= DNS =

dig martin.wuertele.net any
dig orata.debian.or.at any
dig debian.or.at any

tcp over dns: nsdx


= URL =

Identification of Resources

http://hans:geheim@www.example.org:80/demo/example.cgi?land=de&stadt=aa#abschnitt1


URI: allgemeiner (Schema:schemaspezifischer Teil)
Schemata: xmpp, pop, telnet, mailto
Innoffiziell: zeroconf, fish, svn, tar

IRI: Erweiterung zu Unicode
"Punycode"

RFC 2396


= HTTP =

zustandsloses Protokoll für beliebige Daten
Request/Response
Header + Body

echo "GET / HTTP/1.1\nHost: www.w3.org\n" | nc -vv www.w3.org 80
sudo tcpdump -A port 80

Proxies, Caches machen es sehr flexibel

RFC 2068 / 2616


= MIME =

sowohl auf HTML Ebene: a(type), form(accept, enctype), input(accept), link(type), script(type), style(type),..
als auf HTTP Ebene: POST Request Content-Type: application/x-www-form-urlencoded, GET, POST,.. Response
http://de.selfhtml.org/diverses/mimetypen.htm

in Kategorien augeteilt: text, image, video, audio, application

multipart bei HTTP eher weniger verwendet da HTTP 1.1 mehrere Abfragen pro Session imho das Problem besser löst


= LINKS =

Html .. sehr gut von Menschen für Menschen

Atom, RSS .. Newsletters/Update, Format for Computer, Content for Human

XML .. Format & Content for Computer, but readable

JSON .. like XML but more compact syntax at cost of some features (namespaces, URI)


= REST =

REpresentational State Transfer

-> Architektur Stil

Putting it all together...

Verb         Safe Idempotent   Description
HTTP GET     Yes  Yes          GET a resource identified by an URL
HTTP PUT     No   Yes          CREATE or UPDATE a resource identified by a client-specified URL
HTTP POST    No   No           APPEND to a resource identified by a URL
HTTP DELETE  No   Yes          DELETE a resource identified by a URL