freebsd-skq/lib/libc/sys/getsockname.2

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.\"     @(#)getsockname.2	8.1 (Berkeley) 6/4/93
.\"
.Dd June 4, 1993
.Dt GETSOCKNAME 2
.Os BSD 4.2
.Sh NAME
.Nm getsockname
.Nd get socket name
.Sh SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <sys/socket.h>
.Ft int
.Fn getsockname "int s" "struct sockaddr *name" "int *namelen"
.Sh DESCRIPTION
.Fn Getsockname
returns the current 
.Fa name
for the specified socket.  The
.Fa namelen
parameter should be initialized to indicate
the amount of space pointed to by
.Fa name .
On return it contains the actual size of the name
returned (in bytes).
.Sh IMPLEMENTATION NOTES
.Pp
In the non-threaded library
.Fn getsockname
is implemented as the
.Va getsockname
syscall.
.Pp
In the threaded library, the
.Va getsockname
syscall is assembled to
.Fn _thread_sys_getsockname
and
.Fn getsockname
is implemented as a function which locks
.Va fd
for read and write, then calls
.Fn _thread_sys_getsockname .
Before returning,
.Fn getsockname
unlocks
.Va fd .
.Sh RETURN VALUES
A 0 is returned if the call succeeds, -1 if it fails.
.Sh ERRORS
The call succeeds unless:
.Bl -tag -width ENOTSOCKAA
.It Bq Er EBADF
The argument
.Fa s
is not a valid descriptor.
.It Bq Er ENOTSOCK
The argument
.Fa s
is a file, not a socket.
.It Bq Er ENOBUFS
Insufficient resources were available in the system
to perform the operation.
.It Bq Er EFAULT
The 
.Fa name
parameter points to memory not in a valid part of the
process address space.
.El
.Sh SEE ALSO
.Xr bind 2 ,
.Xr getpeername 2 ,
.Xr socket 2
.Sh BUGS
Names bound to sockets in the UNIX domain are inaccessible;
.Xr getsockname
returns a zero length name.
.Sh HISTORY
The
.Fn getsockname
function call appeared in
.Bx 4.2 .