bind(2) bind(2) NAME bind - bind an address to a socket SYNOPSIS #include <sys/socket.h> AF_CCITT only #include <x25/x25addrstr.h> AF_INET only #include <netinet/in.h> AF_UNIX only #include <sys/un.h> int bind(int s, const void *addr, int addrlen); _XOPEN_SOURCE_EXTENDED only int bind(int s, const struct sockaddr *addr, size_t addrlen); DESCRIPTION The bind() system call assigns an address to an unbound socket. When a socket is created with socket(), it exists in an address space (address family) but has no address assigned. bind() causes the socket whose descriptor is s to become bound to the address specified in the socket address structure pointed to by addr. addrlen must specify the size of the address structure. Since the size of the socket address structure varies between socket address families, the correct socket address structure should be used with each address family (for example, struct sockaddr_in for AF_INET, and struct sockaddr_un for AF_UNIX). Typically, the sizeof() function is used to pass this value in the bind() call (for example, sizeof(struct sockaddr_in)). The rules used in address binding vary between communication domains. For example, when binding an AF_UNIX socket to a path name (such as /tmp/mysocket), an open file having that name is created in the file system. When the bound socket is closed, that file still exists unless it is removed or unlinked. When binding an AF_INET socket, sin_port can be a port number or it can be zero. If sin_port is zero, the system assigns an unused port number automatically. RETURN VALUE bind() returns the following values: 0 Successful completion. -1 Failure. errno is set to indicate the error. ERRORS If bind() fails, errno is set to one of the following values. [EACCES] The requested address is protected, and the current user has inadequate permission to access it. (This error can be returned by AF_INET only.) [EADDRINUSE] The specified address is already in use. [EADDRNOTAVAIL] The specified address is invalid or not available from the local machine, or for AF_CCITT sockets which use "wild card" addressing, the specified address space overlays the address space of an existing bind. [EAFNOSUPPORT] The specified address is not a valid address for the address family of this socket. [EBADF] s is not a valid file descriptor. [EDESTADDRREQ] No addr parameter was specified. [EFAULT] addr is not a valid pointer. [EINVAL] The socket is already bound to an address, the socket has been shut down, addrlen is a bad value, or an attempt was made to bind() an AF_UNIX socket to an NFS-mounted (remote) name. AF_CCITT: The protocol-ID length is negative or greater than 8, the X.121 address string contains an illegal character, or the X.121 address string is greater than 15 digits long. [ENETDOWN] The x25ifname field name specifies an interface that was shut down, or never initialized, or whose Level 2 protocol indicates that the link is not working: Wires might be broken, the interface hoods on the modem are broken, the modem failed, the phone connection failed (this error can be returned by AF_CCITT only), noise interfered with the line for a long period of time. [ENETUNREACH] The X.25 Level 2 protocol is down. The X.25 link is not working: Wires might be broken, or connections are loose on the interface hoods at the modem, the modem failed, or noise interfered with the line for an extremely long period of time. [ENOBUFS] No buffer space is available. The bind() cannot complete. [ENODEV] The x25ifname field name specifies a nonexistent interface. (This error can be returned by AF_CCITT only.) [ENOTSOCK] s is a valid file descriptor, but it is not a socket. [EOPNOTSUPP] The socket referenced by s does not support address binding. AUTHOR bind() was developed by the University of California, Berkeley. FUTURE DIRECTION The default behavior in this release is still the classic HP-UX BSD Sockets, however it will be changed to X/Open Sockets in some future release. At that time, any HP-UX BSD Sockets behavior which is incompatible with X/Open Sockets may be obsoleted. HP customers are advised to migrate their applications to conform to X/Open specification( see xopen_networking(7) ). SEE ALSO connect(2), getsockname(2), listen(2), socket(2), af_ccitt(7F), inet(7F), socketx25(7), tcp(7P), udp(7P), unix(7P), xopen_networking(7). STANDARDS CONFORMANCE bind(): XPG4 Hewlett-Packard Company - 3 - HP-UX Release 10.20: July 1996