Ubuntu, being a distribution derived from Debian, uses installer packages with extension .deb whereas other distributions like Fedora, CentOS, OpenSuse, Mandriva ... etc, use .rpm installers.  Many packages on the internet are only packaged in rpm.  If we have a system based on Debian as it may be Ubuntu it is possible to install these packages rpm in the system without harming it.
I have a burning desire to install RPMs onto my Ubuntu installation - is this possible? Can I use Yum - or another RPM Package Management tool?
Create a trigger on all the last_modified columns in PostgreSQL In PostgreSQL 9.5, I have tables with columns in the form   prefix_last_modified timestamp without time zone NOT NULL DEFAULT  (clock_timestamp() AT TIME ZONE 'UTC')   I was looking for a way to set the last modified value automatically updated at each update of the rows, and I found  that defined the function:  CREATE OR REPLACE FUNCTION update_modified_column()  RETURNS TRIGGER AS $$ BEGIN     NEW.modified = now();     RETURN NEW;  END; $$ language 'plpgsql';   Now, I'd like to know if there is any way to pass the column name to the PostgreSQL function and to execute it to the NEW row? E.g.  CREATE OR REPLACE FUNCTION update_modified_column(varchar column)        RETURNS TRIGGER AS $$     BEGIN         NEW.column = now();         RETURN NEW;      END; $$ language 'plpgsql'; Woman planning to visit me from Ukraine to the US applied for a visa and such, claims to have paid for the visa but needs 500 dollars more for the airfare from Ukraine to the US. She says strict rules apply that the airfare cannot be purchased by US person, and must be purchased in Ukraine by person applying for the visa because of terrorist issues, etc..   Is there truth to such? Cardinality of the Cartesian Product of Two Equinumerous Infinite Sets Is the cardinality of the Cartesian product of two equinumerous infinite sets the same as the cardinality of any one of the sets? I couldn't find this explicitly stated in any handout or text. This certainly seems to be true from the examples I have seen:  The Cartesian product of two infinitely countable sets is again infinitely countable. The Cartesian product of two sets with cardinality of continuum again has cardinality of continuum. How to remove `t=canonical` from Firefox browser searches made on DuckDuckGo? Get tax deduction for expensive car expense What could be the reason, that private keys are not unlocked? Since I updated to Ubuntu 17.10 a while ago, my private keys – the which I use for example to access my server via ssh – are not unlocked programmatically after login anymore.    My understanding is, that usually the seahorse client should take care of this, by asking you whether or not to store the key's password when typing them in for the first time.  My first guess was, that seahorse-daemon wasn't running for some reason, but it is:  user@Zeus:~$ ps aux | grep seahorse user    19170  0.0  0.1 432636 26564 ?        Ss   00:07   0:00 seahorse-daemon   My second guess was, that for some reason I have to delete all related passwords stored in seahorse under »Passwords->login«:    I was hoping to force the client to ask me again and then storing them again. But this didn't help either. The client does not pop up to ask me...  Then I found this question, which could be related, but did not help me:    As the management of other passwords work as expected (for example passwords for nautilus, Chromium, Nextcloud etc.) I assume the problem has to do something with ssh-agent...  Can anybody hint me in the right directions, how to solve this problem? Has anything changed in the way how GNOME handles passwords? Maybe some new fancy program failed being installed during the upgrade process?   UPDATE When I add the private key to the authentication agent again with:  ssh-add ~/.ssh/id_rsa   and try to log in, I will be asked to unlock the key only once, after that the key gets unlocked programmatically. But this works only until the next reboot. After a fresh start, I have to add the key again... I want to detect when someone is building a lever, then replace it with another lever that has the canplaceon tag so it can be placed on a redstone_lamp  How can I clear the crafting item and replace it with one that has a canplaceon tag? How to move from screen 1 to screen 3 by moving cursor to the left and vice versa? If I have to move the mouse from the left screen all the way to the right screen, the distance is quite big.   Is there a way to virtually connect the sides of the screen as if they were arranged in a circle? I could then move from the left screen to the right screen, by simply moving the cursor to the left. Connecting multiple grounds As I'm relatively new to the electronics world, I was wondering if you can connect multiple  ground terminals (corresponding to several different voltage outputs) to the same ground. Or do they each need their own?  