| Error Constant | Message |
| E2BIG | Arg list too long |
| EACCES | Permission denied |
| EADDRINUSE | Address already in use |
| EADDRNOTAVAIL | Cannot assign requested address |
| EADV | Advertise error |
| EAFNOSUPPORT | Address family not supported by protocol |
| EAGAIN | Try again |
| EALREADY | Operation already in progress |
| EBADE | Invalid exchange |
| EBADF | Bad file number |
| EBADFD | File descriptor in bad state |
| EBADMSG | Not a data message |
| EBADR | Invalid request descriptor |
| EBADRQC | Invalid request code |
| EBADSLT | Invalid slot |
| EBFONT | Bad font file format |
| EBUSY | Device or resource busy |
| ECHILD | No child processes |
| ECHRNG | Channel number out of range |
| ECOMM | Communication error on send |
| ECONNABORTED | Software caused connection abort |
| ECONNREFUSED | Connection refused |
| ECONNRESET | Connection reset by peer |
| EDEADLK | Resource deadlock would occur |
| EDESTADDRREQ | Destination address required |
| EDOM | Math argument out of domain of func |
| EDOTDOT | RFS specific error |
| EDQUOT | Quota exceeded |
| EEXIST | File exists |
| EFAULT | Bad address |
| EFBIG | File too large |
| EHOSTDOWN | Host is down |
| EHOSTUNREACH | No route to host |
| EIDRM | Identifier removed |
| EILSEQ | Illegal byte sequence |
| EINPROGRESS | Operation now in progress |
| EINTR | Interrupted system call |
| EINVAL | Invalid argument |
| EIO | I/O error |
| EISCONN | Transport endpoint is already connected |
| EISDIR | Is a directory |
| EISNAM | Is a named type file |
| EL2HLT | Level 2 halted |
| EL2NSYNC | Level 2 not synchronized |
| EL3HLT | Level 3 halted |
| EL3RST | Level 3 reset |
| ELIBACC | Cannot access a needed shared library |
| ELIBBAD | Accessing a corrupted shared library |
| ELIBEXEC | Cannot exec a shared library directly |
| ELIBMAX | Attempting to link in too many shared libraries |
| ELIBSCN | .lib section in a.out corrupted |
| ELNRNG | Link number out of range |
| ELOOP | Too many symbolic links encountered |
| EMEDIUMTYPE | Wrong medium type |
| EMFILE | Too many open files |
| EMLINK | Too many links |
| EMSGSIZE | Message too long |
| EMULTIHOP | Multihop attempted |
| ENAMETOOLONG | Filename too long |
| ENAVAIL | No XENIX semaphores available |
| ENETDOWN | Network is down |
| ENETRESET | Network dropped connection because of reset |
| ENETUNREACH | Network is unreachable |
| ENFILE | File table overflow |
| ENOANO | No anode |
| ENOBUFS | No buffer space available |
| ENOCSI | No CSI structure available |
| ENODATA | No data available |
| ENODEV | No such device |
| ENOENT | No such file or directory |
| ENOEXEC | Exec format error |
| ENOLCK | No record locks available |
| ENOLINK | Link has been severed |
| ENOMEDIUM | No medium found |
| ENOMEM | Out of memory |
| ENOMSG | No message of desired type |
| ENONET | Machine is not on the network |
| ENOPKG | Package not installed |
| ENOPROTOOPT | Protocol not available |
| ENOSPC | No space left on device |
| ENOSR | Out of streams resources |
| ENOSTR | Device not a stream |
| ENOSYS | Function not implemented |
| ENOTBLK | Block device required |
| ENOTCONN | Transport endpoint is not connected |
| ENOTDIR | Not a directory |
| ENOTEMPTY | Directory not empty |
| ENOTNAM | Not a XENIX named type file |
| ENOTSOCK | Socket operation on nonsocket |
| ENOTTY | Not a typewriter |
| ENOTUNIQ | Name not unique on network |
| ENXIO | No such device or address |
| EOPNOTSUPP | Operation not supported on transport endpoint |
| EOVERFLOW | Value too large for defined data type |
| EPERM | Operation not permitted |
| EPFNOSUPPORT | Protocol family not supported |
| EPIPE | Broken pipe |
| EPROTO | Protocol error |
| EPROTONOSUPPORT | Protocol not supported |
| EPROTOTYPE | Protocol wrong type for socket |
| ERANGE | Math result not representable |
| EREMCHG | Remote address changed |
| EREMOTE | Object is remote |
| EREMOTEIO | Remote I/O error |
| ERESTART | Interrupted system call should be restarted |
| EROFS | Read-only filesystem |
| ESHUTDOWN | Cannot send after transport endpoint shutdown |
| ESOCKTNOSUPPORT | Socket type not supported |
| ESPIPE | Illegal seek |
| ESRCH | No such process |
| ESRMNT | Srmount error |
| ESTALE | Stale NFS filehandle |
| ESTRPIPE | Streams pipe error |
| ETIME | Timer expired |
| ETIMEDOUT | Connection timed out |
| ETOOMANYREFS | Too many references; cannot splice |
| ETXTBSY | Text file busy |
| EUCLEAN | Structure needs cleaning |
| EUNATCH | Protocol driver not attached |
| EUSERS | Too many users |
| EWOULDBLOCK | Operation would block |
| EXDEV | Cross-device link |
| EXFULL | Exchange full |
