I would like to check if there is any occurrence of an uppercase or lowercase string in this:  test strings  1a 2A 3aC   js  const str = '1a' /[a-z]/.test(str) //Pass /[a-z][A-Z]/.test(str) //Fail /[a-z]/.test(str) //Pass
I don't really understand regular expressions.  Can you explain them to me in an easy-to-follow manner?  If there are any online tools or books, could you also link to them?
I have a mouse with lots of buttons, but it's not a mainstream make like Logitech. For Windows, I have a driver that lets me assign actions like close-window (Ctrl+W) or next-tab (Ctrl+Tab), but I don't have a Linux driver. Since Linux is so flexible, I thought perhaps there is a general way to do this, regardless of brand?  Update: Based on input from Cyrex, I installed and ran sudo apt-get install btnx which found several but not all mouse buttons. Found: left, right, wheel, wheelclick, thumb fwd, thumb back. Not found: wheel left, wheel right, thumb middle button. Vendor ID is 0x04d9, Model ID is 0xa015.  Update 2: In System>Prefs>Mouse there's a lightbulb icon for testing double-click speed. Every working button can turn the bulb on&amp;off, but the missing buttons can't. It would seem that Ubuntu isn't aware of these buttons and thus doesn't register their clicks. I guess I need to hunt for a driver, though a mainstream mouse is probably the easier way. How to check if sed has changed a file Suppose I installed ubuntu with the user usr1 then I added usr2. I then create a group grp1 where this 2 users are added. A folder is owned by usr1 and has group grp1. But when I login as usr2 I cannot write. The folder has permissions 755...  usr2@kmserver:/media/data/www$ groups usr1 usr1 : grp1 ... usr2@kmserver:/media/data/www$ groups usr2 usr2 : grp1 ... usr2@kmserver:/media/data$ ls -l total 20 drwx------ 2 root root 16384 2011-05-12 10:53 lost+found drwxrwxr-x 2 grp1   grp1    4096 2011-05-12 15:15 www   Whats wrong? QGIS locked into fullscreen mode on Ubuntu 12.04 How to use a proxy on the command line? I can set my proxy username and password along with proxy settings in the proxy ui but these settings do not work on the command line. How can I use apps such as wget &amp; ping on the command line with a proxy?  Example Details:   username: 1234 pass: linux proxy: proxy port: 8080 Is abstract algebra (mostly?) restricted to $2$-ary operators? This may be due to my own pure ignorance but it's my experience that all abstract algebra I've been introduced to, both in actual courses and in self-studies only exclusively deals with algebraic objects consisting of a set together with one or more binary operators defined on that set, perhaps over some other algebraic structure. Not counting categories here, just "low-level"-ish stuff.  I'm an undergraduate so my knowledge is of course very limited but I can't help to wonder why I never stumble upon algebraic structures with $n$-ary operators? Is there a good reason for this, something along the lines of $n$-ary operators behave "badly" when $n&gt;2$ or is it just my ignorance because I'm a beginner in the field? linq: order by random What's the best counter strategy against battlecruisers? How should I prepare my army when attacking someone who has 12+ battlecruisers? (Protoss/Zerg/Terran answers are more than appreciated) A deck of 52 cards is shuffled, and we deal a bridge of 13 cards. Let $X$ be the number of aces and $Y$ be the number of spades. Show that $X$, $Y$ are uncorrelated.  Here is what I did:  $Cov(X,Y) = E[XY]-E[X]E[Y]$   uncorrelated means $Cov(X,Y) = 0$, hence  $E[XY]=E[X]E[Y]$   $E[X] =  \sum_{k=0}^{k=4} k \frac{\dbinom{4}{k} \dbinom{48}{13-k}}{\dbinom{52}{13}} $   $E[Y] =  \sum_{k=0}^{k=13} k \frac{\dbinom{13}{k} \dbinom{39}{13-k}}{\dbinom{52}{13}} $   Are the summations above correct? and how do I calculate $E[XY]$? Subsurf Modifier artifacts So I was messing with Subsurf modifier to create a certain sword and then some weird artifacts began to appear (cape-like). I've tried adjusting the Crease, but couldn't achive what I wanted. Basicly, what I whant is the as on the screens, but wo any artifacts :)   Also, here's the .blend file, cause I assume I didn't make myselt 100% clear. SO Blog icon has partial white background when tab is inactive When you open a tab on the , and switch to another tab, the icon has a partial white background: Firefox (Most obvious) - note the difference between that and the normal Stack Overflow logo  IE  Edge  Tested on Windows 10 with Firefox 41.0.2, Internet Explorer 11 and Microsoft Edge v20.10240.16384.0. (If someone could test this on chrome that would be great) I am using a mirror modifier for modelling. When viewing the mesh in edit mode, the vertices in the center are firmly stuck together and cannot be separated.     When in pose mode, I manipulate a wrist bone on my model and the mesh splits in two along the mirror axis center.    I have tried removing the subsurface modifier to see if this was the problem leaving only the armature at the top of the modifier list,i.e. as first modifier (which I am told is the bottom of the stack) and the mirror as the second.  