I have downloaded ubuntu-18.04-desktop-amd64.iso and would like to run from cd without destroying my existing Windows System.  I burned the iso file to a dvd. What do I do next? What do I do with this iso file?
I'm a little confused as to whether I should install Ubuntu on its own partition on my hard drive, use VirtualBox or another virtualization package to install it, or use Wubi to install it directly on top of my current OS (Win 7). I definitely want to learn and use Ubuntu, so this is not just for playing around with it.   Also, if I choose to partition, should I partition the hard drive myself or should I let the Ubuntu installation menu do it for me? I understand that I am going to need a main partition, for Ubuntu's core components, and also a swap partition. Then there is the option to add a partition for "home"- I don't understand what combination of these partitioning options I should choose, or whether it is better to partition in Windows before I install Ubuntu or just partition my hard drive when I install Ubuntu itself
cd to previous directory without echo of directory name This  gave me cd - as shorthand to change to my previous directory in Bash. It does have a major problem: it prints the directory it changes to, wasting my screen space, as that directory is then repeated in the prompt on the next line.  I know I can do cd $OLDPWD, also mentioned in that answer, and cd - &gt;/dev/null but that is much more typing.   In the bash man page it says:     ... or if - is the first argument, and the directory change is successful, the absolute path name of the  new  working  directory  is written to the standard output.   How can I make - not to be the first argument? By using any of the cd optional arguments? Any other way to suppress the echo or minimise typing without the need for defining functions/aliases on every machine I work with? Is there a difference between SWAP and Cache memory? I installed the indicator-multiload 0.2-0ubuntu1 from the software center. (It's very similar to the gnome panel indicator showing memory and CPU graphs)  When I click on the Unity panel which shows the little memory graph, it says ;  Mem :1.451 GB   Cache: 2.581.  This is also represented in the color graph.  However, when I load the System Monitor, SWAP is at a flat 0.  Is this normal, or could there be a bug in either the System Monitor or Panel Indicator? Today I was informed by VFS that my tourist visa for UAE got approved. I'm travelling to UAE on 16th December 2014 and returning on 7th Jan 2015. But when I checked the "valid until" date on the visa it states 30 December 2014.    Does this date mean I should return before December 30th? Should I get it corrected from VFS? "Baggage" versus "luggage" Is there a quick way to set an HTML text input (&lt;input type=text /&gt;) to only allow numeric keystrokes (plus '.')? How to get week number in Python? Error on Ubuntu boot up - "recovering journal" Trying to figure out what this means:    I got into the GRUB menu, chose Advanced Options, boot in recovery mode, login as root, and I did:  root@xps:~# sudo fsck -f / fsck from util-linux 2.27.1 e2fsck 1.42.13 (17-May-2015) /dev/nvme0n1p2 is mounted. e2fsck: Cannot continue, aborting.   Coincidentally, I am also seeing this fuzzy rainbow thing on the outside of desktop windows:    But now the machine won't even boot up at all. Can internal forces do work? My Mechanics textbook claims that the sum of the work by internal forces is not generally zero.  translated to English the paragraph reads:     Notice about the work by internal forces: the work by the internal forces is in general not equal to zero although the sum of the internal forces is always equal to zero. Since the work also depends on the relative displacement of the two pointmasses in the material system, the work provided by these 2 internal forces will generally not be equal to zero.   Other sources claim that the work done by internal forces is always zero.  (answer by Mark Eichenlaub)     Then I didn't do any work on the system at all since, by definition, only external forces can do work.        the net work done by internal forces is zero since they do not cause motion of the object.   To me it would seem that these sources contradict eachother. Do they? If so, which one is correct? If not, please explain why they don't contradict eachother. What is the difference between the examples below?  Generally, in a newspaper, news is based on past tense (things which have already happened).   Then why are headlines written in ways that says: He Kills (shouldn't it be: He Killed)?  For example:  Parliament passes bill vs. Parliament passed bill  Also  He kills his friend vs. He killed his friend  Please help. What is the relationship between Guide Number and flash power level? From this , I understand that the flash guide number (GN) is given by the following formula:  Guide Number = Shooting Distance × f-number ÷ ISO factor   I'm assuming that the GN calculated via the equation above will be based on a flash that is firing at full power. Am I correct to assume that if I set the flash to fire at half power, that the guide number is effectively halved? i.e. the equation will now be:  Guide Number = Shooting Distance × f-number ÷ ISO factor * Power Level   where power level can be the following 1, 1/2, 1/4, 1/8, ... 