GETPEERNAME(2) Linux Programmer s Manual GETPEERNAME(2)

NAME getpeername - get name of connected peer socket

SYNOPSIS #include <sys/socket.h>

int getpeername(int sockfd, struct sockaddr *addr, socklen_t *addrlen);

DESCRIPTION getpeername() returns the address of the peer connected to the socket sockfd, in the buffer pointed to by addr. The addrlen argument should be initialized to indicate the amount of space pointed to by addr. On return it contains the actual size of the name returned (in bytes). The name is truncated if the buffer provided is too small.

The returned address is truncated if the buffer provided is too small; in this case, addrlen will return a value greater than was supplied to the call.

RETURN VALUE On success, zero is returned. On error, -1 is returned, and errno is set appropriately.

ERRORS EBADF The argument sockfd is not a valid descriptor.

EFAULT The addr argument points to memory not in a valid part of the process address space.

EINVAL addrlen is invalid (e.g., is negative).

ENOBUFS Insufficient resources were available in the system to perform the operation.

ENOTCONN The socket is not connected.

ENOTSOCK The argument sockfd is a file, not a socket.

CONFORMING TO SVr4, 4.4BSD (the getpeername() function call first appeared in 4.2BSD), POSIX.1-2001.

NOTES The third argument of getpeername() is in reality an int * (and this is what 4.x BSD and libc4 and libc5 have). Some POSIX confusion resulted in the present socklen_t, also used by glibc. See also accept(2).

SEE ALSO accept(2), bind(2), getsockname(2), ip(7), socket(7), unix(7)

COLOPHON This page is part of release 3.22 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at

Linux 2008-12-03 GETPEERNAME(2)