Scroll to navigation

BINDAT(2) System Calls Manual BINDAT(2)


bindatassign a local protocol address to a socket


Standard C Library (libc, -lc)


#include <sys/types.h>
#include <sys/socket.h>

#include <fcntl.h>

bindat(int fd, int s, const struct sockaddr *addr, socklen_t addrlen);


The () system call assigns the local protocol address to a socket. When passed the special value AT_FDCWD in the fd parameter, the behavior is identical to a call to bind(2). Otherwise, bindat() works like the bind(2) system call with two exceptions:

  1. It is limited to sockets in the PF_LOCAL domain.

  2. If the file path stored in the sun_path field of the sockaddr_un structure is a relative path, it is located relative to the directory associated with the file descriptor fd.


The bindat() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.


The bindat() system call may fail with the same errors as the bind(2) system call or with the following errors:

The sun_path field does not specify an absolute path and the fd argument is neither AT_FDCWD nor a valid file descriptor.
The sun_path field is not an absolute path and fd is neither AT_FDCWD nor a file descriptor associated with a directory.


bind(2), connectat(2), socket(2), unix(4)


The bindat was developed by Pawel Jakub Dawidek <> under sponsorship from the FreeBSD Foundation.

February 13, 2013 Debian