1/64, etc? How to prove this sequent using natural deduction? How to upgrade to MySQL 8.0? I have a Drupal site 8.6.10 on an Ubuntu server 18.04 with MySQL 5.7.25  I want to update MySQL to version 8.0  Here are the steps I followed :   I backed up my database. I uninstalled MySQL from my server with the commands :  $ sudo systemctl stop mysql $ sudo apt remove mysql-* $ sudo apt purge mysql-* $ sudo apt autoremove $ sudo dpkg -l | grep mysql | grep ii  I added the repository with the command :  $ wget https://repo.mysql.com//mysql-apt-config_0.8.12-1_all.deb  I installed the package with the command :  $ sudo dpkg -i mysql-apt-config_0.8.12-1_all.deb            My problem :   I install MySQL with the command :  $ sudo apt update $ sudo apt install mysql-server    When I do step 5, it installs MySQL 5.7 why does not it install version 8 ? Prove that $\gcd(a^n - 1, a^m - 1) = a^{\gcd(n, m)} - 1$ For all $a, m, n \in \mathbb{Z}^+$,   $$\gcd(a^n - 1, a^m - 1) = a^{\gcd(n, m)} - 1$$ I'm looking into developing an ordering app for a potential client. The main part that I'm concerned about in this question is the payment mechanism. I would assume that there are already multiple plugins or similar programs out there, but I'm not sure where (or if) I should be asking for recommendations. Share menu hangs iOS app The Share menu in iOS 13 got a redesign, and the Stack Exchange iOS app is no longer compatible with it. I can still use it to copy the link, but when I try close the menu, it remains stuck. Opening another app and then returning automatically dismisses the menu, but then I can't use the back button anymore to return to the question list. (I'm still able to refresh the page, so it's a navigation issue.)    Ironically, I discovered this bug while trying to mark  as a duplicate; in the app, the quickest way to do that is to use the Share menu to copy the link to the original question to the clipboard...   App Version: 1.6.6.2 Device: iPhone 7 Plus OS Version: Version 13.1 (Build 17A844) I want to draw a perfect rectangle. How can I do that with QGIS v.3+?  .  Is there a similar solution for the latest QGIS version? Local collection of Python packages: best way to import them? Qualcomm Atheros AR9462 with Ubuntu 18.10 I can't enable the Wifi (nothing happens when press enable button) and in Wifi settings it says:     "No Wi-Fi Adapter Found"   I have tried several things from other questions/answers here but nothing worked. Here some information if this is helpful for the answer:     Device: Lenovo Miix 2 11   sudo lspci:  Network controller: Qualcomm Atheros AR9462 Wireless Network Adapter (rev 01)   sudo lshw -C network:  *-network DISABLED            description: Wireless interface    product: AR9462 Wireless Network Adapter    vendor: Qualcomm Atheros    physical id: 0    bus info: pci@0000:02:00.0    logical name: wlp2s0    version: 01    serial: 48:d2:24:8a:ea:e6    width: 64 bits    clock: 33MHz    capabilities: pm msi pciexpress bus_master cap_list rom ethernet physical wireless    configuration: broadcast=yes driver=ath9k driverversion=4.18.0-16-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11    resources: irq:18 memory:f0400000-f047ffff memory:f0480000-f048ffff   sudo lsmod | grep ath:  ath3k                  20480  0 bluetooth             548864  12 btrtl,btintel,btbcm,bnep,ath3k,btusb ath9k                 151552  0 ath9k_common           36864  1 ath9k ath9k_hw              475136  2 ath9k_common,ath9k ath                    36864  3 ath9k_common,ath9k,ath9k_hw mac80211              794624  1 ath9k cfg80211              663552  5 wl,ath9k_common,ath9k,ath,mac80211   In system settings it shows the Wifi-Adapter Name:  Qualcomm Atheros AR9462   Edit:  lspci -knn | grep Net -A3; rfkill list:  02:00.0 Network controller [0280]: Qualcomm Atheros AR9462 Wireless Network Adapter [168c:0034] (rev 01) Subsystem: Lenovo AR9462 Wireless Network Adapter [17aa:3214] Kernel driver in use: ath9k Kernel modules: ath9k, wl 0: phy0: Wireless LAN     Soft blocked: no     Hard blocked: no 1: ideapad_wlan: Wireless LAN     Soft blocked: no     Hard blocked: yes 2: ideapad_bluetooth: Bluetooth     Soft blocked: yes     Hard blocked: yes I need to get UTF-8 working in my Java webapp (servlets + JSP, no framework used) to support äöå etc. for regular Finnish text and Cyrillic alphabets like ЦжФ for special cases.  My setup is the following:   Development environment: Windows XP Production environment: Debian   Database used: MySQL 5.x  Users mainly use Firefox2 but also Opera 9.x, FF3, IE7 and Google Chrome are used to access the site.  How to achieve this? Get the name of an object's type