Error numbers

There are two incompatibilities in errnos:

• errnos have different values on each system (see ``Errors with different values'')

• the same calls on each system can generate errors that are not generated on the other system (see ``System calls with different error returns'')

Errors with different values

There are three classs of error numbers with different values on UnixWare 7 and SCO OpenServer:

• Errors that are semantically the same on both systems but have different error numbers on each system; these errors are directly translated on UnixWare 7 (for SCO OpenServer binaries) by the kernel and on SCO OpenServer (for binaries created using the UnixWare 7 UDK) by the Binary Compatibility Module (BCM) for SCO OpenServer. See ``Errors that have different errnos on each system''.

• Errors on UnixWare 7 (and SCO UnixWare 2.1.X) that are not on SCO OpenServer; these errors are translated by the code for each system call on UnixWare 7, so that an error appropriate for SCO OpenServer applications is returned. UDK applications running on SCO OpenServer will not see these errors; the behavior of portable programs should not be made to depend on the target system returning these errors. See ``Errors on UnixWare 7 but not SCO OpenServer''.

• Errors on SCO OpenServer that are not on UnixWare 7 (and SCO UnixWare 2.1.X); the resolution of the incompatibilities varies depending on the system call, and is presented in ``Errors on SCO OpenServer but not UnixWare 7''.

Errors that have different errnos on each system

Error mnemonic	UnixWare 7 errno	SCO OpenServer errno
ELOOP	90	150
ERESTART	91	152
ESTRPIPE	92	153
ENOTEMPTY	93	145
ENOSTOCK	95	93
EDESTADDRREQ	96	94
EMSGSIZE	97	95
EPROTOTYPE	98	96
ENOPROTOOPT	99	118
EPROTONOSUPPORT	120	97
ESOCKTNOSUPPORT	121	98
EOPNOTSUPP	122	99
EPFNOSUPPORT	123	100
EAFNOSUPPORT	124	101
EADDRINUSE	125	102
EADDRNOTAVAIL	126	103
ENETDOWN	127	104
ENETUNREACH	128	105
ENETRESET	129	106
ECONNABORTED	130	107
ECONNRESET	131	108
ENOBUFS	132	109
EISCONN	133	110
ENOTCONN	134	111
ESHUTDOWN	143	112
ETOOMANYREFS	144	113
ETIMEDOUT	145	114
ECONNREFUSED	146	115
EHOSTDOWN	147	116
EHOSTUNREACH	148	117
EWOULDBLOCK	11(EAGAIN)	90
EALREADY	149	92
EINPPROGRESS	150	91

Errors on UnixWare 7 but not SCO OpenServer

Mnemonic	UnixWare 7 #	SCO OpenServer #
ECLNRACE	59
ENOLOAD	152
ERELOC	153
ENOMATCH	154
EBADVER	156
ECONFIG	157
ECANCELED	158
EUSERS	94
ENOTAUTH	160
ELKBUSY	170
Olivetti	200-223

Errors on SCO OpenServer but not UnixWare 7

Mnemonic	SCO OpenServer #	UnixWare 7 #
ELBIN	75
EDOTDOT	76

System calls with different error returns

The table below shows the errors returned for various system calls that are different between UnixWare 7 and SCO OpenServer. See the ``System call compatibility tables'' for each system call listed for the detailed resolution of the error incompatibility (if you are viewing this document online, click on the system call name in the left-most column to go to the appropriate table).

Errors generated on one system and not the other.
System call	extra UnixWare 7 errs	extra SCO OpenServer errs
access	EFAULT, ELOOP	ETXTBSY
chdir	EIO
chroot	EACCESS, ELOOP, ENAMETOOLONG
creat	ELOOP,ENAMETOOLONG
exec	ENOLOAD, ENOTDIR	ETXTBSY
fchdir	EIO
fcntl	EFAULT, EIO, EINVAL, EOVERFLOW
fork	EINTR
fsync	ENOLINK
ftruncate		EAGAIN
link	ENAMETOOLONG
lseek	ENOSYS
mkdir	ENAMETOOLONG, ENOSPC
mknod	EINVAL, ELOOP, ENAMETOOLONG
mount	EACCESS, ENOLOAD, ELOOP, ENAMETOOLONG
msgctl(ipcmsg)	EOVERFLOW
msgsnd/msgrcv(ipcmsg)	EINTR, EIDRM
nice	EINVAL
ptrace		EINVAL, EPERM
readlink	ENOSYS
rmdir	ELOOP, ENAMETOOLONG	EINVAL
semctl(semsys)	EOVERFLOW, EFAULT
semop(semsys)	EINTR
shmctl(shmsys)		ENOSYS
shmget(shmsys)		ENOSYS
symlink	ENOSYS, EIO	EINVAL
sysacct	ELOOP, ENAMETOOLONG
umount	ELOOP, ENAMETOOLONG
unlink	EFAULT, ELOOP	ETXTBSY
utime	EFAULT, ELOOP