TechCrunch Sculpting text with regex, grep, sed and awk Theory: Regular languages Many tools for searching and sculpting text rely on a pattern language known as regular expressions. The theory of regular languages underpins regular expressions. (Caveat: Some modern "regular" expression systems can describe irregular languages, which is why the term "regex" is preferred for these systems.) Regular languages are a class of formal language equivalent in power to those recognized by deterministic finite automata (DFAs) and nondeterministic finite automata (NFAs). [See my post on converting regular expressions to NFAs.] In formal language theory, a language is a set of strings. For example, {"foo"} and {"foo", "foobar"} are formal (if small) languages. (Mathematicians don't typically put quotes around a string, preferring to let the fixed-width typewriter font distinguish it as one, but I'm guessing that programmers are more comfortable with the quotes around strings.) In regular language theory, there are two atomic languages: Useful grep flags The +? #!
Network-Tools | Traceroute, Ping, Domain Name Server (DNS) Lookup, WHOIS Reverse IP Lookup - Find Other Web Sites Hosted on a Web Server Find other sites hosted on a web server by entering a domain or IP address above. Note: For those of you interested, as of May 2014, my database has grown to over 100 million domain names. I am now offering this domain list for purchase. A reverse IP domain check takes a domain name or IP address pointing to a web server and searches for other sites known to be hosted on that same web server. Data is gathered from search engine results, which are not guaranteed to be complete. Background All web sites are hosted on web servers, which are computers running specialized software that distribute web content as requested. As of 2003, more than 87% of all active domains names were found to share their IP addresses (i.e. their web servers) with one or more additional domains. While IP sharing is typically transparent to ordinary users, it may cause complications for both search engine optimization and web site filtering. Concerning SEO (search engine optimization) Concerning web site filtering
InternetSupervision | Website Monitoring Services Traditional DNS Howto Traditional DNS Howto Version 1.0 Authors: Tom Adelstein <tom [dot] adelstein [at] gmail [dot] com> Falko Timme <ft [at] falkotimme [dot] com> Last edited: 03/11/2006 Linux system administrators should learn traditional DNS. Front-ends and quick templates to setup domain records have a place in managing sites. When confronted with DNS configurations already in existence, nothing can substitute for knowing and using the fundamentals. The vast majority of users on the Internet have no clue about DNS. The Internet uses TCP/IP protocol to send and receive everything on the Internet. You see Google.com is an name in a database that your browser consults to find the IP address of the Google web site. If you're sitting there reading this and going, "Oh yeah, I already know about that", then hold on a minute or two. The Domain Name System of the Internet makes up the largest distributed database on the planet and it's quite ingenious. Linux uses BIND to perform DNS functions.
Настройка VPN сервера на Cisco (PPTP с шифрованием) | Wisedec.ru Самым простым сервером VPN настраиваемым на маршрутизаторах Cisco является сервер PPTP: Для настройки PPTP сервера необходимо задать на маршрутизаторе всего несколько команд. Ниже приведен перечень всех команд, которые нужно ввести (просто скопируйте этот в текстовый редактор, подправьте IP адреса и CTRL-C, CTRL-V в режиме конфигурирования) username vpnuser password 123456ip local pool test 192.168.1.1 192.168.1.250 vpdn enable vpdn-group 1 accept-dialin protocol pptp virtual-template 1 exit interface virtual-template 1 encapsulation ppp peer default ip address pool test ip unnumbered FastEthernet0/0 ppp encrypt mppe auto ppp authentication pap chap ms-chap Подробности: Клиентская часть VPN есть на любом компьютере с Windows – это стандартное удаленное соединение. PPTP можно настроить на любом маршрутизаторе, но не в любой IOS. 2621#configure terminal Enter configuration commands, one per line. 2621(config)#vpdn enable (Если маршрутизатор не выругался, значит нам повезло. ! ! ! Все.