On Sun, Mar 15, 2009 at 4:20 AM, Steve Graegert <graegerts@xxxxxxxxx> wrote:
> Angel,
>
> The following code snippet should do it. It basically sets errno
> manually and outputs the associated error message.
>
> --- BEGIN ---
>
> #define _ALL_SOURCE
>
> #include <stdio.h>
> #include <errno.h> /* for _MAX_ERRNO */
>
> int main(void) {
> int i;
> extern int errno;
>
> for (i = 0; i < MAX_ERRNO; i++) {
> fprintf(stderr, "%3d", i);
> errno = i;
> perror(" ");
> }
>
> return (0);
> }
>
> --- END ---
>
> \Steve
>
> --
>
> Steve Graegert
> www.graegert.com
>
>
>
> On Sun, Mar 15, 2009 at 11:46 AM, Angel Tsankov
> <fn42551@xxxxxxxxxxxxxxxx> wrote:
>> Hello,
>>
>> Is there a function which returns the description of an errno value and, if
>> so, which is it?
>>
>> Regards,
>> Angel Tsankov
>>
A little fancier snippet that I wrote years ago to deal with programs
that only output an errno number and no description is this:
/* error.c : utility for looking up errno error numbers */
/* original version: 2006 June 27
* 2006 June 29 -- version 1.04
* contributors: Jon Mayo <jon.mayo@xxxxxxx>
* No copyright claimed -- Public Domain */
/* TODO: convert error strings into error numbers/names */
#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define T(x) if(e==(x)) return #x
static const char **id_lookup_table;
static unsigned id_max;
static const char *err_id(int e) {
#ifdef EPERM
T(EPERM);
#endif
#ifdef ENOENT
T(ENOENT);
#endif
#ifdef ESRCH
T(ESRCH);
#endif
#ifdef EINTR
T(EINTR);
#endif
#ifdef EIO
T(EIO);
#endif
#ifdef ENXIO
T(ENXIO);
#endif
#ifdef E2BIG
T(E2BIG);
#endif
#ifdef ENOEXEC
T(ENOEXEC);
#endif
#ifdef EBADF
T(EBADF);
#endif
#ifdef ECHILD
T(ECHILD);
#endif
#ifdef EAGAIN
T(EAGAIN);
#endif
#ifdef ENOMEM
T(ENOMEM);
#endif
#ifdef EACCES
T(EACCES);
#endif
#ifdef EFAULT
T(EFAULT);
#endif
#ifdef ENOTBLK
T(ENOTBLK);
#endif
#ifdef EBUSY
T(EBUSY);
#endif
#ifdef EEXIST
T(EEXIST);
#endif
#ifdef EXDEV
T(EXDEV);
#endif
#ifdef ENODEV
T(ENODEV);
#endif
#ifdef ENOTDIR
T(ENOTDIR);
#endif
#ifdef EISDIR
T(EISDIR);
#endif
#ifdef EINVAL
T(EINVAL);
#endif
#ifdef ENFILE
T(ENFILE);
#endif
#ifdef EMFILE
T(EMFILE);
#endif
#ifdef ENOTTY
T(ENOTTY);
#endif
#ifdef ETXTBSY
T(ETXTBSY);
#endif
#ifdef EFBIG
T(EFBIG);
#endif
#ifdef ENOSPC
T(ENOSPC);
#endif
#ifdef ESPIPE
T(ESPIPE);
#endif
#ifdef EROFS
T(EROFS);
#endif
#ifdef EMLINK
T(EMLINK);
#endif
#ifdef EPIPE
T(EPIPE);
#endif
#ifdef EDOM
