Wikipedia:Reference desk/Archives/Computing/2011 October 29

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October 29

Caller ID history

Does anyone know an app that does this? I'm using an Android phone, and I'd like an app which displays the recent history of an incoming call while it's incoming. This is because I run a substantial amount of business through my phone, and it's useful to see if I've had dropped calls from this person before or if I've picked up for this person before. Magog the Ogre 2 (talk) 01:32, 29 October 2011 (UTC)

irc.freenode.net's #android channel would be a good place to ask, though you must first register & identify with the network's nickserv. ¦ Reisio (talk) 11:05, 29 October 2011 (UTC)

Parameter passing

Please see Q. 22 (b) (ii). I don't understand why the passed parameter (fingers) is necessary. Would it not be possible to forget about the parameter and transform the function CountFishFingers into a procedure which initialises fingers = 0 at each execution? So you'd have

BEGIN MAINPROGRAM PackFishFingers
WHILE system_on = true
ScanCarton(scan) 
IF scan = true THEN
CountFishFingers
CloseCarton
ENDIF 
ENDWHILE
END MAINPROGRAM

BEGIN SUBPROGRAM CountFishFingers
fingers = 0
WHILE fingers < 100
ScanChute(scan)
IF scan = true THEN
fingers = fingers + 1 
ENDIF
ENDWHILE 
END SUBPROGRAM

That seems legitimate, so why is a pass necessary? —Anonymous Dissident^Talk 07:30, 29 October 2011 (UTC)

Why would you bother to count the fish fingers if you are not going to do anything with the number you get? Looie496 (talk) 15:07, 29 October 2011 (UTC)

Perhaps I'm not understanding the way ScanChute works, but it seems to me that within the subprogram CountFishFingers, scan is only going to be true (and fingers will only be incremented) when a fish finger falls. So it is doing something. —Anonymous Dissident^Talk 20:52, 29 October 2011 (UTC)

Well, yes, that's presumably the answer you're supposed to give - you have just completed the required task "Analyse the necessity for passing a parameter to CountFishFingers", and the result of your analysis was: "I don't understand why the passed parameter is necessary." That's probably right. By the way, if scan is a global variable then passing that isn't necessary either, and if it isn't a global variable then the pseudocode must be using a paradigm of Pointer_(computing)#Pass-by-address_using_pointers Evaluation strategy#Call by reference, without giving any indication of this to the reader, which is byzantine not what I'm used to. Fortunately this makes no difference to the questions (assuming that when asked to give their types in question (i), you just respond with "boolean" and "int" and let their scope remain ambiguous).  Card Zero  (talk) 19:46, 31 October 2011 (UTC)

Yeah, "analyse" is ambivalent, so that could be the way of it. We haven't learned specifically about call-by-reference, so it seems that sometimes it's assumed and sometimes not. (Call-by-reference is where you call a function with a variable and afterwards the variable is changed, right?) —Anonymous Dissident^Talk 21:08, 31 October 2011 (UTC)

Yes, that's call-by-reference.  Card Zero  (talk) 22:10, 31 October 2011 (UTC)

Question about a line in fstab (Linux)

Hi. My fstab has a line beginning "Label=/boot"; is the boot partition the device usually referred to by this label? I'm salvaging a really damaged system and when I boot it tells me that there is no such labeled device; so, I figured I could just replace it with actual device name. The os does boot, though. On another matter, the system keeps telling me that various hardware components have been removed and that there configurations remain; could this be related, if not, any ideas? The os is redhat; not sure which version; I literally started this project with everything basically sitting in lost+found and am needing to restore all the system files where they ought to go (various reasons, I cannot just do a clean install.) Thank you for any help :-) 209.252.235.206 (talk) 09:00, 29 October 2011 (UTC)

Sounds weird. You say it doesn't recognize the line but it still boots? Are you sure the contents of /boot/ (kernel images and the like) are even on a separate partition? (They'd be on the partition you mount for / otherwise). You can make a new label with (for ext filesystems, for example) e2label, or you can replace LABEL=/boot with the device path (/dev/sdX#). Probably take less time and be safer to do a reinstall, though, with CentOS if necessary. ¦ Reisio (talk) 11:11, 29 October 2011 (UTC)

It's not that weird. The bootloader has its own way of finding the kernel image, which doesn't depend on the label, and the only other time you need to access /boot is when you're installing a new kernel. It's plausible that the label, or even the whole superblock, could be mangled but the kernel still boots and everything works except that /boot doesn't get mounted. If this is the case, then you should find /boot to be an empty directory, and you should find a partition in the partition table that doesn't correspond to any mounted filesystem. If on the other hand you have a /boot directory that's full of the correct files and all existing partitions are already mounted, then the label=/boot entry in fstab must be a relic from an earlier configuration that you don't need. 67.162.90.113 (talk) 22:52, 29 October 2011 (UTC)

Merge conflict frequency

How does the number of programmers working on a project affect the rate of merge conflicts and the amount of extra workload resulting from them, under a continuous integration policy? NeonMerlin 09:05, 29 October 2011 (UTC)

The modularity of the project will greatly affect the answer. If the program is modular and programmers mostly work on their "own" parts of the project, assigned by project management, there will be relatively few conflicts. If you have a monolithic program with little project control and planning, well, then you'll have problems. 88.112.59.31 (talk) 14:32, 30 October 2011 (UTC)

