I am trying to figure out the list of possible ways to find out if a Linux machine is 32 bit or 64 bit.   Method 1:  The command uname -m will specify if my machine is 32 bit or 64 bit.    Method 2:  I can run the command getconf LONG_BIT to find if it is 32 bit or 64 bit.   Method 3:  I can check for the lm bit in the /proc/cpuinfo file. If that bit is not set, then I can say my machine is a 32 bit machine.   Which of the above methods is the more accurate way of telling if my machine is a 32 bit machine or 64 bit machine? Or is there any other efficient way/command to find out the same?
I'm confused. Running Fedora Linux, lscpu yields:  Architecture:            i686 CPU op-mode(s):          32-bit, 64-bit ...   But when I try to install a 64-bit program (Chrome) I get error like:     Package /....x86_64.rpm has incompatible architecture x86_64. Valid architectures are ['i686', 'i586', 'i486', i386']   I'm less interested in being able to install Chrome and more interested in why lscpu says that my CPU can run in 64-bit mode; clearly this can't mean I can run 64-bit programs. Can anyone clarify?
I am trying to put a server together to install Ubuntu. I bought an Intel S1200v3RPS motherboard and plugged an Intel Xeon E3 processor into it. I purchased a 1U chassis from Supermicro with a power supply.  The power supply does not have a 5-pin cable to the motherboard's Auxiliary Power Supply socket. A bit of research did not give any definite answer on the need for the 5-pin connection. The motherboard does not power on and the CPU fan is off. I tested the power supply on a desktop Intel motherboard and it works fine.   I would like to buy a new power supply but could not find one which expressly stated that it comes with the 5-pin aux power supply cable. Any recommendations on a power supply unit for this motherboard would be helpful. Any comments on the problem would be greatly appreciated. Prove the following $A \setminus (B\setminus C) = (A\setminus B)\cap (A \cup C)$ I want to prove the following so I decide to rewrite the RHS  $$A \setminus (B\setminus C) = (A\setminus B)\cap (A \cup C)$$ $$ A\setminus(B\setminus C) = A\setminus (B \cap C^c) = A\cap (B\cap C^c)^c = A\cap(B^c\cup C) = (A\cap B^c)\cup(A\cap C) $$ there is way that $(A\cap B^c)\cup(A\cap C)\rightarrow (A\setminus B)\cup(A\cap C) = (A\setminus B)\cap (A \cup C)$?  thanks. EDIT  LHS: $$x\in A \vee x\in A\cap C \rightarrow x\in A \wedge x\in C$$ RHS: $$x\in A \wedge x\in A\cup C \rightarrow x\in A \vee x\in C$$  how it can help me? I need to match a space character in a PHP regular expression. Anyone got any ideas?  I mean like "gavin schulz", the space in between the two words. I am using a regular expression to make sure that I only allow letters, number and a space. But I'm not sure how to find the space. This is what I have right now:  $newtag = preg_replace("/[^a-zA-Z0-9s|]/", "", $tag); How to use Launchctl for schedule application I try to work with Launchctl and have a question:  How can I set up an application to run in a few minutes using Launchctl? (for example, open the program MyApp.app with arguments "hello" "world" Every 10 minutes)  I know that it can easily be done by creating Launch Agent, I looking for a way to do it using Launchctl directly to programmatically. How to identify hardware performance bottleneck in laptop? Is there any tool that helps to determine the weakest link of my current laptop hardware specification? Any online guide to help me choose nice balanced configuration for the new laptop?    I need to find the answers:  a) which component should be invested to increase overall performance the most? CPU? GPU? RAM?  b) which component may decrease overall performance and work as a bottleneck for the specific configuration?    The question is general and regards both to validating the current hardware usage (and its possible bottlenecks) and estimating the performance (and avoiding possible issues) of specs I'm going to choose and buy.    P.S. For the specific laptop I need to replace, the following software will be in use:    Windows antivirus, firewall, dropbox service running in the background mail app + web browser with a dozen or so tabs open from time to time: libreoffice apps, movies, games (both online and installed). ctrl + a doesn't work in browsers The combination for select all (Ctrl+A) doesn't work in a browser (either if we speak about firefox or chromium). It doesn't work if I try to clik in to the adress bar nor if I try to use it to select what I've written in google search bar at google.com. When I press Ctrl+A it simply takes the cursor before the first letter.  This doesn't happen when I use a text editor software like Libre Office. There the shortcut does what's supposed to do, selecting all the text.  