Any download command is terminated with this error - "Errors were encountered while processing: linux-image-4.15.0-20-generic"
/usr/sbin/grub-mkconfig: 1: /etc/default/grub: If: not found
zsh scripting - How do I NOT match a pattern in filename generation? Can I prevent others from editing my question? edited my question,  where I specifically said that our software sending back stacktrace to one of our servers was a user-known public feature.  He then modified the title of my post, along with the entire content, making it sound like I snuck in the feature and that our application was phoning home without our users knowing.    I specifically wrote in the original post that the feature was not sneaky. He completely changed the meaning of my post. I find this to be rather unacceptable.  A few questions:   Is it possible to prevent editing of my posts? How can I retaliate? Can I file a complaint?   Can people with  do anything they want on Stack Overflow? Paging Lucene's search results I am using Lucene to show search results in a web application.I am also custom paging for showing the same. Search results could vary from 5000 to 10000 or more. Can someone please tell me the best strategy for paging and caching the search results? Copying and pasting features using PyQGIS I have created a table join between two shapefiles which I've named 'OSMM' and 'Mastermap'. I want to copy and paste all features (polygons) without a match from the target layer ('Mastermap') into the parent shapefile ('OSMM'). I can't find any up-to-update code for QGIS 3.6. Here is my code so far: #1. loads the SHP files uri = 'C:/Users/xx/Downloads/OSMM.shp' vlayer = iface.addVectorLayer(uri,&quot;&quot;,&quot;ogr&quot;) uri = 'C:/Users/xx/Downloads/Mastermap.shp' vlayer = iface.addVectorLayer(uri,&quot;&quot;,&quot;ogr&quot;)  #2. Joins &quot;InvoiceNum&quot; from OSMM to Mastermap layerToJoin = QgsProject().instance().mapLayersByName('OSMM')[0] target = QgsProject().instance().mapLayersByName('Mastermap')[0] myJoin = QgsVectorLayerJoinInfo() myJoin.setJoinFieldName('InvoiceNum') myJoin.setTargetFieldName('InvoiceNum') myJoin.setJoinLayerId(layerToJoin.id()) myJoin.setUsingMemoryCache(True) myJoin.setJoinLayer(layerToJoin) myJoin.setJoinFieldNamesSubset(['InvoiceNum']) target.addJoin(myJoin)  #3. Selects NULL features from Mastermap params = { 'EXPRESSION' : '\&quot;OSMM_InvoiceNum\&quot; is NULL', 'INPUT' : 'C:/Users/xx/Downloads/Mastermap.shp', 'METHOD' : 0 } processing.run(&quot;qgis:selectbyexpression&quot;, params)  So how do I perform the PyQGIS version of Ctrl+C on 'Mastermap' and Ctrl+V into 'OSMM'? Presumably I will then need to use the following code: #5. Save the changes OSMM.commitChanges() Why do fonts look messed up in Adobe Acrobat? Display each sub-directory size in a list format using one line command in Bash? I want to get a list of the directories and their sizes in a list format like how you get when you do a ls -l.  The thing is that is there a one line command that can do this? I see others have long commands just to output this. That's just too long.  What command can do this or combination of commands that can be easily typed? du -h gives it, but it displays all of the sub-folders which is not what I want. just the current directories folders. Add AD users to sudo group not working | CentOS 6.7 Regular expression to match non-ASCII characters? What is the easiest way to match non-ASCII characters in a regex? I would like to match all words individually in an input string, but the language may not be English, so I will need to match things like ü, ö, ß, and ñ. Also, this is in Javascript/jQuery, so any solution will need to apply to that. Someone who gives unsolicited explanations in a condescending way How can I pause a render in progress and then resume it at a later time? Asymptotics of uniformly continuous functions over $\mathbb R$ Can "real" be used as an adverb to describe an adjective? Is LAN with StarCraft 2 definitely not possible? I'd like to be able to easily transfer large files wirelessly, fast, between Android devices - preferably without requiring root.  As a secondary objetive, it wouldn't hurt if the same solution could be used, to transfer files between the Android devices and a Windows PC.   Specifically, I'm trying to exchange files between my Nexus 7 (Android 4.2.2) and Samsung Galaxy S2 (Android 4.0.4).   Bluetooth is simply too slow, so that's out of the question Transfer via the Internet is also not an option, hence so is cloud-based solutions Only Nexus 7 supports NFC, so that's out too  looked promising and very simple, but does not work on "Devices that don't have WiFi Tethering setting, such as the Nexus 7"   Wi-Fi direct ( and up) seems to be a decent lowest common denominator between my two devices, however...  Galaxys S2's native Send via Wi-Fi Direct sees the Nexus, but seems to get stuck in the "Connecting..." most times. When there finally seems to be breakthrough, I get "Waiting..." and a spinning circle. Even if it worked, it would only allow me to send from the Galaxy S2 to the Nexus 7, as a similar option os not present on the Nexus 7.  