Wikipedia:Reference desk/Archives/Computing/2010 March 13

= March 13 =

Best inkjet printer for occasional use and refilling
I have a 5 year old Canon Pixma IP3000, which I used about once or twice per month. The current set of cartridges may be about 3 years old; I refilled them regularly. Now they are clogged, and deep cleaning doesn't help. I would have bought a new set of cartridges, but since I also begin to get paper jams, it's time to buy a new printer. I checked out Consumer Reports (to which I'm subscribed), but they only look for print quality, speed, and price per page. I don't care about price per page, and speed isn't much of an issue for me, either. Is there any review for what matters in my case, or does anyone have a recommendation? &mdash; Sebastian 01:41, 13 March 2010 (UTC)


 * Pretty much every printer I've ever had has had problems with paper jams, but feeding in paper one sheet at a time solves the problem, for me. Many have also had more serious problems, so I consider myself lucky when I get a printer that only jams. StuRat (talk) 01:57, 13 March 2010 (UTC)


 * Thanks, StuRat. Actually, the jamming is pretty bad now; I went to the local hardware repair service with it, but they said they couldn't fix it for the price for which you get a new one. I do want to avoid waste, and it goes against my grain to buy a new product instead of fixing the old one, but in this case it looks like I have to bite the bullet. Also, I do want to look out for a printer that takes better to the occasional use. The Pixma kept saying that it's low on ink just from sitting there, and I kept refilling it almost every time I used it, which freaked me out because I don't know where the ink went, if not on the paper. (The printer has a sponge that collects ink, but I'm not sure if that's where it went as it's hard to reach and not meant to be emptied or replaced.) &mdash; Sebastian 02:26, 13 March 2010 (UTC)


 * So feeding in one page at a time doesn't stop the jams ? As for the disappearing ink, I'd guess that the cartridge isn't properly sealed, leading to evaporation of the liquid component.  The small solid component then probably dries on the sponge.  Ink drying and clogging the ports is likely to be a problem with any ink-jet printer, so you may need to bite an even bigger bullet and buy a laser printer.  While the purchase price is likely to be much higher, not having to continuously replace dried out ink and cartridges may make it cheaper in the long run. StuRat (talk) 13:31, 13 March 2010 (UTC)
 * No, unfortunately, it still jams. But thank you very much for your explanation; that seems indeed possible. At first, I thought it would be unlikely for the ink to evaporate through some minuscule leak (such as bad sealing of the fill hole), but it's possible that it evaporates from the sponge. Thanks also for the idea of the laser printer; if I used my printer more often, that would indeed be an interesting alternative. (There are some available at $350.) &mdash; Sebastian 02:34, 15 March 2010 (UTC)


 * As with most specialist questions of this sort, you may want to check out a more dedicated forum. In particular, I was looking in to refilling my catridges recently and found was often recommended as a place to check out & seems to have useful information & quite a lot of people who have experience.  may be useful as well although I never really visited it.
 * FWIW, I found Canon printers were often recommended (except perhaps for CISS), although this may be influenced by the fact that I have a Canon printer and have a degree of bias towards them (liking their policy of individual ink catridges as well as avoiding chipped catridges for so long and even when they had them not generally completely preventing you from using unreset refilled catridges but simply warning and then recording in the EPPROM if you do followed by disabling monitoring). Canon also tend to have translucent catridges making manually monitoring the ink level and refilling easier and usually have removable print heads so you can try cleaning them if they clog which often works a few times I believe (buying new ones is possible but unlikely to be worth it).
 * Epson tend to have a reputation for worse clogging and similar problems particularly if you don't print often and are also know for their chipping practices (usually preventing you from printing if the catridges is refilled or expired) & generally strong stance against remanufacturers & third party catridges & chips including DMCA and patent infringement lawsuits. They do have a reputation for their photo quality particularly on special media which is probably the main reason they do receive a fair amount interest among refillers despite their problems.
 * HP don't seem to receive so much attention, although their printheads included with catriges would seem to be an advantage to those worried about clogs and for casual users. Not sure why but it may be because they've generally been closer to Epson in the way they've dealt with third party catridges and refills (e.g. chipped catridges refusing to work if refilled or expired, suing manufacturers although I don't think they've gone the patent route yet) and generally lack individual ink tanks and haven't had a reputation for quality so the only reason of interest is likely to be the print heads in catridges.
 * Never paid much attention to Lexmark but they don't seem to have been of much interest to refillers either, they're perhaps like HP but worse they don't even have their printheads built in to catridges.
 * In other words for my mostly uninformed opinion it'll probably come down to Canon or HP but I would recommend you research more first. I do know that if you do decide on Canon, the IP4500 which still uses the older CLi8/PGI5bk catridges would probably be better if you can find it then the newer IP4600 which uses the CLi521/PGi520 as the new catridges are smaller and resetters and third party chips are newer and likely to be more expensive (and therefore the 3rd party catridges too) although this may not matter to you. It's still available here in NZ & of course is cheaper too although we tend to be behind & it isn't available at NewEgg (however perhaps retail stores will have it cheap).
 * Particularly since you appear to live in the US, you may also find it worthwhile checking out recommended suppliers of ink, some are better then others. Also methods of refilling.
 * Nil Einne (talk) 03:47, 14 March 2010 (UTC)
 * Thanks for your exhaustive tips! I'll have to check into the forums and good idea about checking ink suppliers. I wouldn't mind buying a Canon again; generally, I liked my old printer, and more friendly policies is something I want to reward. It didn't even occur to me that other printers might not have transparent cartridges - that's just so low! &mdash; Sebastian 02:34, 15 March 2010 (UTC)

