Wikipedia:Reference desk/Archives/Computing/2009 May 9

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May 9

Security: VPN versus standard database server

I'm looking at turning my home desktop computer into a private database server. My father's (Windows 2000) and my (Kubuntu 8.04) computers both have software firewalls and are also connected to the Internet (cable) through a router with a built-in firewall. Currently, neither computer can accept incoming connections, even from the other. My father wants the server to use a VPN, since the router has a special mode for VPNs; what security concerns might this eliminate, and what concerns might it create, versus simply opening the port and configuring PostgreSQL to accept logins?

If it makes any difference, I'm going to look into installing an open-source browser interface for the database if one is available, so that it can be accessed from computers without PostgreSQL client software. NeonMerlin 07:01, 9 May 2009 (UTC)

VPN may be useful for encrypting the connection, as the SQL protocol doesn't have any encryption. (There are some implementations using SSL, but they aren't common.) --grawity 18:20, 9 May 2009 (UTC)

Can't Resize Partition

Hola! I'm trying to use "GParted Live" to resize a partition on my (Windows XP) system, but I can't because there's a warning that says "Unable to read the contents of this filesystem! Because of this some operations may be unavailable." Umm...what do I do? Digger3000 (talk) 07:41, 9 May 2009 (UTC)

Can't give you any advice about GParted, but you asked what to do... The message sounds like something is inconsistent in the file system, so the very first thing I would do (which you may have done already), is to is to back up immediately to a usb disk. I would do both a backup at the file-level, and back up the partition(s). I use both Partimage (free as in speech) and The Seagate Disk Wizard (free as in beer) for partition-based backups. The latter works if there's a Seagate disk in your system. It's based on Acronis True Image, which of course is an alternative, along with those listed at List of disk cloning software. --NorwegianBlue ^talk 08:24, 9 May 2009 (UTC)

It might help other editors who want to help, if you told us how you have partitioned your disk. Did you buy a PC that came with two partitions, or have you set them up yourself, and if so what software have you used, how many partitions, which file systems? Mixing windows-based and linux-based partition managers is not a good idea, as they tend to have different opinions about where the exact boundaries between partitions go (something I've learned the hard way). --NorwegianBlue ^talk 08:49, 9 May 2009 (UTC)

Yes, I bought my PC and it came with two partitions. I want to dual-boot Windows XP and Windows 7 RC. The guide I googled on how to do that specifically mentioned GParted Live. Digger3000 (talk) 09:20, 9 May 2009 (UTC)

Try running chkdsk /r inside the command prompt in Windows XP. Disk errors will trip up partition editors.--67.174.107.10 (talk) 09:31, 9 May 2009 (UTC)

Don't know anything about GParted, but see List of disk partitioning software for a list of other software you might try if you're unable to get anywhere with GParted. Note that you probably have to boot from a different drive to repartition - you didn't mention whether you're doing that currently. Tempshill (talk) 16:48, 9 May 2009 (UTC)

The last time I tried, gparted didn't support ntfs out of the box. ntfsprogs is the relevant package to install (under ubuntu/debian), but then it would be weird if they didn't have that on a live cd. Have you tried mounting the partition and checked it's not mounted when you are trying to resize? --194.197.235.70 (talk) 14:14, 10 May 2009 (UTC)

Detect that I am running on terminal-only PC (BASH)?

Resolved

Is there a way to detect if a program is running on a terminal with no GUI? (example: computers with no GUI, tty1-6, etc...) I am not talking about "graphical terminals" like gnome-terminal or konsole __ Thanks __ Hacktolive (talk) 11:13, 9 May 2009 (UTC)

Look at the output of the 'tty' program. If the tty is tty1, you know you're on the first console tty. Xterms look like /dev/pts/1, and serial consoles look like /dev/ttyS0, for example. Also, if there is no X session available, then the $DISPLAY variable will not be set. -- JSBillings 13:05, 9 May 2009 (UTC)

But that would fail on BSD. --grawity 18:17, 9 May 2009 (UTC)

I'd go with checking $DISPLAY, as suggested above. --Sean 14:19, 11 May 2009 (UTC)

both the tty and $DISPLAY seem to work. thanks people. Hacktolive (talk) 00:57, 14 May 2009 (UTC)

Easier way to resize an image view?

