Wikipedia:Reference desk/Archives/Computing/2011 February 4

= February 4 =

Facebook Wall
How do I show my facebook wall first instead of my info when my friends look at my page? --112.213.223.137 (talk) 03:19, 4 February 2011 (UTC)
 * As far as I know this happens by default with the recent Facebook update, so shouldn't be an issue if you've updated (which, AFAIK, has now been done automatically by FB for all users). You have to click through to get to the Info page. --jjron (talk) 13:21, 4 February 2011 (UTC)

Not having the e-mail I send wind up in other people's spam folders
I've used Yahoo Mail for nearly a decade. One of the problems lately has been e-mail I send winding up in other people's spam folders. Even an e-mail I sent to myself wound up in my own spam folder. Even e-mails from actual Yahoo employees are sometimes marked as spam in by inbox. But what I'm concerned about is not false positives from the spam filter on my own account, but rather e-mail messages I send to others being falsely labeled as spam by their e-mail programs.

I'm wondering if this would be less likely to happen if I were to use Gmail instead of Yahoo Mail. I don't know -- perhaps there's a history of spammers using Yahoo Mail accounts, and that's led to legitimate messages from yahoo.com addresses getting labeled as spam sometimes. Would my e-mail be less likely to wind up in other people's spam folders if I switch to Gmail? -- 174.116.177.235 (talk) 03:38, 4 February 2011 (UTC)


 * I have limited knowledge of what is causing your problem im afraid, i have never used yahoo. However, i can tell you as a GMail user that GMail has a wonderful spam filter. I have only once or twice ever seen spam in my inbox, and i dont recall ever seeing an important message being "false positive" and sent to spam. I would suspect GMail would serve you well, but i encourage you to see feedback from others as well. Good luck. :)


 * note: you could always give the GMail account a try, and if you dont like it delete it? :)


 * 137.81.116.186 (talk) 03:48, 4 February 2011 (UTC)


 * First, you should take a close look at the subject line of any e-mails you send. Avoid exclamation marks, quotation marks, all-capital letters, and dollar signs. Second, avoid using large fonts in the body of your message. Also avoid marketing words, like offer, join, vacation, or phrases like please read, or don't delete. Put yourself in a spammer's shoes and think about what she would put in an e-mail. Then, do the opposite. Also avoid sending e-mails to too many recipients at the same time, particularly recipients in the same domain.


 * As for switching providers, no, it won't matter. Gmail is definitely a better service than Yahoo! Mail, but mostly because it offers free POP3 access, a 25 MB attachment limit, and less-annoying ads. All e-mail providers have blacklists of spammer domains, but they couldn't possibly get away with blacklisting a major provider like Yahoo! In other words, your domain (or IP address) is either completely blocked from the system or it isn't. If it is blocked, your message will never even reach their spam folder.--Best Dog Ever (talk) 05:17, 4 February 2011 (UTC)


 * On your last point, that's not the whole story . Anti-spam filters like postini or spamassassin do a heuristics check for various criteria that may mark a message as spam. They usually won't classify something as spam just because the sender's name is "fgltzngsy" or the message is written in all caps, but if the sender's name is a random string of letters AND the message is written in all caps AND there's a dodgy link in there, the message will pass some threshold set by the administrator and will be classified as spam. It is certainly possible (and often happens) to set "is the mail sent from a domain often used by spammers?" as one of the criteria to be checked for. So getting back to the question, yes, changing your email provider may be a solution although a good portion of the spam my filters catch is sent from gmail addresses -- Ferkelparade &pi; 11:29, 4 February 2011 (UTC)


 * It's also possible that your email address has been 'hijacked' by a spammer, thus causing your address to be blacklisted. If that was the case there's probably little you can do but create a new account. --jjron (talk) 13:24, 4 February 2011 (UTC)

my laptop doesn't like me anymore
When it is connected, it doesn't load the battery, but it only draws energy from it (not from the charger). When it is disconnected, it loads the battery. So, my only way of using it is loading the battery when it's off and then using the battery load. What's wrong? —Preceding unsigned comment added by 88.0.97.55 (talk) 10:20, 4 February 2011 (UTC)
 * I don't know what is wrong, but perhaps you could try removing the battery and connecting it to the charger; it should work off the charger power when no battery is present 82.43.92.41 (talk) 10:45, 4 February 2011 (UTC)


 * Actually not. It does not work only with the charger power. —Preceding unsigned comment added by 88.0.97.55 (talk) 10:48, 4 February 2011 (UTC)

I have similar problem, and it was because of malfunctioning power supply. (It also might be because of damaged mainboard in laptop). -Yyy (talk) 11:23, 4 February 2011 (UTC)
 * It makes sense to believe that the power supply could be the source of the problem. If the polarity is reversed (positive what should be negative, and the other way round) the loading of the battery won't be a problem, but the mainboard will not start with the wrong polarity. When you turn the laptop on, the laptop tries to work with the power supply, but it doesn't accept wrong polarity, so it switches to the battery. When it's off, the battery can load without any problem. Quest09 (talk) 16:47, 4 February 2011 (UTC)

