Since upgrading from Ubuntu 16.04 to 18.04 my Epson Workforce 2760 printer will not scan documents. I have tried everything I can find related to this problem with zero success. I have tried installing backends and setting permissions. There are others who are having this problem but perhaps not enough to get to a level that attracts the attention of someone who can help. There may be a bug in the 18.04 version that causes this and hopefully either a workaround or a fix can be discovered soon.   One thing I tried was this:   sudo ln -sfr /usr/lib/sane/libsane-epkowa* /usr/lib/x86_64-linux-gnu/sane   Still no success. Possibly the upgrade to Ubuntu 18.04 broke something within the Sane setup. I don't know how to "provide some more details, like the output for lsusb to prove the scanner is actually attached and recognized."  Found this:   Here is output of "sudo sane-find-scanner" :  # sane-find-scanner will now attempt to detect your scanner. If the   # result is different from what you expected, first make sure your   # scanner is powered up and properly connected to your computer.  # No SCSI scanners found. If you expected something different, make sure that   # you have loaded a kernel SCSI driver for your SCSI adapter.  could not fetch string descriptor: Pipe error could not fetch string descriptor: Pipe error found USB scanner (vendor=0x04b8 [EPSON], product=0x111c [EPSON WF-2760 Series]) at libusb:005:002   # Your USB scanner was (probably) detected. It may or may not be supported by   # SANE. Try scanimage -L and read the backend's manpage.  # Not checking for parallel port scanners.  # Most Scanners connected to the parallel port or other proprietary ports   # can't be detected by this program.
I am trying to get an Epson WF-2760 scanner that is network-connected working. I'm using Ubuntu 16.04.2 64-bit and the printer works a treat. I have installed the Epson drivers from their site, including the plugins. I have edited /etc/sane.d/dll.conf to enable epson, epson2, and epsonds. I have edited each of the respective .conf files to include the network address of the device (IPV4: 192.168.128.11).   The scanner is not detected in any software that I have tried (including Image Scan and Simple Scan).  Any help is appreciated!
Evaluate $\lim\limits_{x\to 1}\frac{\sqrt x-x^2 }{1-\sqrt x}$ What are the scope restrictions for setting shopt extglob. and other options? My non-interactive bash shell has extglob off. I would like to turn it on in the statement immediately before a command, but I have noticed that when shopt -s extglob is within an if .. then .. else block, it somehow does not register.   The following extglob-dependant command is not valid: syntax error near unexpected token '('.     Where can extglob be set, and why is there a restriction, at all? Does this apply to other options?  ... GNU bash 4.1.5     This works:    shopt -s extglob if true ;then     touch a.bcd; ls a.@(bcd) fi   This fails:    if true ;then     shopt -s extglob     touch a.bcd; ls a.@(bcd) fi ... line 17: syntax error near unexpected token `(' ... line 17: `touch a.bcd; ls a.@(bcd)' I have a dozen or so image files on my iMac's desktop.  Most of the time, after booting up my computer, it displays a thumbnail of each image (as it should).  But sometimes, the thumbnails won't show up (see screenshot below).    It appears to happen randomly.  I estimate that it happens about 20% of the time.  Why is this, and how can I prevent it from happening?  I am running OS X 10.9.4.  Thanks. Run a command in a shell and keep running the command when you close the session I am using Putty to connect to a remote server. What I want to know is if there is any way to write my commands and allow them to keep running after I close the session with Putty. The reason for this is that I do not want to keep the computer ON all the time. Is there any way to do this?.  Update with the solution  For my question as it is presented the best solution is use one of the commands provided such as nohup, because you do not have to install any additional software. But if you are in the same problem use screen, install it and use it. It is amazing.  I have selected the answer of Norman Ramsey as favourite because propose several solutions using commands and screen. But please check the other answers specially the one of PEZ, then you get an insight of what screen is able todo. Yes, I'm really sure I want to delete that post Attempting to delete questions on the mobile site on iOS causes two notification messages asking me to confirm the deletion, which it shouldn't do.  I haven't really looked into it, but it may just be that the handlers from full.js and mobile.js are both being triggered, as there seems to be the flash of the error dialog indicating something went wrong on the supposed second AJAX request when the response from the first triggers a page reload.  