Asking for ID and "justificatif de domicile" for buying in the internet

I'm currently based in Spain and I bought via credit card a table (just a bit over 100€) in a French online shop (www.road-plaisance.com) and they want me to give them a "pièce d'identité et un justificatif de domicile" in order to prevent "fraud". I haven't done anything remotely suspicious to expect fraud from me, but whatever. Can I expect this to be a scam or is this just part of normal French online business? --Sinloni (talk) 10:59, 29 October 2011 (UTC)

"pièce d'identité et un justificatif de domicile" or "ID and proof of address". Realistically someone with your credit card information could get your address from it (and besides how are you receiving this table?), so it's not as if you're risking additional personal information. It's possible they're assuming you are currently residing in France (again how are you receiving this table?), and are balked at why your credit information says you're in Spain (etc.). My understanding is that this sort of request comes up in France when dealing with foreigners, but aside from that it does seem like it would prevent fraud in some instances. ¦ Reisio (talk) 11:25, 29 October 2011 (UTC)

Thanks. My guess is that they're doing this in order to prevent someone who got my credit card number somehow from ordering things with my card, could this be? I'm receiving this table via express mail or something like that (can't recall its name). Well, they shouldn't be surprised my credit card says I'm in Spain because I chose Espagne in their drop-down list. --Sinloni (talk) 12:19, 29 October 2011 (UTC)

Yes it isn't uncommon of companies will ask for additional verification often including a photocopy of ID (although some times they just ask for both sides of the credit card) for credit card orders from overseas (using and international credit card) even for physical delivery. For an unsighted credit card order, they're pretty much taking full responsibility for fraud. I've seen this requirement for both US [1] and UK companies so it's by no means unique to France. Ideally they should have told you before you ordered but perhaps they do say so on their website and you just didn't understand it? I'm not of course saying there is no risk of it being a scam, simply that it definitely happens a lot in non-scam cases. Nil Einne (talk) 13:41, 29 October 2011 (UTC)

To their credit, it was in their terms & conditions page. I read like half of it, but it was quite long, so I just skimmed the rest. --Sinloni (talk) 13:47, 29 October 2011 (UTC)

In my experience from a few years ago, the French retailers seem strangely paranoid about foreign credit cards. I was nearly always asked for additional ID when paying for anything by card, even groceries; and they can get very reluctant to let you pay without additional ID. The default assumption seemed to be that you're going to rip them off, rather than you being a genuine shopper. However, in your case I'm curious how they expect you to get the "pièce d'identité et un justificatif de domicile" to them? I presume you are not prepared to travel all the way to Nantes just to show them in person, so if your French is up to it, I suggest phoning them; maybe they'll accept a scan of your passport and Spanish residence permit sent by email. Astronaut (talk) 16:23, 31 October 2011 (UTC)

Don't worry, I have a french credit card, and I was asked once or twice a proof of ID when buying on the Internet. A scan of your electric bill or ISP invoice should do. -- Luk ^talk 16:37, 31 October 2011 (UTC)

Is this a trustworthy site?

Is this a trustworthy site? I have never ordered anything online before and I don't want to give my details to them and have them just steal my money and not deliver the computer. Any advice? Buildingacomputer1234 (talk) 11:41, 29 October 2011 (UTC)

If you're unsure about a site, one way to see if it is trustworthy is to run its URL through Google (put it in quotes). I don't see anything that suggests its a scam, and you'd expect something if there was (people are nothing if not quick to complain on the internet). The fact that they have a reasonably large and active set of forums also suggests to me that they aren't fly-by-night crooks. Caveat emptor, but they seem fine to me. --Mr.98 (talk) 13:47, 29 October 2011 (UTC)

One of the Windows blogs mentions them. It's a bit promotional in tone, so it might just be a press release, but they appear to at least be a legitimate company. Buddy431 (talk) 15:15, 29 October 2011 (UTC)

I generally look for purely negative feedback. Positive feedback is easy to fake and can be misleading. Negative feedback is hard to take down, by comparison. If there aren't lots of people saying, "it's a scam, I lost all my money, etc.", then it probably isn't one. My experience in general is that the internet is biased towards negative feedback (because most people who are satisfied with service don't go out of their way to say so, whereas people who are extremely dissatisfied are often quite motivated to say so), so if you don't find lots of negative feedback, you can at least assume that it's not a total scam. It might not be a good deal, it might not be great, but it's probably not just a criminal front. --Mr.98 (talk) 16:01, 29 October 2011 (UTC)

The Web of Trust Firefox plugin rates the site as trustworthy. --NorwegianBlue ^talk 16:58, 29 October 2011 (UTC)

What the CheckRate link at the bottom of the right side bar is for. ¦ Reisio (talk) 18:01, 29 October 2011 (UTC)

Just wondering, but how would one know if the CheckRate site itself was legitimate? Personally I've never heard of it before. 82.43.90.142 (talk) 19:25, 29 October 2011 (UTC)

That's what the VeriSign link is for. ¦ Reisio (talk) 21:02, 29 October 2011 (UTC)

Certificate_authority#Subversion_of_CA  Card Zero  (talk) 20:23, 31 October 2011 (UTC)

I bought a PC from them and was completely satisfied. --Phil Holmes (talk) 17:33, 30 October 2011 (UTC)

kill

What is the Windows equilvant of

kill <pid>

? I don't want to forcefully kill a program, I want to "soft kill" it, eg tell the program to finish gracefully and then close. 82.43.90.142 (talk) 23:01, 29 October 2011 (UTC)

taskkill without the /f option. -- Finlay McWalterჷTalk 23:46, 29 October 2011 (UTC)