What is the lastest level of ubuntu for a Dell Optiplex 620 computer
How do I find out which version and derivative of Ubuntu is right for my hardware in terms of minimal system requirements?
Opposite of "straight talk" How to analyse 'Element not Found' exceptions when working with Selenium Grant permission for new created files inside folder automatically I have a folder which permission is set to 777 but when I add any files or folder unziping in that folder. Extracted files or folder permission never change. Destination folder permission is 777 and I want what I will add in that folder will automatically get permission of 777.   When I add any files or folder by extracting .zip in that folder, extracted folder/files permission won't change automatically. I always have to chmod for newly add file/folder! List all directories that do NOT have a file with a given file name inside How would I go into listing all directories that do not have a file with a given file name inside? e.g. given this tree  /   /a      README      file001      file002   /b      README      file001   /c      file003   I want to list the directories that do not have a file named README, in this case it would be directory /c. How would I do that? I can't think of any syntax using e.g. find. How to address a professor in letter? Is there no electric field inside a conductor? I came across this statement while studying electric currents and I am confused:  "There is no electric field inside a conductor. Hence no current can flow through it".  Is there a fallacy in this statement?  Any help would be appreciated.  The conductor being discussed is ideal. What is the driving force for the current in this case? I am interested in setting up a Ruby on Rails environment on my 10.10 laptop.   Is there anything special I need to keep in mind for installation (i.e. that could be new or unique to 10.10)?   Are there any suggested walkthroughs that I could follow along with?  Thanks in advance. Right at the beginning of the game, Meowth comes into your room and attempts to wake you up. At this point, I assume I have to press some button to get out of bed, but the D-Pad or A button doesn't do anything, nor any of the other buttons. How do I get out of bed to start the game? I used osm2pgsql to import data into my PostgreSQL database and it put gave me the following 4 tables, planet_osm_point, planet_osm_line, planet_osm_polygon and planet_osm_roads.   I have looked at the schema for osm2pgsql and inside the planet_osm_point table there is a column 'way' of type point. I tried to query it as an array like it says in the documentation here ():     It is possible to access the two component numbers of a point as   though the point were an array with indexes 0 and 1. For example, if   t.p is a point column then SELECT p[0] FROM t retrieves the X   coordinate and UPDATE t SET p[1] = ... changes the Y coordinate. In   the same way, a value of type box or lseg can be treated as an array   of two point values.   Anyone know the correct query the planet_osm tables from osm2pgsql based on long/lat? For example if I wanted to retrieve the information for Big Ben (London) I would query along the lines of:      SELECT * FROM planet_osm_point      WHERE ST_Y(ST_Transform(way, 4326)) = '-0.12'        AND ST_X(ST_Transform(way, 4326)) = '51.5';   There is no error message, it comes out with the table names, but no data is output either. (Its an empty table). What am I doing wrong here?  Perhaps it is too precise, i.e. there are no coordinates that match it exactly? Perhaps I need to try being more general, say 51 &lt; long &lt; 52 and -0.5 &lt; lat &lt; 0. Although this would throw back multiple results so would not be quite as accurate. How to list all files ordered by size I would like to list all files in the order of big to small in size and the files could be present anywhere in a certain folder. I have what is probably a simple question, but it is baffling me right now, so I am hoping you can help me out.  I have a least squares regression model, with one independent variable and one dependent variable. The relationship is not significant. Now I add a second independent variable. Now the relationship between the first independent variable and the dependent variable becomes significant.  How does this work? This is probably demonstrating some issue with my understanding, but to me, but I do not see how adding this second independent variable can make the first significant. Is it possible to use a primitive type (int) in as a generic type in Java? Specifically, with a SortedMap&lt;Vector&lt;String&gt;, int&gt; I get "dimensions expected after this (int) token." Help! I recently switched from Windows to Mac. Steam says I have fewer Mac specific games than total games and it should be an equal amount unless you can only download, install, and play once from your account. I thought I bought it so that it would work across all operating systems. If this is true, is there a work around or a discount for re-purchasing for the other OSes? What governor limits impact Apex Describe methods? Are there any governor limits, or considerations that I should be aware of when using Apex Describe methods?  So for example, the author of this blog post uses the structure below to get the record type instead of doing a soql query.     //Generate a map of tokens for the sObjects in your organization Map gd = Schema.getGlobalDescribe();  //Retrieve the describe result for the desired object DescribeSObjectResult result = gd.get('Account').getDescribe();  //Generate a map of tokens for all the Record Types for the desired object Map recordTypeInfo = result.getRecordTypeInfosByName(); system.debug('RECORD TYPES:' + recordTypeInfo);  //Retrieve the record type id by name String recordTypeId = recordTypeInfo.get('RECORDTYPE_NAME').getRecordTypeId(); Proof of $A\cap(B\cup C) = (A\cap B)\cup(A\cap C)$ Redirect Restricted Page to 404 Is there a way to show a 404 page if the current logged in user does not have the right clearance to view the page? I am looking for a PHP method, something like  if( !current_user_can('administrator') ) { show_404(); exit(); }   I have thought about using a redirect, but I would like to keep the url the same. Where did folder "merge" or "keep both" go in OS X 10.9 Mavericks? Before Mavericks one could hold the ALT key and move a folder "A" onto a folder "B" where already an "A" existed. In this case Mac OS X asked in Lion if I want to merge - or on Mountain Lion if I want to keep both (which was also a merge).  I can't find this option in Mavericks.  Did Apple remove this useful feature?  Any hints?  (And yes: I own ForkLift, which can do it - I just sometimes still prefer the Finder). Everyone is aware of Dijkstra's  (also  .html transcript and  .pdf) and there has been a formidable push since that time to eschew the goto statement whenever possible. While it's possible to use goto to produce unmaintainable, sprawling code, it nevertheless remains in . Even the advanced  control structure in Scheme can be described as a sophisticated goto.  What circumstances warrant the use of goto? When is it best to avoid?  As a followup question: C provides a pair of functions, setjmp and longjmp, that provide the ability to goto not just within the current stack frame but within any of the calling frames. Should these be considered as dangerous as goto? More dangerous?    Dijkstra himself regretted that title, for which he was not responsible. At the end of  (also  .pdf) he wrote:     Finally a short story for the record.   In 1968, the Communications of the ACM   published a text of mine under the   title "The goto statement considered   harmful", which in later years would   be most frequently referenced,   regrettably, however, often by authors   who had seen no more of it than its   title, which became a cornerstone of   my fame by becoming a template: we   would see all sorts of articles under   the title "X considered harmful" for   almost any X, including one titled   "Dijkstra considered harmful". But   what had happened? I had submitted a   paper under the title "A case against   the goto statement", which, in order   to speed up its publication, the   editor had changed into a "letter to   the Editor", and in the process he had   given it a new title of his own   invention! The editor was Niklaus   Wirth.   A well thought out classic paper about this topic, to be matched to that of Dijkstra, is , by Donald E. Knuth. Reading both helps to reestablish context and a non-dogmatic understanding of the subject. In this paper, Dijkstra's opinion on this case is reported and is even more strong:     Donald E. Knuth: I believe that by presenting such a   view I am not in fact disagreeing   sharply with Dijkstra's ideas, since   he recently wrote the following:   "Please don't fall into the trap of   believing that I am terribly   dogmatical about [the go to   statement]. I have the uncomfortable   feeling that others are making a   religion out of it, as if the   conceptual problems of programming   could be solved by a single trick, by   a simple form of coding discipline!" After Upgrade to Ubuntu 20.04: "Oh no! Something went wrong" COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better?