.TH GETSOCKOPT 2
.SH NAME
getsockopt \- get the value of a socket option.
.SH SYNOPSIS
.ft B
#include <sys/socket.h>

.in +5
.ti -5
int getsockopt(int \fIsd\fP, int \fIlevel\fP, int \fIopt_name\fP, void * \fIopt_val\fP, socklen_t * \fIopt_len\fP);
.br
.ft P
.SH DESCRIPTION
getsockopt() provides an interface to get the value of a specific 
option, referenced by \fIopt_name\fP, for a given socket descriptor 
\fIsd\fP.
.SH RETURN VALUES
On success, this function returns 0. On error, -1 is returned and
\fIerrno\fP is set.
.SH ERRORS
.TP 15
[ENOSYS]
The option \fIopt_name\fP is not available/supported at the \fIlevel\fP 
specified for the socket \fIsd\fP.
.TP 15
[ENOTSOCK]
\fIsd\fP is not a socket descriptor.
.SH SEE ALSO
.BR socket(2),
.BR socketpair(2),
.BR setsockopt(2)