Whenever I view an image my browser makes it fit within my browser window. Sometimes when I place my cursor over the image it automatically turns into a zoom tool (a magnifying lens with a plus sign in it when over the unmaximized image and a minus sign when its over the maximized image). When that happens I can get the image to enlarge with a single click. However, Sometimes, it doesn't do that but instead the image is just fixed at a certain size. If I want to enlarge, the only way I know is by going to view → zoom → zoom in, and I have to do that multiple times to get to the largest image size available. This is using Firefox, which is the only browser I use. When I do that it causes a secondary problem. For whatever reason, once I've done that laborious zoom process, subsequent web pages I open are sometimes all zoomed up and I have to reverse the process to make them normal. Can someone explain a better way; and easier method for zooming in; anything else relevant to cure my ignorance on these issues? Actually I just checked and I should clarify one error in my writing. Actually when I go to a large image and get the magnifying glass and maximize, I can also zoom even closer from there, so is it maybe that images have a default size range and anything after that has to be done manually or something?--70.19.69.27 (talk) 13:17, 9 May 2009 (UTC)

The magnifying glass goes back and forth between fit-to-window and pixel-for-pixel. If you don't get a magnifying glass it's because the pixel-for-pixel image is small enough to fit in the window already. You can use Ctrl = to zoom in, Ctrl - to zoom out, and Ctrl 0 to return to the original zoom level (either fit-to-window or pixel-for-pixel, depending on how many times you've clicked the magnifying glass). The zooming controls affect all of your tabs/windows, but the magnifying glass only affects the current image. Yes, it's confusing. -- BenRG (talk) 13:47, 9 May 2009 (UTC)

Aha! Cntrl+ solves my problem. Thank you. I can click that five times in about a second and undo it with cntrl- in the same time. Doing it by going through menu functions was such a pain.—70.19.69.27 (talk) 14:08, 9 May 2009 (UTC)

In general, whenever something is too tedious to do using the mouse and the menu - look at the actual words in the menu - very often, they list the keyboard shortcut right there. In this specific case, when I drop down the Firefox View/Zoom menu - I see:

  Zoom In   Ctrl++
  Zoom Out  Ctrl+-
  -----------------
  Reset     Ctrl+0
  -----------------
  Zoom Text Only

which contains the very answers BenRG gave you here! SteveBaker (talk) 17:48, 9 May 2009 (UTC)

Converting FLV to MP4

So, I have a Sony-Ericsson W760, and I want to put some videos in it - but those videos are in FLV (Flash Video) format. How do I convert them to something that's understandable by my phone? (That would be 320x240 MPEG4 video, and AAC LC audio.)

I have tried using mencoder to do that ( -oac faac -ovc lavc -lavcopts vcodec=mpeg4 -of lavf -lavfopts format=mp4 ), but the phone doesn't like that.

I have tried using QuickTime's Export command, but QT doesn't support .flv :/

Any ideas? (Preferably either mencoder, or something free and without {spy,ad}ware.) --grawity 18:26, 9 May 2009 (UTC)

Ah, addition. I'm on Windows XP. --grawity 10:41, 10 May 2009 (UTC)

What kind of computer are you using? If a Mac, try iSquint. You can also get Perian, which allows QuickTime to understand FLV. --98.217.14.211 (talk) 22:21, 9 May 2009 (UTC)

I use MediaCoder for all this conversion stuff. It supports every format I've ever needed, and runs quite well under Wine. Indeterminate (talk) 22:31, 9 May 2009 (UTC)

ffmpeg —Preceding unsigned comment added by 82.44.54.169 (talk) 23:03, 9 May 2009 (UTC)

How does google work?

I often amuse myself by typing stupid things into google to see what the results are. Today I was messing around adding "iggity" sounds before words; when I typed 'jiggity Joe Louis' the first result was the wikipedia page for Joe Louis, which does not contain the "word" jiggity. What's going on? 86.8.176.85 (talk) 22:28, 9 May 2009 (UTC)

Weird. The general idea behind this kind of thing is googlebombing, where the words people use to link to a page get associated with that page in google (accidentally or intentionally). I have no idea why Joe Louis would be associated with 'jiggity', though. Indeterminate (talk) 22:35, 9 May 2009 (UTC)

See PageRank. In short, Google and other search engines hive the highest ranking to pages that contain all of the search words (or variants of those words), but will also find pages that contain some, but not all of the search terms. -- Tcncv (talk) 22:37, 9 May 2009 (UTC)

(ec)Actually the above was not such a good reference. However, on the Google Search Basics page, the Exceptions to 'Every word matters' section contains the statement, "A particular word might not appear on a page in your results if there is sufficient other evidence that the page is relevant." -- Tcncv (talk) 23:05, 9 May 2009 (UTC)

Google doesn't guarantee to find pages with ALL of the words you ask for (even if you use the "advanced search" option that tells it to do that). So it couldn't find ANY pages with "jiggity" and "Joe" and "Louis" - so it looked for pages with "jiggity" and "Joe" (and it actually found one - a YouTube page here... or "Joe" and "Louis" (it found plenty of articles - and the Wikipedia one had the highest page-rank) ... or "jiggity" and "Louis" (which there are plenty of - but none with the page-rank score to beat a Wikipedia entry. SteveBaker (talk) 23:02, 9 May 2009 (UTC)

"These search terms are highlighted: joe louis These terms only appear in links pointing to this page: jiggity" chocolateboy (talk) 05:08, 10 May 2009 (UTC)