rebol [ File: %dns-async-example.r Title: "Example for async dns:// and spam dns server" Author: "Romano Paolo Tenca" Date: 04/10/03 Purpose: { Example code to: 1) use the dns:// protocol in async mode 2) use the dns:// protocol to check spam address in async mode } Note: { This program requires View (1.2.1 or later) to visualize results (and test async behaviour), but the async code itself should work also under Core. Change the View code with some prints to test it under Core. } library: [ level: 'intermediate platform: 'all type: [tutorial] domain: [internet email] tested-under: support: license: see-also: none ] ] ;----------- Support functions ---------- wait-find: func [ "Find a port in the system wait list" port [port!] ][find system/ports/wait-list port] wait-stop: func [ "Remove a port from the system wait list" port [port!] ][remove wait-find port] wait-start: func [ "Insert a port in the system wait list" port [port!] ][any [wait-find port insert tail system/ports/wait-list port]] ;----------- dns-spam-ctx ---------- dns-spam-ctx: context [ host-list: reduce [ ;dns address dns check for spam "relays.visi.com" 127.0.0.2 "list.dsbl.org" 127.0.0.2 "bl.spamcop.net" 127.0.0.2 ;"dsn.rfc-ignorant.org" 127.0.0.2 ;"sbl.spamhaus.org" 127.0.0.2 ] ask-address: func [ "Ask an address conversion to an dns:///async port" port [port!] ][ ;visualize a message if value? 'f-a [ insert tail f-a/text reform ["Asking" first port/user-data/read-list "to" port/user-data/host newline] f-a/line-list: none show f-a ] ;inserting an address in a dns:// async port starts the conversion ;when the result will be ready, the port/awake function will be called insert port rejoin [reverse first port/user-data/read-list "." port/user-data/host] ] next-item: func [ "Get the next address to test" port [port!] result [logic!] /local tmp user-data ][ user-data: port/user-data ;next address to test user-data/read-list: skip user-data/read-list 2 ;at the end? -> stop either tail? user-data/read-list [ wait-stop port ;remove the port from the system wait list close port ][ ask-address port ;ask for a new address ] ] ;The awake function of he dns:// port spam-awake: func [port /local result][ ;read the result from itself and check it result: port/user-data/check = copy port ;remember the result ('or is used to not overwrite the results of others ports) port/user-data/read-list/2: port/user-data/read-list/2 or result ;if match the required value, print a message if result [ ;visualize something insert tail f-a2/text reform [ first port/user-data/read-list "is spam for" port/user-data/host newline ] f-a2/line-list: none show f-a2 ] next-item port result ;start to check the next address false ;= continue to wait ] set 'start-spam func [ "Open and initialize a dns:///async port for every host" read-list [block!] /local port ][ foreach [hst check] host-list [ port: open/no-wait make port! [ scheme: 'dns host: "/async" user-data: reduce ['host hst 'check check 'read-list read-list] awake: :spam-awake ] wait-start port ;insert the port in the system wait-list (for wait []) ask-address port ;ask the first address ] ] ] ;example ;IP to check test-list: reduce [ 192.168.1.35 false 217.128.120.69 false 213.36.114.1 false 217.132.9.69 false 210.49.39.53 false 29.182.79.223 false 213.41.147.86 false 193.70.192.59 false 65.35.3.133 false 170.139.28.247 false 193.70.192.90 false 211.28.63.207 false 193.70.192.55 false 210.101.90.44 false 193.70.192.55 false 68.102.53.146 false 167.16.235.87 false 211.28.63.207 false 193.70.192.90 false 62.183.152.122 false 61.143.117.79 false ] start-spam test-list ;initialize all view layout [ across f-a: area 300x400 para [] f-a2: area 300x400 para [] return button "quit" [quit] ]