error_table; eip -> name != NULL; eip++)
 516         {
 517           if (eip -> value >= num_error_names)
 518             {
 519               num_error_names = eip -> value + 1;
 520             }
 521         }
 522     }
 523
 524   /* Now attempt to allocate the error_names table, zero it out, and then
 525      initialize it from the statically initialized error_table. */
 526
 527   if (error_names == NULL)
 528     {
 529       nbytes = num_error_names * sizeof (char *);
 530       if ((error_names = (const char **) malloc (nbytes)) != NULL)
 531         {
 532           memset (error_names, 0, nbytes);
 533           for (eip = error_table; eip -> name != NULL; eip++)
 534             {
 535               error_names[eip -> value] = eip -> name;
 536             }
 537         }
 538     }
 539
 540 #ifndef HAVE_SYS_ERRLIST
 541
 542   /* Now attempt to allocate the sys_errlist table, zero it out, and then
 543      initialize it from the statically initialized error_table. */
 544
 545   if (sys_errlist == NULL)
 546     {
 547       nbytes = num_error_names * sizeof (char *);
 548       if ((sys_errlist = (const char **) malloc (nbytes)) != NULL)
 549         {
 550           memset (sys_errlist, 0, nbytes);
 551           sys_nerr = num_error_names;
 552           for (eip = error_table; eip -> name != NULL; eip++)
 553             {
 554               sys_errlist[eip -> value] = eip -> msg;
 555             }
 556         }
 557     }
 558
 559 #endif
 560
 561 }
 562
 563 /*
 564
 565
 566 @deftypefn Extension int errno_max (void)
 567
 568 Returns the maximum @code{errno} value for which a corresponding
 569 symbolic name or message is available.  Note that in the case where we
 570 use the @code{sys_errlist} supplied by the system, it is possible for
 571 there to be more symbolic names than messages, or vice versa.  In
 572 fact, the manual page for @code{perror(3C)} explicitly warns that one
 573 should check the size of the table (@code{sys_nerr}) before indexing
 574 it, since new error codes may be added to the system before they are
 575 added to the table.  Thus @code{sys_nerr} might be smaller than value
 576 implied by the largest @code{errno} value defined in @code{<errno.h>}.
 577
 578 We return the maximum value that can be used to obtain a meaningful
 579 symbolic name or message.
 580
 581 @end deftypefn
 582
 583 */
 584
 585 int
 586 errno_max ()
 587 {
 588   int maxsize;
 589
 590   if (error_names == NULL)
 591     {
 592       init_error_tables ();
 593     }
 594   maxsize = MAX (sys_nerr, num_error_names);
 595   return (maxsize - 1);
 596 }
 597
 598 #ifndef HAVE_STRERROR
 599
 600 /*
 601
 602 @deftypefn Supplemental char* strerror (int @var{errnoval})
 603
 604 Maps an @code{errno} number to an error message string, the contents
 605 of which are implementation defined.  On systems which have the
 606 external variables @code{sys_nerr} and @code{sys_errlist}, these
 607 strings will be the same as the ones used by @code{perror}.
 608
 609 If the supplied error number is within the valid range of indices for
 610 the @code{sys_errlist}, but no message is available for the particular
 611 error number, then returns the string @samp{Error @var{num}}, where
 612 @var{num} is the error number.
 613
 614 If the supplied error number is not a valid index into
 615 @code{sys_errlist}, returns @code{NULL}.
 616
 617 The returned string is only guaranteed to be valid only until the
 618 next call to @code{strerror}.
 619
 620 @end deftypefn
 621
 622 */
 623
 624 char *
 625 strerror (errnoval)
 626   int errnoval;
 627 {
 628   const char *msg;
 629   static char buf[32];
 630
 631 #ifndef HAVE_SYS_ERRLIST
 632
 633   if (error_names == NULL)
 634     {
 635       init_error_tables ();
 636     }
 637
 638 #endif
 639
 640   if ((errnoval < 0) || (errnoval >= sys_nerr))
 641     {
 642 #ifdef EVMSERR
 643       if (errnoval == evmserr.value)
 644         msg = evmserr.msg;
 645       else
 646 #endif
 647       /* Out of range, just return NULL */
 648       msg = NULL;
 649     }
 650   else if ((sys_errlist == NULL) || (sys_errlist[errnoval] == NULL))
 651     {
 652       /* In range, but no sys_errlist or no entry at this index. */
 653       sprintf (buf, "Error %d", errnoval);
 654       msg = buf;
 655     }
 656   else
 657     {
 658       /* In range, and a valid message.  Just return the message. */
 659       msg = (char *) sys_errlist[errnoval];
 660     }
 661
 662   return (msg);
 663 }
 664
 665 #endif  /* ! HAVE_STRERROR */
 666
 667
 668 /*
 669
 670 @deftypefn Replacement {const char*} strerrno (int @var{errnum})
 671
 672 Given an error number returned from a system call (typically returned
 673 in @code{errno}), returns a pointer to a string containing the
 674 symbolic name of that error number, as found in @code{<errno.h>}.