You can see this happening by following the method calls; the mobile view first calls   StackExchange.question.init() -&gt; StackExchange.question.fullInit()   -&gt; StackExchange.vote.init()     -&gt; u()    ...where u() sets a delegated click handler on  $("div.post-menu *[id^='delete-post-'], table.flagged-posts *[id^='delete-post-']")   ...that calls .preventDefault() on the event, but doesn't block other handlers from firing.  It then later calls StackExchange.mobile.init(), which in turn calls the method J() that sets up a similar handler directly on $(".delete-post").  Since both handlers get triggered, there's two confirmation dialogs, and two attempts to delete the post. The extra handler in mobile.js seems unnecessary, so just removing it would appear to be the easy fix to the problem. Does $\{f_ng_n\}\to fg$ uniformly? Techniques for modeling a network of blood vessels If you've ever seen anything like Body Worlds or the Bodies: The Exhibition you'll know how they dissect individual organ systems and put them on display with a technique known as . For instance, plastic can be pumped through the circulatory system such that when it hardens, acid can be used to dissolve the rest leaving the underlying network of blood vessels underneath.    I'm looking forward to modeling something as intricate as this, but my first attempts have failed. The initial idea was to generate a tree structure with the Sapling Tree add-on. Then I could do a Boolean modifier with my model, and touch up the end points individually by extruding to follow the contours of the model's surface. However, the Boolean modifier fails in this example.  Do I have to code this procedurally with a Python script or is there some other method I should try first? I have a Python script which takes as input a list of integers, which I need to work with four integers at a time.  Unfortunately, I don't have control of the input, or I'd have it passed in as a list of four-element tuples.  Currently, I'm iterating over it this way: for i in range(0, len(ints), 4):     # dummy op for example code     foo += ints[i] * ints[i + 1] + ints[i + 2] * ints[i + 3]  It looks a lot like &quot;C-think&quot;, though, which makes me suspect there's a more pythonic way of dealing with this situation.  The list is discarded after iterating, so it needn't be preserved.  Perhaps something like this would be better? while ints:     foo += ints[0] * ints[1] + ints[2] * ints[3]     ints[0:4] = []  Still doesn't quite &quot;feel&quot; right, though.  :-/ Related question: How to find integer solutions to $M^2=5N^2+2N+1$? Disclaimer: I'm pretty novice at sysadmin stuff.  I'm trying to set up port forwarding in an AWS EC2 instance, this has to be done in the command-line because I don't want to go in and edit anything, it has to be automatic (it's part of a build process).   sudo echo "net.ipv4.ip_forward = 1" &gt;&gt; /etc/sysctl.conf      Permission denied   The weird thing is I've been (successfully) using sudo for pretty much every command that required su privileges. If I do sudo su before the command (trying it out by hand in an ssh session), then it works.  Reasons behind this? Possible solutions that don't involve sudo su or manual edits? Stop iPhone alerting me when I'm in a phone call When I'm in a phone call, I still get alerts for emails and texts. The noise will play and, if the phone is on Speaker, it will vibrate -- often leading the person I'm talking to wonder what that weird noise was.  Surely there must be a way to silence the phone while you're talking on it. It's very distracting to have beepings going off right next to your ear! I'm going to mount my 47" LCD above my fireplace. I'm not looking for arguments against this decision. I'm looking for wiring solutions. The diagram below should help explain the situation.   _________________________________________________ |     |     |    | |   |   |   | |    |     |     | |     |     |    | |   |   |   | |    |     |     | |     |     |    | |   |   |   | |    |     |     | |     |     |    | | p |   | m | |    |     |     | |     |     |    | |   |   |   | |    |     |     | |     |     |    #################    |     |     | |     |     |    ##             ##    |     |     | |     |     |    ##             ##    |     |     | |    P|     |    ##             ##  m |     |P C  | |_____|_____|____##_____________##____|_____|_____|    | = stud # = fireplace brick P = existing power outlet C = existing cable outlet p = new power outlet m = new media outlet   Essentially, there is an existing power outlet on either side of the fireplace and a cable outlet on the far right side of the fireplace. I'm intending to put my non-TV media equipment on the right side of the wall and the television above the fireplace. This means I need two things above the fireplace: power and HDMI. I don't want to just run an HDMI cable in the wall. I'd prefer to have some sort of conduit to simplify replacing the cable or having a second (with one of these on each end: ). I only need to drill through two studs that are 6" apart above the right side of the fireplace in order to access the vertical space where I want the other end. For the power, I need to drill through two 6"-spaced studs above the left-side of the fireplace, but then another 2 full-height studs.  