In my case I have 5 lines, one 12V, one 3.3V, two 5V and one variable from a 12V in using a  voltage regulator that already has its own ground. So I'm guessing that each would need its own ground, but it is never bad to ask. I am a beginner with Fourier series and I have to evaluate the sum   $$\sum_{n  =1}^{\infty}{\sin\left(n\right) \over n}$$  I don't know which function I have to take to evaluate the fourier series ... Someone can give me a hint ?  Thanks in advance! Access a glyph on fontspec using a GID (Glyph ID) I'm trying to access a glyph, but it's only mentioned in the "Basic Latin and Latin 1" set for a font. The glyph has no name or unicode ID, but it does have a glyph ID or GID. fontspec doesn't mention possibilities for using this glyph. Neither does Adobe in the adobe feature file syntax:   I'd still like to be able to access a glyph through its ID, since it's the only way I can access it (I think).  My specific case requires to access the glyph ID 554 from Stevens Titling Pro Sable Brush. I will only post this font if it's strictly necessary, since I don't like to distribute these fonts to the wide world.  I posted an MWE containing another (free) font. This is not the font I intend to use, but perhaps a starting point to try and access glyphs manually.   \documentclass{article}  \usepackage{fontspec} \setmainfont{EB Garamond}  \parindent=0pt \begin{document}  Some text int EB Garamond. How can I access glyph 123 now?  \end{document} How to echo a bang! I tried to create a script by echo'ing the contents into a file, instead of opening it with a editor  echo -e "#!/bin/bash \n /usr/bin/command args"  &gt; .scripts/command   The output:     bash: !/bin/bash: event not found   I've isolated this strange behavior to the .  $ echo ! !    $ echo "!" bash: !: event not found  $ echo \#! #!  $ echo \#!/bin/bash bash: !/bin/bash: event not found    Why is bang causing this?   What are these "events" that bash refers to?     How do I get past this problem and print "#!/bin/bash" to the screen or my file? How to open a new Terminal with shell prompt and running multiple commands in Command Line? I want to Open a new Terminal in from within terminal.  It should have Shell prompt as well as already run few commands.  How to do it ? Words with different meanings in American and British English This is similar to , but not quite the same.  There are quite a few words which have totally different meanings in American and British English and which are likely to cause confusion when heard by non-local speakers.  What are they?  We are looking for the same word with different meanings (for example jumper), and not words which are different between the two dialects (for example truck and lorry). Joint distribution of a Normal and Truncated Normal I have a random variable $X\sim \text{Normal}(\mu,\sigma)$ and have the transformation $Y=\max\{0,X\}$.  Is the distribution of $Y$ a truncated normal where it is truncated to live on the positive half of the real line?  Secondly, is there a closed form solution for the joint distribution of a Normal random variable and a truncated Normal random variable? Are all electrons identical? Why should two sub-atomic (or elementary particle) - say electrons need to have identical static properties - identical mass, identical charge? Why can't they differ between each other by a very slight degree? Is there a theory which proves that?  Imagine an alien of size of order of Milky-way galaxy examining our solar system with a probe of size of 10's of solar system dimension and concludes that all planets are identical. Why rationalize the denominator? In grade school we learn to rationalize denominators of fractions when possible. We are taught that $\frac{\sqrt{2}}{2}$ is simpler than $\frac{1}{\sqrt{2}}$.  says that "there is a bias against roots in the denominator of a fraction". But such fractions are well-defined and I'm failing to see anything wrong with $\frac{1}{\sqrt{2}}$ - in fact, IMO it is simpler than $\frac{\sqrt{2}}{2}$ because 1 is simpler than 2 (or similarly, because the former can trivially be rewritten without a fraction).  So why does this bias against roots in the denominator exist and what is its justification? The only reason I can think of is that the bias is a relic of a time before the reals were understood well enough for mathematicians to be comfortable dividing by irrationals, but I have been unable to find a source to corroborate or contradict this guess. How to UPSERT (MERGE, INSERT ... ON DUPLICATE UPDATE) in PostgreSQL? To reopen a closed question,  must agree that the question is suitable for the site and cast votes to reopen the question. But:  How does one actually vote to reopen? Is there a reputation level that you must have before you can see this function? Or do I just leave a comment along the lines of, &quot;I vote to reopen&quot;? What happens if someone with less than 3000 reputation leaves a comment that they wish to vote to reopen? How can one draw attention to their closed questions? Is it done via a posting new question? Or do you edit the closed question?   Related:  For more information, see &quot;&quot; in the . Insert a paragraph into a list that uses the whole text width