It doesn't separate in edit mode and I've also tried increasing the merge limit to 0.1 and there's no change. Manipulating bones separates the mesh. Young adult book about a boy(?) who gets sent through a portal to another world which is really the distant future Show that $\phi(n)=\frac{n}{2}$ if and only if $n=2^k$ for some positive integer k. I think I have it figured and would like to see if I am on the right track. Thank you. How do I install wine? Can someone please explain how I can install  in the following ways?   By using the package manager? By downloading and installing a pre-built package? How can I determine the current brew package count? I tried to get the number of available brew packages by running  brew search | wc -l   but I don't know how accurate this really is. What do I need to take into account to get a more correct number?  PS: macports lists 19,889 packages online I am already a little bit familiar with Linux distros like Debian or Ubuntu (yeah, very similar) but I wanted to try Red Hat based - CentOS 6.2. I have installed it on my Windows 7 host in VirtualBox and tried to play with it a little. I have come across a small problem, namely: the default eth0 interface is down by default. I use the option with NAT (the virtual machine is 'behind' the host). Even if I bring the interface up with ifconfig eth0 up, it does not work right away. I get this after bringing the interface up: eth0      Link encap:Ethernet  HWaddr 08:00:27:0F:00:8A           inet6 addr: fe80::a00:27ff:fe0f:8a/64 Scope:Link           UP BROADCAST RUNNNING MULTICAST MTU:1500 Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:6 errors:0 dropped:0 overruns:0 carriers:0           collisions:0 txqueuelen:1000           RX bytes:0 (0.0 b)  TX bytes:468 (468.0 b)           Interrupt:19 Base address:0xd020  lo        Link encap:Local Loopback           inet addr:127.0.0.1  Mask:255.0.0.0           inet6 addr: ::1/128 Scope:Host           UP LOOPBACK RUNNING  MTU:16436  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)  virbr0    Link encap:Ethernet  HWaddr 52:54:00:75:C2:9B           inet addr:192.168.122.1  Bcast:192.168.122.255  Mask:255.255.255.0           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0 [root@centos ~]# _  What should be done more to configure the network on CentOS machine? Let $\Gamma$ denote the positively oriented circle of radius $2$ with center at the origin. Let $f$ be an analytic function on $\{z \in\mathbb{C} : |z|&gt;1 \}$, and let $$\lim_{z\to \infty}f(z)=0.$$  Prove that $$ f(z)=\frac{1}{2\pi i} \int_{\Gamma} \frac{f(\xi)}{z-\xi}d\xi,  $$ for all $z\in\mathbb{C}$ with $|z|&gt;2$.  I have no idea how to even start. Any hint will be appreciated. I have a major problem that I hope someone can help with. On my Google Maps feature under my Location History it shows a location that I was never at at any point, but when my wife happened to see that location she doesn't believe me that the GPS could be wrong and pinpoint that location if I was never there.  I was first wondering myself how could that could be possible if I was never there or my phone was never at that location that was 35 miles away from me and second is there any way I could prove the GPS being wrong? Can I contact Google Maps and can they give an official printout of that certain day and every location I was? I really need to prove my honesty to her and hope there is a way. I have written below Wrapper class.  global class BI_VA_AutomationWrapper {      global class BI_VA_AutomationRequest {      webservice String userName;     webservice String emailId;     webservice String buinessUnit;     webservice String orgName;     webservice String country;     webservice String environment;     webservice String myShopNumber;     webservice String BidsId;//for testing     webservice String Type; //for testing  }  global class BI_VA_AutomationResponse {      webservice String responseStatus;     webservice String myShopNumber;     //webservice list&lt;Error&gt; errorMessages;     webservice String  errorMessages;//for testing   } global class BI_VA_Error {      webservice String type;     webservice String message;    }}   And test class is,  @isTest public class BI_VA_AutomationWrapperTestClass  { public static testMethod void unitTest(){      BI_VA_AutomationWrapper.BI_VA_AutomationRequest wrap= new BI_VA_AutomationWrapper.BI_VA_AutomationRequest();        wrap.userName='Test@test.com';     wrap.emailId='Test@test11.com';     wrap.buinessUnit='AH';     wrap.orgName='ORD';     wrap.country='US';     wrap.environment='QA';     wrap.myShopNumber='123456789';     wrap.BidsId='123';     wrap.Type='ResetPassword';              BI_VA_AutomationWrapper.BI_VA_AutomationResponse res= new BI_VA_AutomationWrapper.BI_VA_AutomationResponse();     res.responseStatus = 'Success';     res.myShopNumber = '987654321';     res.errorMessages = 'Test error';      BI_VA_AutomationWrapper.BI_VA_Error error = new BI_VA_AutomationWrapper.BI_VA_Error();     error.type = 'Test';     error.message = 'Test';  }}   Code coverage is 0% only.