T(EDOM);
#endif
#ifdef ERANGE
T(ERANGE);
#endif
#ifdef EDEADLK
T(EDEADLK);
#endif
#ifdef ENAMETOOLONG
T(ENAMETOOLONG);
#endif
#ifdef ENOLCK
T(ENOLCK);
#endif
#ifdef ENOSYS
T(ENOSYS);
#endif
#ifdef ENOTEMPTY
T(ENOTEMPTY);
#endif
#ifdef ELOOP
T(ELOOP);
#endif
#ifdef EWOULDBLOCK
T(EWOULDBLOCK);
#endif
#ifdef ENOMSG
T(ENOMSG);
#endif
#ifdef EIDRM
T(EIDRM);
#endif
#ifdef ECHRNG
T(ECHRNG);
#endif
#ifdef EL2NSYNC
T(EL2NSYNC);
#endif
#ifdef EL3HLT
T(EL3HLT);
#endif
#ifdef EL3RST
T(EL3RST);
#endif
#ifdef ELNRNG
T(ELNRNG);
#endif
#ifdef EUNATCH
T(EUNATCH);
#endif
#ifdef ENOCSI
T(ENOCSI);
#endif
#ifdef EL2HLT
T(EL2HLT);
#endif
#ifdef EBADE
T(EBADE);
#endif
#ifdef EBADR
T(EBADR);
#endif
#ifdef EXFULL
T(EXFULL);
#endif
#ifdef ENOANO
T(ENOANO);
#endif
#ifdef EBADRQC
T(EBADRQC);
#endif
#ifdef EBADSLT
T(EBADSLT);
#endif
#ifdef EDEADLOCK
T(EDEADLOCK);
#endif
#ifdef EBFONT
T(EBFONT);
#endif
#ifdef ENOSTR
T(ENOSTR);
#endif
#ifdef ENODATA
T(ENODATA);
#endif
#ifdef ETIME
T(ETIME);
#endif
#ifdef ENOSR
T(ENOSR);
#endif
#ifdef ENONET
T(ENONET);
#endif
#ifdef ENOPKG
T(ENOPKG);
#endif
#ifdef EREMOTE
T(EREMOTE);
#endif
#ifdef ENOLINK
T(ENOLINK);
#endif
#ifdef EADV
T(EADV);
#endif
#ifdef ESRMNT
T(ESRMNT);
#endif
#ifdef ECOMM
T(ECOMM);
#endif
#ifdef EPROTO
T(EPROTO);
#endif
#ifdef EMULTIHOP
T(EMULTIHOP);
#endif
#ifdef EDOTDOT
T(EDOTDOT);
#endif
#ifdef EBADMSG
T(EBADMSG);
#endif
#ifdef EOVERFLOW
T(EOVERFLOW);
#endif
#ifdef ENOTUNIQ
T(ENOTUNIQ);
#endif
#ifdef EBADFD
T(EBADFD);
#endif
#ifdef EREMCHG
T(EREMCHG);
#endif
#ifdef ELIBACC
T(ELIBACC);
#endif
#ifdef ELIBBAD
T(ELIBBAD);
#endif
#ifdef ELIBSCN
T(ELIBSCN);
#endif
#ifdef ELIBMAX
T(ELIBMAX);
#endif
#ifdef ELIBEXEC
T(ELIBEXEC);
#endif
#ifdef EILSEQ
T(EILSEQ);
#endif
#ifdef ERESTART
T(ERESTART);
#endif
#ifdef ESTRPIPE
T(ESTRPIPE);
#endif
#ifdef EUSERS
T(EUSERS);
#endif
#ifdef ENOTSOCK
T(ENOTSOCK);
#endif
#ifdef ETOOMANYREF
T(ETOOMANYREF);
#endif
#ifdef TADDRREQ
T(TADDRREQ);
#endif
#ifdef EMSGSIZE
T(EMSGSIZE);
#endif
#ifdef EPROTOTYPE
T(EPROTOTYPE);
#endif
#ifdef ENOPROTOOPT
T(ENOPROTOOPT);
#endif
#ifdef EPROTONOSUPPORT
T(EPROTONOSUPPORT);
#endif
#ifdef ESOCKTNOSUPPORT
T(ESOCKTNOSUPPORT);
#endif
#ifdef EOPNOTSUPP
T(EOPNOTSUPP);
#endif
#ifdef EPFNOSUPPORT
T(EPFNOSUPPORT);
#endif
#ifdef EAFNOSUPPORT
T(EAFNOSUPPORT);
#endif
#ifdef EADDRINUSE
T(EADDRINUSE);
#endif
#ifdef EADDRNOTAVAIL
T(EADDRNOTAVAIL);
#endif
#ifdef ENETDOWN
T(ENETDOWN);
#endif
