Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

AF_UNIX (integer)
AF_INET (integer)
AF_INET6 (integer)
Only available if compiled with IPv6 support.
SOCK_STREAM (integer)
SOCK_DGRAM (integer)
SOCK_RAW (integer)
SOCK_SEQPACKET (integer)
SOCK_RDM (integer)
MSG_OOB (integer)
MSG_WAITALL (integer)
MSG_PEEK (integer)
MSG_DONTROUTE (integer)
MSG_EOR (integer)
Not available on Windows platforms.
MSG_EOF (integer)
Not available on Windows platforms.
SO_DEBUG (integer)
SO_REUSEADDR (integer)
SO_REUSEPORT (integer)
This constant is only available in PHP 5.4.10 or later on platforms that support the SO_REUSEPORT socket option: this includes Mac OS X and FreeBSD, but does not include Linux or Windows.
SO_KEEPALIVE (integer)
SO_DONTROUTE (integer)
SO_LINGER (integer)
SO_BROADCAST (integer)
SO_OOBINLINE (integer)
SO_SNDBUF (integer)
SO_RCVBUF (integer)
SO_SNDLOWAT (integer)
SO_RCVLOWAT (integer)
SO_SNDTIMEO (integer)
SO_RCVTIMEO (integer)
SO_TYPE (integer)
SO_ERROR (integer)
TCP_NODELAY (integer)
Used to disable Nagle TCP algorithm. Added in PHP 5.2.7.
SOL_SOCKET (integer)
PHP_NORMAL_READ (integer)
PHP_BINARY_READ (integer)
SOL_TCP (integer)
SOL_UDP (integer)

The following constants are defined under Windows and UNIX-like platforms. Each constant is only defined if their equal is available on the platform.

SOCKET_EINTR (integer)
Interrupted system call.
SOCKET_EBADF (integer)
Bad file number.
SOCKET_EACCES (integer)
Permission denied.
SOCKET_EFAULT (integer)
Bad address.
SOCKET_EINVAL (integer)
Invalid argument.
SOCKET_EMFILE (integer)
Too many open files.
SOCKET_ENAMETOOLONG (integer)
File name too long.
SOCKET_ENOTEMPTY (integer)
Directory not empty.
SOCKET_ELOOP (integer)
Too many symbolic links encountered.
SOCKET_EWOULDBLOCK (integer)
Operation would block.
SOCKET_EREMOTE (integer)
Object is remote.
SOCKET_EUSERS (integer)
Too many users.
SOCKET_ENOTSOCK (integer)
Socket operation on non-socket.
SOCKET_EDESTADDRREQ (integer)
Destination address required.
SOCKET_EMSGSIZE (integer)
Message too long.
SOCKET_EPROTOTYPE (integer)
Protocol wrong type for socket.
SOCKET_EPROTONOSUPPORT (integer)
Protocol not supported.
SOCKET_ESOCKTNOSUPPORT (integer)
Socket type not supported.
SOCKET_EOPNOTSUPP (integer)
Operation not supported on transport endpoint.
SOCKET_EPFNOSUPPORT (integer)
Protocol family not supported.
SOCKET_EAFNOSUPPORT (integer)
Address family not supported by protocol.
SOCKET_EADDRNOTAVAIL (integer)
Cannot assign requested address.
SOCKET_ENETDOWN (integer)
Network is down.
SOCKET_ENETUNREACH (integer)
Network is unreachable.
SOCKET_ENETRESET (integer)
Network dropped connection because of reset.
SOCKET_ECONNABORTED (integer)
Software caused connection abort.
SOCKET_ECONNRESET (integer)
Connection reset by peer.
SOCKET_ENOBUFS (integer)
No buffer space available.
SOCKET_EISCONN (integer)
Transport endpoint is already connected.
SOCKET_ENOTCONN (integer)
Transport endpoint is not connected.
SOCKET_ESHUTDOWN (integer)
Cannot send after transport endpoint shutdown.
SOCKET_ETIMEDOUT (integer)
Connection timed out.
SOCKET_ECONNREFUSED (integer)
Connection refused.
SOCKET_EHOSTDOWN (integer)
Host is down.
SOCKET_EHOSTUNREACH (integer)
No route to host.
SOCKET_EALREADY (integer)
Operation already in progress.
SOCKET_EINPROGRESS (integer)
Operation now in progress.

The following constants are only defined under Windows.

