Current File : //opt/alt/ruby18/share/ri/1.8/system/BasicSocket/setsockopt-i.yaml
--- !ruby/object:RI::MethodDescription
aliases: []
block_params:
comment:
- !ruby/struct:SM::Flow::P
body: Sets a socket option. These are protocol and system specific, see your local sytem documentation for details.
- !ruby/struct:SM::Flow::H
level: 3
text: Parameters
- !ruby/object:SM::Flow::LIST
contents:
- !ruby/struct:SM::Flow::LI
label: "*"
body: <tt>level</tt> is an integer, usually one of the SOL_ constants such as Socket::SOL_SOCKET, or a protocol level.
- !ruby/struct:SM::Flow::LI
label: "*"
body: <tt>optname</tt> is an integer, usually one of the SO_ constants, such as Socket::SO_REUSEADDR.
- !ruby/struct:SM::Flow::LI
label: "*"
body: "<tt>optval</tt> is the value of the option, it is passed to the underlying setsockopt() as a pointer to a certain number of bytes. How this is done depends on the type:"
- !ruby/object:SM::Flow::LIST
contents:
- !ruby/struct:SM::Flow::LI
label: "-"
body: "Fixnum: value is assigned to an int, and a pointer to the int is passed, with length of sizeof(int)."
- !ruby/struct:SM::Flow::LI
label: "-"
body: "true or false: 1 or 0 (respectively) is assigned to an int, and the int is passed as for a Fixnum. Note that <tt>false</tt> must be passed, not <tt>nil</tt>."
- !ruby/struct:SM::Flow::LI
label: "-"
body: "String: the string's data and length is passed to the socket."
type: :BULLET
type: :BULLET
- !ruby/struct:SM::Flow::H
level: 3
text: Examples
- !ruby/struct:SM::Flow::P
body: "Some socket options are integers with boolean values, in this case #setsockopt could be called like this:"
- !ruby/struct:SM::Flow::VERB
body: " sock.setsockopt(Socket::SOL_SOCKET,Socket::SO_REUSEADDR, true)\n"
- !ruby/struct:SM::Flow::P
body: "Some socket options are integers with numeric values, in this case #setsockopt could be called like this:"
- !ruby/struct:SM::Flow::VERB
body: " sock.setsockopt(Socket::IPPROTO_IP, Socket::IP_TTL, 255)\n"
- !ruby/struct:SM::Flow::P
body: "Option values may be structs. Passing them can be complex as it involves examining your system headers to determine the correct definition. An example is an <tt>ip_mreq</tt>, which may be defined in your system headers as:"
- !ruby/struct:SM::Flow::VERB
body: " struct ip_mreq {\n struct in_addr imr_multiaddr;\n struct in_addr imr_interface;\n };\n"
- !ruby/struct:SM::Flow::P
body: "In this case #setsockopt could be called like this:"
- !ruby/struct:SM::Flow::VERB
body: " optval = IPAddr.new("224.0.0.251") + Socket::INADDR_ANY\n sock.setsockopt(Socket::IPPROTO_IP, Socket::IP_ADD_MEMBERSHIP, optval)\n"
full_name: BasicSocket#setsockopt
is_singleton: false
name: setsockopt
params: " setsockopt(level, optname, optval)\n"
visibility: public