I'm using GNOME.  In Windows, you can right-click on applications in the taskbar to see your most recently used files, and files you've chosen to stay in the dock. This is one of my most missed features since switching  Here's an example:    Is there a way to have this feature in Ubuntu?
In windows we have an option to view recently opened media files as my recent documents, I was  wondering does there exists something like that in Ubuntu?  via terminal or via GUI?
How to create SQL like composite key I have an object in which there are two fields i.e Phone no. &amp; email. The combination of these fields should be unique Right now I can create just one unique field But I want their composite to work like a unique field.   I know that I can create composite key in SQL but I dont know how to achieve this in salesforce. I read that     A typical stream cipher encrypts plaintext one byte at a time, although a stream cipher may be designed to operate on one bit at a time or on units larger than a byte at a time.   (Source: , William Stallings.)  A block cipher encrypts one block at a time. The block may be of size one byte or more or less. That means we can also encrypt a block of one byte by help of a stream cipher as a stream.  So, what exactly is the difference between a stream cipher and a block cipher? Forced to Quit PhD although the hard and proved work Many introductory quantum mechanics textbooks include simple exercises on computing the de Broglie wavelength of macroscopic objects, often contrasting the results with that of a proton, etc.  For instance, this example, taken from a textbook:     Calculate the de Broglie wavelength for      (a) a proton of kinetic energy 70 MeV      (b) a 100 g bullet moving at 900 m/s   The pedagogical motivation behind these questions is obvious: when the de Broglie wavelength is small compared to the size of an object, the wave behaviour of the object is undetectable.  But what is the validity of the actual approach of applying the formula naively? Of course, a 100g bullet is not a fundamental object of 100g but a lattice of some $10^{23}$ atoms bound by the electromagnetic force. But is the naive answer close to the actual one (i.e. within an order of magnitude or two)? How does one even calculate the de Broglie wavelength for a many body system accurately? How do I identify an airport’s official free Wi-Fi network? While traveling in the Berlin Tegel airport (TXL), I wanted to get on Wi-Fi. I found three unsecured networks in addition to a number of password-protected networks.   _Free_TXL_WiFi airberlin Berlin Tegel Airport WiFi   I had no idea which of these were an official Wi-Fi network provided by the airport and which were provided by other people, potentially for malicious purposes like capturing my network traffic. Presumably the official one uses a captive portal to allow internet access.  Is there any way to determine which Wi-Fi network is the official one provided by the airport? Would airport staff such as at the ticketing booths know? Are there official lists available somewhere?  I’d like an answer that is applicable to airports generally, rather than specific to the Berlin Airport. Also, please don’t just give a blanket “don’t use any public Wi-Fi network” answer; I know there are risks associated with it, but sometimes it is a necessity and so I want to know how to identify the airport-provided one.   suggests there are no official Wi-Fi networks, but the answers are six years old, so it’s not clear if things have changed or if none of the networks I saw were official. Alternatively, why does the force created by blowing out air feel so much stronger than the force created by sucking in air?  Ok, so forget the human factor involved in blowing out candles. Consider a vacuum cleaner with a suction end and a blower end. Anyone who has tried it out notices the blower end creates a much stronger force than the suction end, despite the discharge being (more or less) equal at both ends.  Why does this happen? Providing command key-value arguments with commas in value When using commands that allow using key-value pairs, how can one provide an argument value that has commas in it? As an example, say I'm using the \newacronym command from the glossaries package as below:  \newacronym[firstplural = Alphas, Bravos, and Charlies (ABCs), plural = ABCs]{ABC}{ABC}{Alpha, Bravo, Charlie}   Unfortunately, the comma is used to separate key-value pairs so the Bravos, and Charlies (ABCs) portion doesn't get parsed correctly. Is there a way to overcome this? Solve $\frac{d}{dx}f(x)=f(x-1)$ I am trying to find a function such that   $\dfrac{d}{dx}f(x)=f(x-1)$   Is there such function other than $0$ ? Open CSV File with Different Delimiter I'm going to guess that the answer is "no" based on the below error message (and ), but is there anyway to perform a cross-database query using PostgreSQL?  