source: trunk/binutils/libiberty/strerror.c@ 2828

Last change on this file since 2828 was 764, checked in by bird, 22 years ago

sys_errlist and sys_nerr shall not be in stdlib.h but stdio.h or errno.h!
  • Property cvs2svn:cvs-rev set to 1.3
  • Property svn:eol-style set to native
  • Property svn:executable set to *
File size: 20.7 KB
Line 
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
33extern PTR malloc ();
34#endif
35
36#ifdef HAVE_STRING_H
37#include <string.h>
38#else
39extern PTR memset ();
40#endif
41
42#ifndef MAX
43# define MAX(a,b) ((a) > (b) ? (a) : (b))
44#endif
45
46static 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
59struct 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
74static 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[]. */
445static 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
452static const char **error_names;
453static 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
465static int sys_nerr;
466static const char **sys_errlist;
467
468#else
469
470extern int sys_nerr;
471extern char *sys_errlist[];
472
473#endif
474
475
476/*
477
478NAME
479
480 init_error_tables -- initialize the name and message tables
481
482SYNOPSIS
483
484 static void init_error_tables ();
485
486DESCRIPTION
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
492BUGS
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
504static void
505init_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
568Returns the maximum @code{errno} value for which a corresponding
569symbolic name or message is available. Note that in the case where we
570use the @code{sys_errlist} supplied by the system, it is possible for
571there to be more symbolic names than messages, or vice versa. In
572fact, the manual page for @code{perror(3C)} explicitly warns that one
573should check the size of the table (@code{sys_nerr}) before indexing
574it, since new error codes may be added to the system before they are
575added to the table. Thus @code{sys_nerr} might be smaller than value
576implied by the largest @code{errno} value defined in @code{<errno.h>}.
577
578We return the maximum value that can be used to obtain a meaningful
579symbolic name or message.
580
581@end deftypefn
582
583*/
584
585int
586errno_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
604Maps an @code{errno} number to an error message string, the contents
605of which are implementation defined. On systems which have the
606external variables @code{sys_nerr} and @code{sys_errlist}, these
607strings will be the same as the ones used by @code{perror}.
608
609If the supplied error number is within the valid range of indices for
610the @code{sys_errlist}, but no message is available for the particular
611error number, then returns the string @samp{Error @var{num}}, where
612@var{num} is the error number.
613
614If the supplied error number is not a valid index into
615@code{sys_errlist}, returns @code{NULL}.
616
617The returned string is only guaranteed to be valid only until the
618next call to @code{strerror}.
619
620@end deftypefn
621
622*/
623
624char *
625strerror (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
672Given an error number returned from a system call (typically returned
673in @code{errno}), returns a pointer to a string containing the
674symbolic name of that error number, as found in @code{<errno.h>}.
675
676If the supplied error number is within the valid range of indices for
677symbolic names, but no name is available for the particular error
678number, then returns the string @samp{Error @var{num}}, where @var{num}
679is the error number.
680
681If the supplied error number is not within the range of valid
682indices, then returns @code{NULL}.
683
684The contents of the location pointed to are only guaranteed to be
685valid until the next call to @code{strerrno}.
686
687@end deftypefn
688
689*/
690
691const char *
692strerrno (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
732Given the symbolic name of a error number (e.g., @code{EACCES}), map it
733to an errno value. If no translation is found, returns 0.
734
735@end deftypefn
736
737*/
738
739int
740strtoerrno (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
780int
781main ()
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
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