I know on linux when you use sudo, it wants a password.  Things I have already tried:  if i type sudo apt-get install g++ and hit enter, the cursor goes to the next line and no output happens. I thought the issue might have been apt-get, so i tried that without sudo, and got the error saying i might not be root. so that is working.  i tried typing sudo, hit enter, cursor goes down to the next line and nothing.  i can type in my password and it isn't ecnrypted. how do i fix this?
When I'm about to install a program in the terminal it wants the password:  [sudo] password for xxx:   But when I start to type my password nothing happens. What should I do?
How do constant aperture zoom lenses work? Cheaper zoom lenses usually are faster at the wide end and slower at the long end (for example, the $150 Canon EF-S 18-55mm f/3.5-5.6). More expensive constant-aperture zoom lenses have the same aperture regardless (for example, $800 Canon EF 17-40mm f/4.0 L).  My question is: are these good lenses  at the wider settings, or do they have a different optic system that allows them to maintain the same aperture throughout the zoom range? Is there an upper limit to temperature in thermodynamics or statistical mechanics In many presentations of statistical mechanics where we have a system of particles having mass, such as the molecules of an ideal gas, the temperature is often equated to the average relative velocity of the particles. However no such velocity can exceed that of light. Is there therefore an absolute upper bound to temperature as well as an absolute zero? What's the easiest way to set up a LAMP stack? Where can I get the original Unix? After an AJAX request, sometimes my application may return an empty object, like:  var a = {};   How can I check whether that's the case? is looking bad right now. No errors in the console, but the following files have no content:         The CSS on another subdomain works fine though: How to discard unsaved changes to a view when editing it leads to a WSOD? \leqslant causes "Undefined control sequence" I have the following line: $0 \leqslant b \leqslant 1$  I want to display 0 &lt;= b &lt;= 1, but I get Undefined control sequence  thanks Drush CC all returning "No Drupal site found, only 'drush' cache was cleared" I've tried other solutions, but none of them are specific to my setup. I just started using the new Linux subsystem featured in the recent Windows 10 update. I'm using WAMP x64 v3.0.6, and have successfully cloned my website and got it up and running. At the root of the Linux subsystem, I installed Drush globally with Composer, using the directions given on the .  Typing drush status returns the following when I run it in my default directory:  Drupal version         :  7.50  Site URI               :  http://default  Database driver        :  mysql  Database hostname      :  localhost  Database port          :  Database username      :  root  Database name          :  aerosphere  PHP executable         :  /usr/bin/php  PHP configuration      :  /etc/php5/cli/php.ini  PHP OS                 :  Linux  Drush script           :  /home/bob/.composer/vendor/drush/drush/drush.php  Drush version          :  7.1.0  Drush temp directory   :  /tmp  Drush configuration    :  Drush alias files      :  Drupal root            :  /mnt/c/wamp64/www/drupal-7.50  Site path              :  sites/default   But, as mentioned in the title, drush cc all returns No Drupal site found, only 'drush' cache was cleared.[warning] I assume it has something to do with adding a path to the .bashrc, but I don't know what to add. Any tips would be greatly appreciated!  My question is different from "", they're on a Mac and using MAMP, and I'm using WAMP on Windows. I've tried the solutions offered on that post, but the issue has not been resolved.  I'm obviously having issues connecting to MySQL as I get this when I run mysql command:     The program 'mysql' can be found in the following packages: * mysql-client-core-5.5 * mariadb-client-core-5.5 * mysql-client-core-5.6 * percona-xtradb-cluster-client-5.5      Try: sudo apt-get install .   So I've added these lines to my .bashrc file:  PATH="$HOME/.composer/vendor/bin:$PATH" export PATH="/mnt/c/wamp64/mysql/mysql5.7.14/bin:$PATH"   The top line was added to get drush working. I've checked multiple times, and I have the path correctly set, but it's still not working. Let $f$ be a continuous function. If $f$ is uniformly continuous then it maps cauhy sequence into cauchy sequence. Is the converse true? That is if $f$ maps cauchy into cauchy gives the uniform continuity of $f$. I think it's no. Can suggest a counter example Schedule to open website I'd like to open a website at regular intervals per day, i.e., the browser should open and automatically navigate towards a pre-set URL.  