databaseA=# select * from databaseB.public.someTableName; ERROR:  cross-database references are not implemented:  "databaseB.public.someTableName"   I'm working with some data that is partitioned across two databases although data is really shared between the two (userid columns in one database come from the users table in the other database). I have no idea why these are two separate databases instead of schema, but c'est la vie... A white number inside a black circle. How to make a white number inside a black circle (the picture below)? I want to change numbers inside the black circle, of course.  I use Share LaTeX. I have read some articles here but anyone are not what I would like to get. I would like to get this  (the picture below) - the sixth answer.   Thanks for help. How can I prevent Chrome from offsetting newly opened Window? When I open a new Window in Chrome on Windows 7 (by pressing CTRL+N), the new window does not exactly overlap the existing window.   Instead it is offset to the right slightly.   So, immediately after opening a new window I have to manually move it to the left so that it uses the full screen real estate.   Is there a way to prevent this offset? Properties vs Methods Quick question: When do you decide to use properties (in C#) and when do you decide to use methods?  We are busy having this debate and have found some areas where it is debatable whether we should use a property or a method. One example is this:  public void SetLabel(string text) {     Label.Text = text; }   In the example, Label is a control on a ASPX page. Is there a principle that can govern the decision (in this case) whether to make this a method or a property.  I'll accept the answer that is most general and comprehensive, but that also touches on the example that I have given. No Dropbox top panel icon since update to 18.04 Make account merges propagate to chat When two accounts are merged, all the posts/votes are moved over to the "master" account, and the other account ("slave"?) is deleted. The merge is propagated network-wide, so a similar thing happens on each site.  But, this does not happen to the chat user. The "slave" chat user is kept, with a 404 parent profile link. I feel that the chat user should be merged as well, re attributing all the chat messages.  Thoughts? I am looking for idioms or informal/slang/colloquial expression for some people that make you think that they are able of building a skyscraper, constructing a spaceship, playing the piano better than Mozart or something very fancy that requires remarkable skills, but when it comes to practice they prove to be completely inadequate. In the Law of Reflection, the angle of incidence is equal to angle of reflection. Why is this true? This is clearly true experimentally, but how does one prove this true mathematically? When using sudo powers and calling gedit the top level menu with File Edit View Search Tools Documents Help is missing.  If I create user ID root and sign in once and call gedit will it create the necessary user configuration files that might fix this?  Will this also make the annoying error messages go away whenever I use sudo, gksu or pkexec as a regular user with elevated privileges togedit ?  Will there be other benefits with Nautilus and other Gnome derivative Ubuntu applications?  NOTE: by sudo powers you can google pkexec gedit 3.5k hits, gksu gedit 40k hits or sudo gedit 500k hits. I'm in the minority using the first method but I believe it will become the standard in Ubuntu 17.04.    June 12, 2017 Update Here are a list of errors you get when using pkexec gedit:  (gedit:13003): Gtk-WARNING **: Calling Inhibit failed: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files  ** (gedit:13003): WARNING **: Set document metadata failed: Setting attribute metadata::gedit-spell-enabled not supported  ** (gedit:13003): WARNING **: Set document metadata failed: Setting attribute metadata::gedit-encoding not supported  ** (gedit:13003): WARNING **: Set document metadata failed: Setting attribute metadata::gedit-position not supported   On this  there is a commitment to fix these distracting messages as of June 5, 2017. No indication is given for when the fix will be upstream nor if the functionality will be implemented or the error messages will simply disappear.  Note the bug report was filed over a year ago and over that time it only effects 18 people. Origin of the term "fun fact" Where does the term "fun fact" originate?-- namely, not with the compositional meaning but rather with the idiomatic usage to introduce some sort of unusual, esoteric, absurd or otherwise "controversial" fact? What do the words 'RELATED' and 'ESTABLISHED' individually signify in RELATED,ESTABLISHED state in iptables?