1BIND(3P) POSIX Programmer's Manual BIND(3P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
13 bind — bind a name to a socket
14
16 #include <sys/socket.h>
17 int bind(int socket, const struct sockaddr *address,
19 socklen_t address_len);
20
22 The bind() function shall assign a local socket address address to a
23 socket identified by descriptor socket that has no local socket address
24 assigned. Sockets created with the socket() function are initially
25 unnamed; they are identified only by their address family.
26 The bind() function takes the following arguments:
28 socket Specifies the file descriptor of the socket to be bound.
30 address Points to a sockaddr structure containing the address to be
32 bound to the socket. The length and format of the address
33 depend on the address family of the socket.
34 address_len Specifies the length of the sockaddr structure pointed to
36 by the address argument.
37 The socket specified by socket may require the process to have appro‐
39 priate privileges to use the bind() function.
40 If the address family of the socket is AF_UNIX and the pathname in
42 address names a symbolic link, bind() shall fail and set errno to [EAD‐
43 DRINUSE].
44 If the socket address cannot be assigned immediately and O_NONBLOCK is
46 set for the file descriptor for the socket, bind() shall fail and set
47 errno to [EINPROGRESS], but the assignment request shall not be
48 aborted, and the assignment shall be completed asynchronously. Subse‐
49 quent calls to bind() for the same socket, before the assignment is
50 completed, shall fail and set errno to [EALREADY].
51 When the assignment has been performed asynchronously, pselect(),
53 select(), and poll() shall indicate that the file descriptor for the
54 socket is ready for reading and writing.
55
57 Upon successful completion, bind() shall return 0; otherwise, −1 shall
58 be returned and errno set to indicate the error.
59
61 The bind() function shall fail if:
62 EADDRINUSE
64 The specified address is already in use.
65 EADDRNOTAVAIL
67 The specified address is not available from the local machine.
68 EAFNOSUPPORT
70 The specified address is not a valid address for the address
71 family of the specified socket.
72 EALREADY
74 An assignment request is already in progress for the specified
75 socket.
76 EBADF The socket argument is not a valid file descriptor.
78 EINPROGRESS
80 O_NONBLOCK is set for the file descriptor for the socket and the
81 assignment cannot be immediately performed; the assignment shall
82 be performed asynchronously.
83 EINVAL The socket is already bound to an address, and the protocol does
85 not support binding to a new address; or the socket has been
86 shut down.
87 ENOBUFS
89 Insufficient resources were available to complete the call.
90 ENOTSOCK
92 The socket argument does not refer to a socket.
93 EOPNOTSUPP
95 The socket type of the specified socket does not support binding
96 to an address.
97 If the address family of the socket is AF_UNIX, then bind() shall fail
99 if:
100 EACCES A component of the path prefix denies search permission, or the
102 requested name requires writing in a directory with a mode that
103 denies write permission.
104 EDESTADDRREQ or EISDIR
106 The address argument is a null pointer.
107 EIO An I/O error occurred.
109 ELOOP A loop exists in symbolic links encountered during resolution of
111 the pathname in address.
112 ENAMETOOLONG
114 The length of a component of a pathname is longer than
115 {NAME_MAX}.
116 ENOENT A component of the path prefix of the pathname in address does
118 not name an existing file or the pathname is an empty string.
119 ENOENT or ENOTDIR
121 The pathname in address contains at least one non-<slash> char‐
122 acter and ends with one or more trailing <slash> characters. If
123 the pathname names an existing file, an [ENOENT] error shall not
124 occur.
125 ENOTDIR
127 A component of the path prefix of the pathname in address names
128 an existing file that is neither a directory nor a symbolic link
129 to a directory, or the pathname in address contains at least one
130 non-<slash> character and ends with one or more trailing <slash>
131 characters and the last pathname component names an existing
132 file that is neither a directory nor a symbolic link to a direc‐
133 tory.
134 EROFS The name would reside on a read-only file system.
136 The bind() function may fail if:
138 EACCES The specified address is protected and the current user does not
140 have permission to bind to it.
141 EINVAL The address_len argument is not a valid length for the address
143 family.
144 EISCONN
146 The socket is already connected.
147 ELOOP More than {SYMLOOP_MAX} symbolic links were encountered during
149 resolution of the pathname in address.
150 ENAMETOOLONG
152 The length of a pathname exceeds {PATH_MAX}, or pathname resolu‐
153 tion of a symbolic link produced an intermediate result with a
154 length that exceeds {PATH_MAX}.
155 The following sections are informative.
157
159 The following code segment shows how to create a socket and bind it to
160 a name in the AF_UNIX domain.
161 #define MY_SOCK_PATH "/somepath"
163 int sfd;
165 struct sockaddr_un my_addr;
166 sfd = socket(AF_UNIX, SOCK_STREAM, 0);
168 if (sfd == −1)
169 /* Handle error */;
170 memset(&my_addr, '\0', sizeof(struct sockaddr_un));
172 /* Clear structure */
173 my_addr.sun_family = AF_UNIX;
174 strncpy(my_addr.sun_path, MY_SOCK_PATH, sizeof(my_addr.sun_path) −1);
175 if (bind(sfd, (struct sockaddr *) &my_addr,
177 sizeof(struct sockaddr_un)) == −1)
178 /* Handle error */;
179
181 An application program can retrieve the assigned socket name with the
182 getsockname() function.
183
185 None.
186
188 None.
189
191 connect(), getsockname(), listen(), socket()
192 The Base Definitions volume of POSIX.1‐2008, <sys_socket.h>
194
196 Portions of this text are reprinted and reproduced in electronic form
197 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
198 -- Portable Operating System Interface (POSIX), The Open Group Base
199 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
200 cal and Electronics Engineers, Inc and The Open Group. (This is
201 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
202 event of any discrepancy between this version and the original IEEE and
203 The Open Group Standard, the original IEEE and The Open Group Standard
204 is the referee document. The original Standard can be obtained online
205 at http://www.unix.org/online.html .
206 Any typographical or formatting errors that appear in this page are
208 most likely to have been introduced during the conversion of the source
209 files to man page format. To report such errors, see https://www.ker‐
210 nel.org/doc/man-pages/reporting_bugs.html .
211IEEE/The Open Group 2013 BIND(3P)