What could be the problem? Gaussian integral evaluation Asked a question to evaluate the Gaussian Integral,  $$\dfrac{1}{\sqrt{2\pi}} \int_{-\infty}^\infty x^2 \exp(-x^2/2) dx  $$  using the the following approximation,  $J=\Bbb E[X^2] \sim J_N = 1/N \sum_1^NX_n^2 $  where $x_n \sim N(0, 1)$  Examin $J_N$ for different values of $N$ and plot an error graph (difference between exact and numerical values)  I can simulate and generate the approximations but I am stuck at getting the exact value to compare to. As far as I am aware there are no analytical solutions for gaussian integrals. The other way I can generate comparable numbers is to go use numerical integration techniques but those are approximate values too.  Any help will be greatly appreciated! Which preposition should follow "guide" here, "on," "to," or "for"? The following link includes a guide ___________ how to use it.  How should I fill in the blank, on, for, or about? When may adjectives precede determiners? (E.g. too difficult a task) The expression too difficult a task sounds a little pompous, but it doesn't sound ungrammatical. According to my folk-beliefs about English grammar, determiners precede adjectives. However, the expression too difficult a task seems to controvert that belief.  Additionally, the expression too difficult of a task seems grammatical too.    Under what conditions may determiners precede adjectives? Are there conditions under which too difficult of a task would be a more grammatical expression than too difficult a task would be?   (This question does not ask what the question “How big of a problem” vs. “how big a problem” asks. That question does not pertain to determiners.) What is the product of the empty set? Give:  $fn(S)=\prod_{x\in S}x$  what is:  $fn(\emptyset)$  I can see reason that it would be defined as 1 or 0.    Note: I thought about restricting the domain of $S$ but that would make the problem less general. If there is no general answer then answers for restricted domains would be valid. How to convert java.util.Date to java.sql.Date? I am trying to use a  as input and then creating a query with it - so I need a .    I was surprised to find that it couldn't do the conversion implicitly or explicitly - but I don't even know how I would do this, as the Java API is still fairly new to me. JUnit @Test expected annotation not working Power Supply Capacity Formula Given that I am building a home computer from scratch and I have several components (MB, CPU, HDD, Video, Sound, etc) which have specific power requirements, is there a formula for me to calculate the size/capacity of the Power Supply I will need? I want to be able to expand the setup later on also... How to create a table with long text and which packages use Why I can't connect to VPS after changing OS from CentOS to Ubuntu? For example, you're a fashion designer who wants to get the opinion of both a professional and someone who doesn't know much about fashion. What's a term for the latter person? Help us test the alpha version of our Android app We are in the early stages of development of the official Stack Exchange Android app and we need your help with testing. To set a few expectations: there will be bugs, crashes, and missing features, all of which will be fixed in .    We are initially targeting Android devices running  (Android 4.1 or higher) starting with phones (up to ~5 inch) and eventually moving our way to tablets.    To register for alpha testing .  After you register we will send you an invite to a private Google community where you can find a link to download our app directly from the  store. The invitations will be sent out in waves, so if you don’t get an invite immediately, be patient.  Crash reports will be automatically reported back to us using . Bugs or feature requests should be reported here on meta and tagged . Please do not use the Google community to report bugs.  As always, we welcome your feedback and are committed to building the best mobile app possible for browsing the Stack Exchange sites. I need to print an image at a certain size. What dimensions and resolution should I use? Why is the Finder app always open? First time Mac user. I am confused by the fact that the finder application is always open. For example, when switching apps with Cmd+Tab, it is always there, even when there are no windows opened for the app. Cmd-tabbing to Finder with no windows/tabs opened for it has no effect (it seems to me it would more intuitive to open a new tab when this action is chosen).   Furthermore, there is no 'Close app' option when I right click the Finder icon in the dock. Am I misunderstanding something about the Finder app? Is it required for proper functioning of Mac OS? From what I see, Finder is just a file browser, which by no means should be forced to be open 100% of the time. Latest NVIDIA driver on Ubuntu 16.04