#ifdef ENETUNREACH
T(ENETUNREACH);
#endif
#ifdef ENETRESET
T(ENETRESET);
#endif
#ifdef ECONNABORTED
T(ECONNABORTED);
#endif
#ifdef ECONNRESET
T(ECONNRESET);
#endif
#ifdef ENOBUFS
T(ENOBUFS);
#endif
#ifdef EISCONN
T(EISCONN);
#endif
#ifdef ENOTCONN
T(ENOTCONN);
#endif
#ifdef ESHUTDOWN
T(ESHUTDOWN);
#endif
#ifdef ETOOMANYREFS
T(ETOOMANYREFS);
#endif
#ifdef ECONNREFUSED
T(ECONNREFUSED);
#endif
#ifdef EHOSTDOWN
T(EHOSTDOWN);
#endif
#ifdef EHOSTUNREACH
T(EHOSTUNREACH);
#endif
#ifdef EALREADY
T(EALREADY);
#endif
#ifdef EINPROGRESS
T(EINPROGRESS);
#endif
#ifdef ESTALE
T(ESTALE);
#endif
#ifdef EUCLEAN
T(EUCLEAN);
#endif
#ifdef ENOTNAM
T(ENOTNAM);
#endif
#ifdef ENAVAIL
T(ENAVAIL);
#endif
#ifdef EISNAM
T(EISNAM);
#endif
#ifdef EREMOTEIO
T(EREMOTEIO);
#endif
#ifdef EDQUOT
T(EDQUOT);
#endif
#ifdef ENOMEDIUM
T(ENOMEDIUM);
#endif
#ifdef EMEDIUMTYPE
T(EMEDIUMTYPE);
#endif
#ifdef ECANCELED
T(ECANCELED);
#endif
#ifdef ENOKEY
T(ENOKEY);
#endif
#ifdef EKEYEXPIRED
T(EKEYEXPIRED);
#endif
#ifdef EKEYREVOKED
T(EKEYREVOKED);
#endif
#ifdef EKEYREJECTED
T(EKEYREJECTED);
#endif
return 0;
}
/* attempt to guess the largest error value. assume gaps of 100 means
that's the end of the list of errors */
static int guess_max(void) {
int i;
int miss_count;
for(i=0,miss_count=0;i<INT_MAX;i++) {
if(err_id(i)) {
miss_count=0;
} else {
miss_count++;
if(miss_count>100) break;
}
}
return i-miss_count;
}
static void init_id_lookup_table(void) {
int i;
id_max=guess_max();
id_lookup_table=calloc(sizeof *id_lookup_table, id_max+1);
for(i=0;i<=id_max;i++) {
id_lookup_table[i]=err_id(i);
}
}
static int lookup_id_str(const char *str) {
int i;
assert(id_lookup_table!=NULL);
assert(id_max>0);
for(i=0;i<=id_max;i++) {
if(id_lookup_table[i] && !strcmp(str, id_lookup_table[i])) {
return i;
}
}
return -1;
}
static void show_error(int e) {
const char *id;
id=err_id(e);
if(!id) id="???";
printf("%d:%s:%s\n", e, id, strerror(e));
}
int main(int argc, char **argv) {
if(argc==1) {
int max;
max=guess_max();
printf("max error: %d\n", max);
} else {
int i;
init_id_lookup_table();
for(i=1;i<argc;i++) {
int e;
char *endptr;
e=strtol(argv[i],&endptr,10);
if(!endptr || *endptr) {
e=lookup_id_str(argv[i]);
if(e<0) {
fprintf(stderr, "error '%s' unknown.\n", argv[i]);
continue;
}
}
if(e<0) e=-e;
show_error(e);
}
}
return 0;
}
/** END **/
--
Jon Mayo
<jon.mayo@xxxxxxxxx>
--
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