J4velin's  is no longer available in the Play Store, with the following explanation:     WiFi Direct drivers are broken on many devices, which led to users leaving negative reviews for this app. As I don't see any sense in keeping a free app published when only getting 1-star-ratings (for an issue which only your device manufacturer can fix), the app is no longer available at the Play Store.   Nick Adams'  seems flaky at best. Invations from Nexus 7 to Galaxy S2 are never received. Invitations from Galaxy S2 are mostly received, but even when accepting promptly, the peers doesn't always show as connected. When they finally do, usually after quite a long wait, I can select a file to send but it's never transferred -  "Transfer failed" it says almost immediately in the notification bar.  budius inc's  is working slightly better, but still very unreliable. I actually managed to (occasionally) send files both ways, but never when attempting connection from the Nexus 7. To send from the Nexus 7 to the Galaxy S2, I had to go through this akward manoeuvre:   Share the file on the Nexus 7 via the WiFi Shoot intent Start the Receive WiFi Shoot app on the Galaxy S2 Invite the Nexus 7 from the Galaxy S2 (never the other way around!) Accept the invitation on the Nexus 7 Press the Shoot button on the Galaxy S2   Take the whole switching back and forth between devices, and garnish with random delays or failures in any step of the process...  Is there really no easy, reliable, fast way to transfer files directly between different Android devices?  Generally, my experience with Wi-Fi Direct is all but positive...   A device often won't even see a device lying next to it Sometimes, it will see the other device, only to have it disappear from the list, before I have the chance to connect When I do have a chance, invations are not realiably received (from Galaxy S2 to Nexus 7 mostly reliable, but never worked the other way around) When invitations are received (and accepted), a partnership rarely manages to be setup ("invited" or "connecting") And even when that happens, some apps can't seem to transfer files through it...   *Sigh*  Maybe J4velin's explanation pretty much sums up the sad state of Wi-Fi Direct on Android, which otherwise seemed as the best solution to my quest? Combining two expressions (Expression>) Installing .pkg with terminal ? Is it possible to install a .pkg using a terminal ? (I wanted to install an app through ssh). Difference of the floor of a product and the product of floors Is there any way the following can be simplified?  $$\lfloor f(x)\cdot g(x) \rfloor - \lfloor f(x) \rfloor  \cdot \lfloor g(x) \rfloor$$ Is there an easy way to log all commands executed, including command line arguments? I am trying to find how to log a specific instantiation of rrdtool to see whether the path it is receiving is incorrect.  I know I could wrap the executable in a shell script that would log the parameters, but I was wondering if there was a more kernel-specific way to monitor for that, perhaps a filesystem callback that sees when a particular /proc/pid/exe matches a given binary? Conjugacy Class in a matrix group with columns of standard basis I want to find the conjugacy classes of this group: $$G=\{(a_1,a_2,a_3):a_i=\pm e_j\}\subset GL_3(\mathbb C)$$ I know that $S_3$ is one of the subgroups of this group, so I can check which elements of $S_3$ continues to be conjugate in our group, I know that in $Z(G)$ there is two elements $I,-I$. I know that I have to check the diagonal matrices on which ones are conjugate, but I don't know how to finish and find the others conjugacy class of this group, and I don't Know how to find the number of the elements of the conjugacy class. I'll be thankful for help (Reference : Fraleigh, A first course in abstract algebra)     Prove that a nonempty set $G$, together with an associative binary operation * on $G$ such that $a*x=b$ and $y*a=b$ have solutions in G, $\forall a,b\in G$, is a group.   Because * is an associatie operation, we have to prove that: there exists $e\in G$ such that $e*a=a=a*e$ for any $a\in G$, and that for any $a\in G$ there exists $\alpha \in G$ such that $a*\alpha=e=\alpha *a$.  This is very confusing, first I tried to prove the identity exists. If we consider a=b, then $a*x=a=y*a$, and because of the hypothesis $x,y\in G$ always exists, now we have to show that $x=y$, but I just can't do this with out inverses, so I tried to prove that the inverses exists, however I have no idea how the identity looks like, I'm stuck.  And I tried to get unstuck, so I thought particular cases, first if $G$ had only one element, then what would happend if it had just two elements... but I remembered that we don't know if G is finite or not, and I think this makes things a little bit more complicated.  What can I do?