GETSOCKOPT(2)           COMMAND REFERENCE           GETSOCKOPT(2)



NAME
     getsockopt, setsockopt - get and set options on sockets

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

     getsockopt(s, level, optname, optval, optlen)
     int s, level, optname;
     char *optval;
     int *optlen;

     setsockopt(s, level, optname, optval, optlen)
     int s, level, optname;
     char *optval;
     int optlen;

DESCRIPTION
     Getsockopt and setsockopt manipulate options associated with
     a socket.

     To manipulate options at the ``socket'' level, level is
     specified as SOL_SOCKET.

     The parameters optval and optlen are used to specify option
     values for setsockopt.  For getsockopt they identify a
     buffer in which the value for the requested option is to be
     returned.  For getsockopt, optlen is a value-result
     parameter initially containing the size of the buffer
     pointed to by optval.  It is modified on return to indicate
     the actual size of the value returned.  If no option value
     is to be supplied or returned, optval may be supplied as 0.

     Optname and any specified option value are passed
     uninterpreted to the appropriate protocol module for
     interpretation.  The include file <sys/socket.h> contains
     definitions for ``socket'' level options; see socket(2).  At
     this level, optname is a single option; that is, only one
     option can be specified per call to getsockopt or
     setsockopt.  Also, setsockopt will fail if an optval of size
     greater than the mbuf data length (defined in <sys/mbuf.h>)
     is specified.

DIAGNOSTICS
     The call succeeds unless:

     [EBADF]      The argument s is not a valid descriptor.

     [ENOTSOCK]   The argument s is a file, not a socket.

     [ENOPROTOOPT]
                  The option specified in getsockopt is not set.



Printed 5/12/88                                                 1

GETSOCKOPT(2)           COMMAND REFERENCE           GETSOCKOPT(2)



     [EINVAL]     Optname or level is unknown; size of optval is
                  too large (setsockopt).

     [EFAULT]     The options are not in a valid part of the
                  process address space.

     [ENOBUFS]    No system buffer space is available.

RETURN VALUE
     [0]  Successful call. In the case of getsockopt, the option
          specified by optname is set.

     [-1] Unsuccessful call or optname is not set. An error code
          is stored into the global variable errno.

CAVEATS
     At present, only ``socket'' level options are allowed.  Of
     these, only SO_LINGER accepts an optval argument of integer
     size to setsockopt.

     There is no provision for resetting an option, once set.

SEE ALSO
     socket(2) and getprotoent(3n).































Printed 5/12/88                                                 2

%%index%%
na:384,107;
sy:491,2460;
de:2951,2280;
di:5231,462;6149,403;
rv:6552,484;
ca:7036,408;
se:7444,183;
%%index%%000000000133