Hex line numbers
How can I add hexadecimal line numbers to the beginning of each line in a text file? I know that nl can do this for decimal line numbers, but is there a way to use awk, sed, or some other command to do this? I'm hoping to take a text file like this: First line Second line Third line ... Ninth line Tenth line

And turn it into something like this:

0x01 First line 0x02 Second line 0x03 Third line ... 0x09 Ninth line 0x0A Tenth line

or this:

01 First line 02 Second line 03 Third line ... 09 Ninth line 0A Tenth line Daram.G (talk) 15:24, 13 March 2010 (UTC)
 * awk 'BEGIN { n = 1 } { printf("0x%X %s\n", n, $0); n++ }'. I don't know if there's a way to force the number of digits to be a multiple of two. --194.197.235.240 (talk) 16:19, 13 March 2010 (UTC)
 * Wow, that worked like a charm! Thanks a lot. Daram.G (talk) 18:45, 13 March 2010 (UTC)
 * Awk maintains a line count in the variable NR ("number of records"), so a simpler version of that program would be:

awk '{ printf("0x%X %s\n", NR, $0) }'
 * --Anonymous, 05:16 UTC, March 15, 2010.

Using sed is harder but this "program" is derived from section 4.7 of the sed info examples: sed -e 'x /^$/ s/^.*$/1/ G h s/^ *\(.*\)\n/\1 /p g s/\n.*$// /^F*$/ s/^/0/ s/.F*$/x&/ h s/^.*x// y/0123456789ABCDEF/123456789ABCDEF0/ x s/x.*$// G s/\n// h' file-name

One bug I have is the line number comes out twice. Graeme Bartlett (talk) 04:41, 14 March 2010 (UTC)

MediaWiki LocalSettings.php -- setting up Guest read-only account.
I'm setting up a wiki which requires being logged in to view any page except the login screen. In addition to the ordinary editor and admin accounts, I would like that there be an account called "Guest", that is allowed to view any page, incuding its source, but not to edit anything. How do I accomplish the last requirement? Here's what I've got so far:

$wgGroupPermissions['*']['createaccount'] = false; $wgGroupPermissions['*']['read'] = false; $wgGroupPermissions['*']['edit'] = false; $wgWhitelistRead = array("Special:Userlogin", "-", "MediaWiki:Monobook.css");
 * 1) Prevent new user registration except by sysops.
 * 1) Require login to view anything

Thanks, --NorwegianBluetalk 15:29, 13 March 2010 (UTC)


 * Add this to LocalSettings.php (in addition to what you already have):
 * $wgGroupPermissions['user']['read'] = true;
 * $wgGroupPermissions['user']['edit'] = false;
 * $wgGroupPermissions['editor']['edit'] = true;
 * and then add all accounts you want to be able to edit to the "editor" group (the default WikiSysop account should have the rights to do that). You can create a Guest account and not add it to the editor group to get your desired functionality. You may also want to give some additional users the right to create accounts and make them editors - I think bureaucrats will be able to do that by default. mw:Manual:User rights management gives more information on this topic. --Tango (talk) 05:38, 14 March 2010 (UTC)
 * Thanks a lot! Worked perfectly. What I hadn't understood before reading your reply, was that I could add new groups in LocalSettings.php myself. --NorwegianBluetalk 11:48, 14 March 2010 (UTC)

Dell function keys
My new Dell Studio's default behaviour is for e.g. F5 to increase the screen brightness and Fn + F5 to be the 'real' key, opposite to every other laptop I've used. This is very annoying. There was a thread on here recently talking about how to toggle this to the reverse, but I can't find it. How? Thanks 94.168.184.16 (talk) 20:20, 13 March 2010 (UTC)


 * Entering dell function into the little search box at the top of the page produces this: --Phil Holmes (talk) 10:44, 14 March 2010 (UTC)


 * Ta. 94.168.184.16 (talk) 13:12, 14 March 2010 (UTC)

Single page PDFs > Online accessible format
My local archives did a massive project a few years back, scanning a dozen Tweedsmuir Histories. They're saved as individual PDFs, and each is high-resolution. (300 dpi, 18" x 24" or so, 100%.) Similarly, the local library system scanned a whole series of books by a 1930s historian. In both cases, the scans are somewhat useless, it's easier to just pull out the real book.

