Wikipedia:Reference desk/Archives/Computing/2014 June 28

= June 28 =

SHARING HP LAPTOP AND IPADMINI
I want to share the broadband internet connection on my HP Pavilion 15 Notebook with ipad mini through WI-Fi. Ipad requesting a password. What is the default password? Is it possible to share through wi-fi? or should I install something? Please help. Thank you.175.157.91.133 (talk) 09:49, 28 June 2014 (UTC)
 * It will be the password of your PC - the one you use to login. KägeTorä - (影虎) (Chin Wag) 13:13, 28 June 2014 (UTC)

There is no password. I didn't creat any password. i just login.175.157.70.30 (talk) 00:21, 29 June 2014 (UTC)

Regards Recover my XP Machine
On the June 27, I posted a question but I perhaps did not word it correctly. I do have all updates on my XP computer up to the date when Microsoft supposedly stopped the updates. What I am asking is this: I want to recover my computer to it's original state with the operating system disc that I have but in doing that I will loose everything on my hard drive. I will back up all my files, address book, and messages etc. on an external hard drive. But my question is: How can I backup and save all the Microsoft Windows updates that I have downloaded from Microsoft up to the time when they were no longer available. I appreciate help on this topic. Thank you polkateer Polkateer (talk) 17:51, 28 June 2014 (UTC)


 * I don't think it's possible. You will have to re-download them. They are (as someone said in the previous thread) still available for download. -- BenRG (talk) 01:41, 29 June 2014 (UTC)
 * From my understanding, Microsoft will provide the existing updates for WindowsXP for the next few years, but they won't create new ones for any bugs that are found. You can download Service Pack 2 for XP from  (not sure if that's 32bit or 64bit), and SP3 for 32bit (there wasn't one for 64bit) from . You need to install atleast SP1a for SP3 to install. SP3 was released in April 2008, after installing it XP will fetch the rest of the updates required to bring your machine up to date. There was no SP4 to contain all the updates to end-of-life. CS Miller (talk) 17:32, 29 June 2014 (UTC)

What can you use to describe a string (besides regexps)
What >>>>practical<<<< options do we have, when we want to describe a string but don't want to use regexp (because they are too weak to express information like emails, html and the like). How could you perform a search of the kind: sometoolbetterthangrep somepatterninaformbetterthanaregex filenames


 * The general topic of taking a string of symbols and extracting from it information based on lexical and syntactic rules is parsing. The "parser development software" section of that article, and the comparison of parser generators article, lists practical software that can help. -- Finlay McWalterᚠTalk 19:51, 28 June 2014 (UTC)


 * The language of regexps is a regular language and they are implemented using finite state automata. The next step up from regular languages and FSAs in terms of expressiveness and "computing power" are context-free grammars that can be parsed by pushdown automata with a stack (also see the template at the bottom of that page lists many more types of grammar and the corresponding machine that recognizes them). There are also PEGs, but I can't say anything on them. As to processing HTML, a cleaner way to search it is to parse it and traverse the resulting tree, rather than anything involving regexps and treating it as though it were a stream of bytes. And you'd have to specify the search pattern, if there was such a grep-like command line tool, in something much like XPath Asmrulz (talk) 20:27, 28 June 2014 (UTC)


 * As the context-free grammar article indicates, an important practical notation for describing a grammar is Backus–Naur Form (also called Backus Normal Form or BNF), now often written in slightly altered forms. There is also the van Wijngaarden grammar notation. --70.49.171.225 (talk) 05:21, 29 June 2014 (UTC)


 * There really aren't any >>>>>practical<<<<< options. There are tools for recognizing arbitrarily complicated things, but to be practically useful they would have to be integrated with a search engine, and that isn't something that an unsophisticated end-user could do. Looie496 (talk) 15:00, 29 June 2014 (UTC)
 * I shouldn't have placed so much enphasis on the 'practical', but I was thinking about something not much more complicated than a regex. The examples in the Backus Normal Form article, however, don't look amazingly complicated, although they are not something that you type in a search box, but it could still be incorporated in a script with some thinking. But yes, this is not something that an end-user would do when he only expects to push buttons in a GUI.. Abaget (talk) 15:32, 29 June 2014 (UTC)


 * Perl/PCRE "regexes", despite the name, can match arbitrary context-free languages, and many tools have PCRE built in. For example, grep -P "^((\((?1)\))*)$" will match lines consisting of balanced parentheses (if you're using GNU grep). The syntax is horrible, but maybe this is what you're looking for. -- BenRG (talk) 16:10, 29 June 2014 (UTC)