There are a couple of caveats:   This is an externally facing wall, which means there's insulation. I'm assuming this will make things more difficult. I'd like to refrain from cutting more holes in the wall than is necessary for the outlets (to reduce drywall damage/repair).   I've considered a couple of options:   Cut the openings for the outlets above the fireplace, and use a flexible drill bit to drill through the studs above the fireplace. This minimizes dry-wall damage, but how difficult is this with insulation in the wall, how can I feed the conduit through those holes, and how would I drill through the full-height studs on the left for power? Cut a wide section of dry-wall (4" high?) from the desired media outlet to the right until reaching the gap above the desired lower outlet. This results in some dry-wall damage, but would allow more control for drilling holes in the studs and running conduit. This still doesn't solve the problem of getting through the full-height stud for the power. For the power, I would need to extend the cut-out two studs further.   What should I do? Proof of upper-tail inequality for standard normal distribution $X \sim \mathcal{N}(0,1)$, then to show that for $x &gt; 0$, $$ \mathbb{P}(X&gt;x) \leq \frac{\exp(-x^2/2)}{x \sqrt{2 \pi}} \&gt;. $$ Calculating conditional entropy given two random variables I have been reading a bit about conditional entropy, joint entropy, etc but I found this: $H(X|Y,Z)$ which seems to imply the entropy associated to $X$ given $Y$ and $Z$ (although I'm not sure how to describe it). Is it the amount of uncertainty of $X$  given that I know $Y$ and $Z$? Anyway, I'd like to know how to calculate it. I thought this expression means the following:  $$H(X|Y,Z) = -\sum p(x,y,z)log_{2}p(x|y,z)$$  and assuming that $p(x|y,z)$ means $\displaystyle \frac{p(x,y,z)}{p(y)p(z)}$, then  \begin{align} p(x|y,z)&amp;=\displaystyle \frac{p(x,y,z)}{p(x,y)p(z)}\frac{p(x,y)}{p(y)}\\&amp;=\displaystyle \frac{p(x,y,z)}{p(x,y)p(z)}p(x|y) \\&amp;=\displaystyle \frac{p(x,y,z)}{p(x,y)p(x,z)}\frac{p(x,z)}{p(z)}p(x|y)\\&amp;=\displaystyle \frac{p(x,y,z)}{p(x,y)p(x,z)}p(x|z)p(x|y) \end{align} but that doesn't really help.  Basically I wanted to get a nice identity such as $H(X|Y)=H(X,Y)-H(Y)$ for the case of two random variables.  Any help?  Thanks Why do statisticians discourage us from referring to results as "highly significant" when the $p$-value is well below the conventional $\alpha$-level of $0.05$?  Is it really wrong to trust a result that has 99.9% chance of not being a Type I error ($p=0.001$) more than a result that only gives you that chance at 99% ($p=0.01$)? 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) Find the last $2$ digits of $$\large7^{7^{7^{10217}}}$$   So far I have: $17\cdot 601=10217$ and $7=7 \pmod{10}$. Any help greatly appreciated. iOS 7 Locked Bug via Ubuntu 13.10 I wanted to bring up an issue with the latest Ubuntu release that I hope can be solved. Although I will agree with the community that iOS 7 is not the most open platform release, it still is my desire to be able to grab Photos, Music, and Files off my Phone similar to what I would do to any other device.  Every time I connect my device to Ubuntu, I receive the following notification:  The device "Justin's iPhone" is locked. Enter the passcode on the device and click "Try again".   On my iPhone, I select the following   Unfortunately, this is where problems start to arise. It appears that Ubuntu either does not recognize the permissions from my iPhone or the iPhone is not allowing itself to truly be unlocked. As we can see the permissions are   Browsing askubuntu, I encountered the following   After running the code, I receive the following error:  justin@justin-CT15:~$ idevicepair unpair &amp;&amp; idevicepair pairERROR: Device d1fea2c56e51199f901eb34020a1581ea31a2a50 is not paired with this host   If I call the command again, i receive another error:  justin@justin-CT15:~$ idevicepair pair ERROR: Could not pair with the device because a passcode is set. Please enter the passcode on the device and retry.   Ultimately, I am stuck to experiment with solutions that end up not working. I am troubled by the lack of information and support for the iOS 7 platform on Ubuntu's latest release. If anyone has a workable solution or experiment for a workaround, I am happy to try  Thanks for reading and have a wonderful day! Fspy add-on not installing How to find correctly the .bib file?