Free HTTP proxy with full request/response logging
Once in a while I need to check the raw HTTP requests and responses exchanged by a number of programs. An HTTP proxy would be a good tool for collecting samples of message exchanges if it can record the requests and responses in full. Is there free software that will do the job? It doesn't need to do anything beyond being in the middle of a client and a server, and save the exchanges for checking. A simple and lightweight tool would be better than a powerful but complicated one. It would be ideal if the tool is available for both Windows and Linux platforms, but it would be OK if it's not. Many thanks. —Preceding unsigned comment added by 98.114.146.27 (talk) 10:37, 4 February 2011 (UTC)
 * There are lots. If you're mostly wanting to examine headers of web pages you view in browsers, use the Firebug plug-in for Firefox.  It's so awesome it's indescribable. 71.141.88.54 (talk) 12:01, 4 February 2011 (UTC)


 * Fiddler (software) is good for this sort of thing, though I think it's for Windows only. AndrewWTaylor (talk) 12:24, 4 February 2011 (UTC)


 * I agree with the above posts that you may just need a Firefox plugin. I have used Live HTTP Headers add-on to log HTTP headers.
 * If you're sure you want a full proxy server, use Squid. Squid (software) is probably the most widely-used, most versatile proxy server.  It works on almost all platforms, and can run as a local service.  It is also free software.  Squid can log anything and everything; it can also be used to inject or delete HTTP headers and other data from the communication stream for testing/debugging purposes.  Read this this Squid Cache Wiki page on logging for an overview; here are more specific technical documents on customizing the log to store whatever header information you want.  Between the Squid wiki and the Squid manual, you should find everything, but feel free to come back if you need help.  Nimur (talk) 15:38, 4 February 2011 (UTC)

Last value query
I would like some ideas for queries to solve this problem: You have two tables. Users contains a user_id field and a last_login_date field. Login contains a user_id field so you can match up all of the logins for each user. It also has a date field. The goal is to write a single query that places the last login.date into users.last_login_date per user. I feel this is a reasonable exam question, but I'm hesitant that since I already know one possible answer, I'm falsely assuming it is reasonable. -- k a i n a w &trade; 13:27, 4 February 2011 (UTC)
 * If I understand the question correctly, then  should do it.  AndrewWTaylor (talk) 14:34, 4 February 2011 (UTC)


 * Correct, but no matter how many times you explain to students that the result of a query can be used as a value for an update, they resist trying it. Further, using a reference to the outer query (users.user_id) in an inner query also meets strong resistance. So, I wonder if there are creative methods using join. I usually get  which does not work in any of the SQL engines we use. --  k a i n a w &trade; 14:44, 4 February 2011 (UTC)
 * I'm not at work so can't check it at the moment, but I think the syntax to update using a join would be something like . AndrewWTaylor (talk) 16:04, 5 February 2011 (UTC)

Mount Override
Hi,

when you create a mount or symlink in linux / unix, for example you create a symlink from /etc/blah/blahblah to /etc/passwd

so whenever you type in /etc/passwd what you really get is /etc/blah/blahblah

how does this actually get stored in the file system? How does the file system decide from giving you the absolute path (the actual /etc/passwd) and the symlink / mount you created?

Thanks! — Preceding unsigned comment added by Legolas52 (talk • contribs) 15:12, 4 February 2011 (UTC)


 * The article symbolic link describes methods of storing the link. In *nix, it is most likely stored in the inode, assuming you are using a standard *nix filesystem. -- k a i n a w &trade; 15:39, 4 February 2011 (UTC)

DVI cable for my comp monitor
I just got a new computer and I noticed that the monitor was originally using a normal VGA cord, but connected to my PC with a VGA to DVI adapter. I figured the image quality would improve if I got a DVI cable, and I'm using it now, but everything looks exactly the same. Am I missing something here? Is there something else I need to do to improve quality? I'm running at 1366x768 which seems to be the max. It won't go any higher with either the VGA or DVA cord. ScienceApe (talk) 23:09, 4 February 2011 (UTC)


 * If the quality of the VGA RAMDAC on your graphics card is good (meaning that its noise level is very low and the frequency signal generator is accurate), and if the copper cable has no significant integrity defects or serious electromagnetic interference, and if your monitor doesn't garble the analog signal as it converts it to control signals for the LCD panel, there's no reason why VGA should be poor quality. It may even be "bit-exact" with a digital representation, out to the individual RGB levels that your LCD panel can actually display.  Nimur (talk) 23:29, 4 February 2011 (UTC)