Is there any sort of website that these could be uploaded to, to be viewable in a format similar to Google Books? I've found various sites where people can publish magazines online, complete with the whole flippy page bit, but nothing free or cheap... they'd have to apply for a grant if it cost too much. -- Zanimum (talk) 21:40, 13 March 2010 (UTC)


 * Scribd; that article also links to some of Scribd's competitors. -- Finlay McWalter • Talk 21:48, 13 March 2010 (UTC)


 * You can also upload them to Google Books; it seems to need to sign up to be a Google Books partner. -- Finlay McWalter • Talk 21:53, 13 March 2010 (UTC)


 * Both options are only good if you have only one file to upload. Sadly, all 300 or so pages of each of the dozen books is a separate PDF. I can find a merge program easy, but the resultant file would crash a supercomputer. (I exaggerate, but it would be unwieldly.) --  Zanimum (talk) 22:09, 13 March 2010 (UTC)


 * I've merged some very large PDFs (full of scanned images) with PDFTK without issue. PDF readers are fairly smart (and one would assume those used by Scribd and Google Books are smart too) - they only load so much of a document into memory, so you can have a very large PDF without breaking things. -- Finlay McWalter • Talk 22:16, 13 March 2010 (UTC)


 * (Granted, I suppose I wouldn't actually need to open the merged PDF, if its only reason for being was to be uploaded.) --  Zanimum (talk) 22:11, 13 March 2010 (UTC)


 * Are they somewhat useless because the files take so long to load, and because they haven't been OCR'd? Because the simplest solution to that is to OCR them, and reduce or eliminate the photographic data itself (offer separately / upon request?).  If they're not encumbered by copyright, etc., you could upload them to Wikisource or Project Gutenberg.  I'd probably remove the photographs from the PDFs beforehand. ¦ Reisio (talk) 22:01, 13 March 2010 (UTC)


 * All of the OCR programs I've tried don't work. And as far as I know, I've tried all the free licensed ones mentioned on Wikipedia, plus more. Any recommendations? As for copyright, the 1930s books will be OK in a year or two, but the Tweedsmuir histories are a mess of orphaned works.  --  Zanimum (talk) 22:09, 13 March 2010 (UTC)


 * I've uploaded old books to the Internet Archive. All you have to do is create an account and you'll be able to upload the pages in whatever format you want. Also, when you say the programs didn't work, do you mean that the OCR program interpreted the characters incorrectly? I've found ABBYY FineReader does better at mitigating that than other programs. Also, I've found that it helps to increase the resolution above 300 DPI when the characters are very small.--Chmod 777 (talk) 22:16, 13 March 2010 (UTC)


 * If it were me (and I've been in a similar situation with my own records), I'd first 1. try to find a way to download all the PDFs at once (maybe using a spider), 2. use PDFTK+ImageMagick to compress the individual PDFs into something reasonable (e.g. reduce the colors, to black and white if possible), 3. use PDFTK to combine the resultant files (takes forever, but won't crash a supercomputer, no—probably would take an hour or five on a modern computer), then, 4. maybe try an OCR program (whether it works depends on a lot of factors relating to the originals), 5. upload them to ScribD or something like that. --Mr.98 (talk) 22:21, 13 March 2010 (UTC)


 * Note that Scribd has an API which can do uploads; you should be able to find a library that talks the API for several popular programming languages (there's certainly a python one) which would automate the upload of your many files (heck, add an os.walk call to the python example and you're mostly done). -- Finlay McWalter • Talk 22:26, 13 March 2010 (UTC)


 * And Google Docs has an API likewise - here -- Finlay McWalter • Talk 22:27, 13 March 2010 (UTC)


 * If these are solely black and white text, perhaps with some simple diagrams, consider converting them to 1 bit and compressing with JBIG2 or perhaps CCITT Group 4 compression if you want compatibility with PDF older then 1.4. The resulting PDFs shouldn't be too large especially since they're only 300 DPI. If they have colour, photos or complicated diagrams on some pages only, you can handle those seperately. Nil Einne (talk) 02:53, 14 March 2010 (UTC)


 * If they are of general public interest, please put them on the Internet Archive via here. They do all kinds of format conversions and OCR'ing automatically too.  I can't stand scribd because you have to sign up for an account just to read stuff. 66.127.52.47 (talk) 08:52, 14 March 2010 (UTC)


 * I can't stand its UI, either... ¦ Reisio (talk) 08:57, 14 March 2010 (UTC)