&reftitle.constants; &extension.constants; AF_UNIX (int) AF_INET (int) AF_INET6 (int) Only available if compiled with IPv6 support. SOCK_STREAM (int) SOCK_DGRAM (int) SOCK_RAW (int) SOCK_SEQPACKET (int) SOCK_RDM (int) MSG_OOB (int) MSG_WAITALL (int) MSG_PEEK (int) MSG_DONTROUTE (int) MSG_EOR (int) Not available on Windows platforms. MSG_EOF (int) Not available on Windows platforms. SO_DEBUG (int) SO_REUSEADDR (int) SO_REUSEPORT (int) This constant is only available on platforms that support the SO_REUSEPORT socket option: this includes macOS and FreeBSD, but does not include Linux or Windows. SO_KEEPALIVE (int) SO_DONTROUTE (int) SO_LINGER (int) SO_BROADCAST (int) SO_OOBINLINE (int) SO_SNDBUF (int) SO_RCVBUF (int) SO_SNDLOWAT (int) SO_RCVLOWAT (int) SO_SNDTIMEO (int) SO_RCVTIMEO (int) SO_TYPE (int) SO_ERROR (int) TCP_NODELAY (int) Used to disable Nagle TCP algorithm. SOL_SOCKET (int) PHP_NORMAL_READ (int) PHP_BINARY_READ (int) SOL_TCP (int) SOL_UDP (int) 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 (int) Interrupted system call. SOCKET_EBADF (int) Bad file number. SOCKET_EACCES (int) Permission denied. SOCKET_EFAULT (int) Bad address. SOCKET_EINVAL (int) Invalid argument. SOCKET_EMFILE (int) Too many open files. SOCKET_ENAMETOOLONG (int) File name too long. SOCKET_ENOTEMPTY (int) Directory not empty. SOCKET_ELOOP (int) Too many symbolic links encountered. SOCKET_EWOULDBLOCK (int) Operation would block. SOCKET_EREMOTE (int) Object is remote. SOCKET_EUSERS (int) Too many users. SOCKET_ENOTSOCK (int) Socket operation on non-socket. SOCKET_EDESTADDRREQ (int) Destination address required. SOCKET_EMSGSIZE (int) Message too long. SOCKET_EPROTOTYPE (int) Protocol wrong type for socket. SOCKET_EPROTONOSUPPORT (int) Protocol not supported. SOCKET_ESOCKTNOSUPPORT (int) Socket type not supported. SOCKET_EOPNOTSUPP (int) Operation not supported on transport endpoint. SOCKET_EPFNOSUPPORT (int) Protocol family not supported. SOCKET_EAFNOSUPPORT (int) Address family not supported by protocol. SOCKET_EADDRNOTAVAIL (int) Cannot assign requested address. SOCKET_ENETDOWN (int) Network is down. SOCKET_ENETUNREACH (int) Network is unreachable. SOCKET_ENETRESET (int) Network dropped connection because of reset. SOCKET_ECONNABORTED (int) Software caused connection abort. SOCKET_ECONNRESET (int) Connection reset by peer. SOCKET_ENOBUFS (int) No buffer space available. SOCKET_EISCONN (int) Transport endpoint is already connected. SOCKET_ENOTCONN (int) Transport endpoint is not connected. SOCKET_ESHUTDOWN (int) Cannot send after transport endpoint shutdown. SOCKET_ETIMEDOUT (int) Connection timed out. SOCKET_ECONNREFUSED (int) Connection refused. SOCKET_EHOSTDOWN (int) Host is down. SOCKET_EHOSTUNREACH (int) No route to host. SOCKET_EALREADY (int) Operation already in progress. SOCKET_EINPROGRESS (int) Operation now in progress. The following constants are only defined under Windows. SOCKET_ENOPROTOOPT (int) SOCKET_EADDRINUSE (int) SOCKET_ETOOMYREFS (int) SOCKET_EPROCLIM (int) SOCKET_EDUOT (int) SOCKET_ESTALE (int) SOCKET_EDISCON (int) SOCKET_SYSNOTREADY (int) SOCKET_VERNOTSUPPORTED (int) SOCKET_NOTINITIALISED (int) SOCKET_HOST_NOT_FOUND (int) SOCKET_TRY_AGAIN (int) SOCKET_NO_RECOVERY (int) SOCKET_NO_DATA (int) SOCKET_NO_ADDRESS (int) 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 (int) Operation not permitted. SOCKET_ENOENT (int) No such file or directory. SOCKET_EIO (int) I/O error. SOCKET_ENXIO (int) No such device or address. SOCKET_E2BIG (int) Arg list too long. SOCKET_EAGAIN (int) Try again. SOCKET_ENOMEM (int) Out of memory. SOCKET_ENOTBLK (int) Block device required. SOCKET_EBUSY (int) Device or resource busy. SOCKET_EEXIST (int) File exists. SOCKET_EXDEV (int) Cross-device link. SOCKET_ENODEV (int) No such device. SOCKET_ENOTDIR (int) Not a directory. SOCKET_EISDIR (int) Is a directory. SOCKET_ENFILE (int) File table overflow. SOCKET_ENOTTY (int) Not a typewriter. SOCKET_ENOSPC (int) No space left on device. SOCKET_ESPIPE (int) Illegal seek. SOCKET_EROFS (int) Read-only file system. SOCKET_EMLINK (int) Too many links. SOCKET_EPIPE (int) Broken pipe. SOCKET_ENOLCK (int) No record locks available. SOCKET_ENOSYS (int) Function not implemented. SOCKET_ENOMSG (int) No message of desired type. SOCKET_EIDRM (int) Identifier removed. SOCKET_ECHRNG (int) Channel number out of range. SOCKET_EL2NSYNC (int) Level 2 not synchronized. SOCKET_EL3HLT (int) Level 3 halted. SOCKET_EL3RST (int) Level 3 reset. SOCKET_ELNRNG (int) Link number out of range. SOCKET_EUNATCH (int) Protocol driver not attached. SOCKET_ENOCSI (int) No CSI structure available. SOCKET_EL2HLT (int) Level 2 halted. SOCKET_EBADE (int) Invalid exchange. SOCKET_EBADR (int) Invalid request descriptor. SOCKET_EXFULL (int) Exchange full. SOCKET_ENOANO (int) No anode. SOCKET_EBADRQC (int) Invalid request code. SOCKET_EBADSLT (int) Invalid slot. SOCKET_ENOSTR (int) Device not a stream. SOCKET_ENODATA (int) No data available. SOCKET_ETIME (int) Timer expired. SOCKET_ENOSR (int) Out of streams resources. SOCKET_ENONET (int) Machine is not on the network. SOCKET_ENOLINK (int) Link has been severed. SOCKET_EADV (int) Advertise error. SOCKET_ESRMNT (int) Srmount error. SOCKET_ECOMM (int) Communication error on send. SOCKET_EPROTO (int) Protocol error. SOCKET_EMULTIHOP (int) Multihop attempted. SOCKET_EBADMSG (int) Not a data message. SOCKET_ENOTUNIQ (int) Name not unique on network. SOCKET_EBADFD (int) File descriptor in bad state. SOCKET_EREMCHG (int) Remote address changed. SOCKET_ERESTART (int) Interrupted system call should be restarted. SOCKET_ESTRPIPE (int) Streams pipe error. SOCKET_EPROTOOPT (int) Protocol not available. SOCKET_ADDRINUSE (int) Address already in use. SOCKET_ETOOMANYREFS (int) Too many references: cannot splice. SOCKET_EISNAM (int) Is a named type file. SOCKET_EREMOTEIO (int) Remote I/O error. SOCKET_EDQUOT (int) Quota exceeded. SOCKET_ENOMEDIUM (int) No medium found. SOCKET_EMEDIUMTYPE (int) Wrong medium type. SCM_RIGHTS (int) Send or receive a set of open file descriptors from another process. SCM_CREDENTIALS (int)