I looked at options like scheduling to open browser, but I can't figure out how to open it with a default URL. (No I do not want to make this my start page)  Any help is appreciated Does a correlation matrix of two variables always have the same eigenvectors? I perform Principal Component Analysis using two variables that are standardized. This is done by applying a SVD on the correlation matrix of the concerned variates. However, the SVD gives me the same eigenvector (weights) irrespective of what the two variables are. It's always [.70710678, .70710678]. I find this strange. Of course, the eigenvalues differ.  My question is: How to interpret this?    PS. I wanted to conduct a total least squares regression on two variables. My statistical programme does not provide TLS, but TLS luckily equals Principal Component Analysis, as far as I know. Hence my question. The question is not about TLS directly, but why I get the same eigenvectors irrespective of which variables I use (as long as they are exactly 2). Partition 256 GB SSD for dual Boot, Windows 10 + Ubuntu 19.04 I plan on installing Ubuntu 19.04 and give it 100 GB of my 256 GB SSD space and leave the rest for Windows as I would primarily be using Ubuntu.     A. Now, as I plan to install a lot of applications in Ubuntu, should I give more space to the / partition than the home partition? (Or maybe even drop the /home altogether?).    B. I have another 128 GB SD card for files like photos, audio and video files. Please suggest me the optimal partitioning for the use case.    C. Also, I have 8 GB of RAM so what should be the optimal swap partition size?    D. How would the distribution be if I choose "install Ubuntu alongside Windows" option? Isomorphism of centers of isomorphic groups Ubuntu 14.04 multi touch screen support Just installed 14.04. It seems to be converting all my screen touch gestures to mouse gestures. And it only supports one point touch. It is supposed to support ten touch points (tested with windows 8.1).  Am I missing something here? Do I have to install some kind of package? Or is it just not supported?  Test - being able to draw here: Windows does not mount USB NTFS superfloppy I have a Transcend Storejet external USB hard disk. This is not an SSD, but a mechanical disk with rotating plates. I have formatted the whole disk, without partitioning, as NTFS. I have used mkntfs tool under Linux.  When plugged into a Linux machine, the system sees a drive with two partitions (/dev/sdc /dev/sdc1 /dev/sdc2). However, as I know it is a partitionless disk, I can mount the whole device (mount -t ntfs /dev/sdc /mnt) and it works without any problems.  When plugged into a MS Windows XP machine, the systems sees a disk with two unformatted partitions, and it does not assign a drive letter to either the whole disk, nor to any of the partitions.  Would anyone know how to get MS Windows to mount my disk as a NTFS superfloppy?  I have already tried removing old USB mounting points and residual devices using 'DriveCleanup'. It did not help.  By the way, I also have an external Kingston USB SSD, also formatted as NTFS superfloppy, without partitioning. However, this one is recognized and mounted normally by MS Windows. What are the different ways that a message can be displayed to a bash shell after a user logs in? I was reading a  where the author mentions: "The coefficient of variation is primarily a descriptive statistic, but it is amenable to statistical inferences such as null hypothesis testing or confidence intervals. Standard procedures are often very dependent of the normality assumption and current work is exploring alternative procedures which are less dependent on this normality assumption."  The paper is from 2010. So my question is: has there been any recent "advancements" in terms of a coefficient of variation statistic that is not dependent upon the normality assumption? And, is this what one may call a non-parametric CV? Currently selected indicator's colour in flag summary and help pages, can be the same as the site's colour code Star vs Heart icon to represent save as a favourite I am working on a mobile app that involves the user saving a favourite location. I wanted to use an icon to represent that feature, but I'm not sure which one is better – a star or a heart icon.  Some say heart icon tends to increase the rate of productivity, and some say they are used to a star icon to 'save' or 'bookmark' something.  What do go you guys think?