 675
 676 If the supplied error number is within the valid range of indices for
 677 symbolic names, but no name is available for the particular error
 678 number, then returns the string @samp{Error @var{num}}, where @var{num}
 679 is the error number.
 680
 681 If the supplied error number is not within the range of valid
 682 indices, then returns @code{NULL}.
 683
 684 The contents of the location pointed to are only guaranteed to be
 685 valid until the next call to @code{strerrno}.
 686
 687 @end deftypefn
 688
 689 */
 690
 691 const char *
 692 strerrno (errnoval)
 693   int errnoval;
 694 {
 695   const char *name;
 696   static char buf[32];
 697
 698   if (error_names == NULL)
 699     {
 700       init_error_tables ();
 701     }
 702
 703   if ((errnoval < 0) || (errnoval >= num_error_names))
 704     {
 705 #ifdef EVMSERR
 706       if (errnoval == evmserr.value)
 707         name = evmserr.name;
 708       else
 709 #endif
 710       /* Out of range, just return NULL */
 711       name = NULL;
 712     }
 713   else if ((error_names == NULL) || (error_names[errnoval] == NULL))
 714     {
 715       /* In range, but no error_names or no entry at this index. */
 716       sprintf (buf, "Error %d", errnoval);
 717       name = (const char *) buf;
 718     }
 719   else
 720     {
 721       /* In range, and a valid name.  Just return the name. */
 722       name = error_names[errnoval];
 723     }
 724
 725   return (name);
 726 }
 727
 728 /*
 729
 730 @deftypefn Extension int strtoerrno (const char *@var{name})
 731
 732 Given the symbolic name of a error number (e.g., @code{EACCES}), map it
 733 to an errno value.  If no translation is found, returns 0.
 734
 735 @end deftypefn
 736
 737 */
 738
 739 int
 740 strtoerrno (name)
 741      const char *name;
 742 {
 743   int errnoval = 0;
 744
 745   if (name != NULL)
 746     {
 747       if (error_names == NULL)
 748         {
 749           init_error_tables ();
 750         }
 751       for (errnoval = 0; errnoval < num_error_names; errnoval++)
 752         {
 753           if ((error_names[errnoval] != NULL) &&
 754               (strcmp (name, error_names[errnoval]) == 0))
 755             {
 756               break;
 757             }
 758         }
 759       if (errnoval == num_error_names)
 760         {
 761 #ifdef EVMSERR
 762           if (strcmp (name, evmserr.name) == 0)
 763             errnoval = evmserr.value;
 764           else
 765 #endif
 766           errnoval = 0;
 767         }
 768     }
 769   return (errnoval);
 770 }
 771
 772
 773 /* A simple little main that does nothing but print all the errno translations
 774    if MAIN is defined and this file is compiled and linked. */
 775
 776 #ifdef MAIN
 777
 778 #include <stdio.h>
 779
 780 int
 781 main ()
 782 {
 783   int errn;
 784   int errnmax;
 785   const char *name;
 786   const char *msg;
 787   char *strerror ();
 788
 789   errnmax = errno_max ();
 790   printf ("%d entries in names table.\n", num_error_names);
 791   printf ("%d entries in messages table.\n", sys_nerr);
 792   printf ("%d is max useful index.\n", errnmax);
 793
 794   /* Keep printing values until we get to the end of *both* tables, not
 795      *either* table.  Note that knowing the maximum useful index does *not*
 796      relieve us of the responsibility of testing the return pointer for
 797      NULL. */
 798
 799   for (errn = 0; errn <= errnmax; errn++)
 800     {
 801       name = strerrno (errn);
 802       name = (name == NULL) ? "<NULL>" : name;
 803       msg = strerror (errn);
 804       msg = (msg == NULL) ? "<NULL>" : msg;
 805       printf ("%-4d%-18s%s\n", errn, name, msg);
 806     }
 807
 808   return 0;
 809 }
 810
 811 #endif