SOCKET_ENOPROTOOPT (integer)
SOCKET_EADDRINUSE (integer)
SOCKET_ETOOMYREFS (integer)
SOCKET_EPROCLIM (integer)
SOCKET_EDUOT (integer)
SOCKET_ESTALE (integer)
SOCKET_EDISCON (integer)
SOCKET_SYSNOTREADY (integer)
SOCKET_VERNOTSUPPORTED (integer)
SOCKET_NOTINITIALISED (integer)
SOCKET_HOST_NOT_FOUND (integer)
SOCKET_TRY_AGAIN (integer)
SOCKET_NO_RECOVERY (integer)
SOCKET_NO_DATA (integer)
SOCKET_NO_ADDRESS (integer)

The following constants are only available on UNIX-like platforms. Each constant is only defined if their equal is available on the platform.

SOCKET_EPERM (integer)
Operation not permitted.
SOCKET_ENOENT (integer)
No such file or directory.
SOCKET_EIO (integer)
I/O error.
SOCKET_ENXIO (integer)
No such device or address.
SOCKET_E2BIG (integer)
Arg list too long.
SOCKET_EAGAIN (integer)
Try again.
SOCKET_ENOMEM (integer)
Out of memory.
SOCKET_ENOTBLK (integer)
Block device required.
SOCKET_EBUSY (integer)
Device or resource busy.
SOCKET_EEXIST (integer)
File exists.
SOCKET_EXDEV (integer)
Cross-device link.
SOCKET_ENODEV (integer)
No such device.
SOCKET_ENOTDIR (integer)
Not a directory.
SOCKET_EISDIR (integer)
Is a directory.
SOCKET_ENFILE (integer)
File table overflow.
SOCKET_ENOTTY (integer)
Not a typewriter.
SOCKET_ENOSPC (integer)
No space left on device.
SOCKET_ESPIPE (integer)
Illegal seek.
SOCKET_EROFS (integer)
Read-only file system.
Too many links.
SOCKET_EPIPE (integer)
Broken pipe.
SOCKET_ENOLCK (integer)
No record locks available.
SOCKET_ENOSYS (integer)
Function not implemented.
SOCKET_ENOMSG (integer)
No message of desired type.
SOCKET_EIDRM (integer)
Identifier removed.
SOCKET_ECHRNG (integer)
Channel number out of range.
SOCKET_EL2NSYNC (integer)
Level 2 not synchronized.
SOCKET_EL3HLT (integer)
Level 3 halted.
SOCKET_EL3RST (integer)
Level 3 reset.
SOCKET_ELNRNG (integer)
Link number out of range.
SOCKET_EUNATCH (integer)
Protocol driver not attached.
SOCKET_ENOCSI (integer)
No CSI structure available.
SOCKET_EL2HLT (integer)
Level 2 halted.
SOCKET_EBADE (integer)
Invalid exchange.
SOCKET_EBADR (integer)
Invalid request descriptor.
SOCKET_EXFULL (integer)
Exchange full.
SOCKET_ENOANO (integer)
No anode.
SOCKET_EBADRQC (integer)
Invalid request code.
SOCKET_EBADSLT (integer)
Invalid slot.
SOCKET_ENOSTR (integer)
Device not a stream.
SOCKET_ENODATA (integer)
No data available.
SOCKET_ETIME (integer)
Timer expired.
SOCKET_ENOSR (integer)
Out of streams resources.
SOCKET_ENONET (integer)
Machine is not on the network.
Link has been severed.
SOCKET_EADV (integer)
Advertise error.
SOCKET_ESRMNT (integer)
Srmount error.
SOCKET_ECOMM (integer)
Communication error on send.
SOCKET_EPROTO (integer)
Protocol error.
SOCKET_EMULTIHOP (integer)
Multihop attempted.
SOCKET_EBADMSG (integer)
Not a data message.
SOCKET_ENOTUNIQ (integer)
Name not unique on network.
SOCKET_EBADFD (integer)
File descriptor in bad state.
SOCKET_EREMCHG (integer)
Remote address changed.
SOCKET_ERESTART (integer)
Interrupted system call should be restarted.
SOCKET_ESTRPIPE (integer)
Streams pipe error.
SOCKET_EPROTOOPT (integer)
Protocol not available.
SOCKET_ADDRINUSE (integer)
Address already in use.
SOCKET_ETOOMANYREFS (integer)
Too many references: cannot splice.
SOCKET_EISNAM (integer)
Is a named type file.
SOCKET_EREMOTEIO (integer)
Remote I/O error.
SOCKET_EDQUOT (integer)
Quota exceeded.
SOCKET_ENOMEDIUM (integer)
No medium found.
SOCKET_EMEDIUMTYPE (integer)
Wrong medium type.