I'm looking for an automatic way to lock out our home computer during certain pre-scheduled times of the day.  Rather than rolling my own script for doing this, is there some off-the-shelf software for this use-case?  In case this matters, the solution need not be absolutely bullet-proof.  I just need to raise the "activation barrier" just high enough to discourage casual use of the computer.
Access to our computer (not only to the internet) needs to be restricted for the accounts of my kids (7, 8) until they are old enough to manage this by themselves. Until then we need to be able to define the following:   the hours of the day when computing is o.k. (e.g. 5 - 9 pm) the days of the week when computing is not o.k. (e.g. mondays to fridays) the amount of time allowed per day (e.g. 2 hours)   In 11.10 all of the following that used to do the job don't work any more:   : for > 11.10 no more available through the ppa. : command line alternative, but from 11.10 removed from the repositories. : Looks great but repeatedly crashes to force restarting X-server. So we can't use or recommed this program at the moment.   Are there any other alternatives?
So I need to compress a directory with max compression.   How can I do it with xz? I mean I will need tar too because I can't compress a directory with only xz. Is there a oneliner to produce e.g. foo.tar.xz? Non in front of hyphenated adjective Centering in tabularx and X columns How can I center the column when using X in tabularx environment like in this example?  \begin{tabularx}{\textwidth}{@{}lXXXXX@{}}  1 &amp; 2 &amp; 3 &amp; 4 &amp; 5 \\    \end{tabularx} Configure HAProxy to include host headers for different backends I am exploring the use of HAProxy as a balancer in front of a set of web apis that run on IIS.   node1.myapp.mycompany.com node2.myapp.mycomapny.com   We are currently using Host Headers to correctly resolve the right web application on IIS.  For example, we may have otherapp.mycompany.com running on the same server/port, but using Host Headers IIS knows which one to serve up.  My initial attempt at HAProxy left me with 404 errors, because I was not including the host headers in my request, and so IIS was serving back the default site bound to the given IP, and not resolving by host name.    The fix left me with something like this:  frontend localnodes     bind *:80     mode http     default_backend nodes  backend nodes     mode http     balance roundrobin     option forwardfor     reqirep ^Host: Host:\ node1.myapp.mycompany.com     server web01 node1.myapp.mycompany.com:80   This works great for a single backend, but I am left scracthing my head on how to include the correct host headers depending on which backend is serving up the request:  backend nodes     mode http     balance roundrobin     option forwardfor     reqirep ^Host: Host:\ node1.myapp.mycompany.com     server web01 node1.myapp.mycompany.com:80     server web02 node2.myapp.mycompany.com:80   The above does not work whenever node2 is used because it doesn't resolve correctly in IIS (node2 in this case is on a different server, and therefore different IP.  In fact, if they were running on the same server/ip I suspect the request work "work", but they would all be served by node1 per the host header).     Is it possible to set the host based on the url of the backend used to serve up the request? If so, this implies my checks also need to provide the correct host header based on backend, how would that be done?   Edit: Am using HA-Proxy version 1.7.9 2017/08/18  Let me give this just a little more background.  We used to have just myapp.mycompany.com serving up api requests.  We need to expand it.  Our clients will still call myapp.mycompany.com, but that will just point to the HAProxy, which will balance it out to node1.myapp.mycompany.com and node2.myapp.mycompany.com.  Our current server configurations have us binding a single IP address on each server, so we use host headers to resolve. How to get back a declined Outlook invitation I accidentally clicked "decline" on an Outlook invitation and now I can't reverse it -- the event has completely disappeared from my calendar!  How can I get back the event invitation and change my "Decline" to "Accept" or "tentative"? Prove that $\frac{ 5^{125}-1}{ 5^{25}-1}$ is a composite number What type of solder is safest for home (hobbyist) use? A subgroup of a cyclic group is cyclic - Understanding Proof I'm having some trouble understanding the proof of the following theorem  A subgroup of a cyclic group is cyclic  I will list each step of the proof in my textbook and indicate the places that I'm confused and hopefully somewhere out there can clear some things up for me.  Proof Let  G be a cyclic group generated by &quot;$a$&quot; and let H be a subgroup of G. If $H = {\{e\}}$, then $H \text{ = &lt;e&gt;}$ is cyclic. If $H \neq \space {\{e\}}$, then $a^n \in H$ for some $n \in \mathbb{Z}^{+}$. Let $m$ be the smallest integer in $\mathbb{Z}^{+}$ such that $a^m \in H$. We claim that $c = a^m$ generates H; that is, $$H \space = \space &lt;a^m&gt; \space = \space &lt;c&gt;.$$ We must show that every $b \in H$ is a power of c. Since $b \in H$ and $H \leq G$, we have $b = a^n$ for some $n$. Find $q$ and $r$ such that $$ n = mq + r \space \space \space \space for \space \space \space 0 \leq r &lt; m,$$  Alright this is the first part in the proof where I start to get confused. Where does the division algorithm come from and why are we using it? The proof continues as follows:  $$a^n = a^{mq + r} = (a^m)^q \cdot a^r,$$ so $$ a^r = (a^m)^{-q} \cdot a^n.$$ Now since $a^n \in H$, $a^m \in H$, and $H$ is a group, both $(a^m)^{-q}$ and $a^n$ are in $H$. Thus $$(a^m)^{-q} \cdot a^n \in H; \space \space \space \text{that is,} \space \space a^r \in H.$$  This is another point at which I’m a little confused. What exactly about $a^n$ and $a^m$ being elements of $H$ allows us to accept that $(a^m)^{-q}$ and $a^{n}$ are in $H$? The proof continues:  Since $m$ was the smallest positive integer such that $a^m \in H$ and $0$ $\leq r$ $&lt; m$, we must have $r = 0$. Thus $n = qm$ and $$b \space = \space a^n \space = \space (a^m)^q \space = \space c^q,$$ so b is a power of c.  This final step is confusing as well, but I think its just because of the previous parts I was confused about. Any help in understanding this proof would be greatly appreciated Does Quicksilver's walkman speed up with him? Sending form POST request to PHP I'm using Terminator version 0.97. Is there a way that I can scroll unlimited? In the current version I only can scroll back limited history How can I show that $y'=\sqrt{|y|}$ has infinitely many solutions? Show that the first order differential equation $y'(x)=\sqrt{|y(x)|}$ with intial value $y(1/2)= 1/16$ has infinitely many solutions on the interval [−1, 1].  My thought were to show that this equation has two solutions (just by ansatz, or just looking at the interval $]0, 1]$ to get $y'(x) = \sqrt{|y(x)|}$) and deduce from that that there must be infinitely many solutions since the solution set forms a vector space. I've got a nagging feeling this isn't the way to go though. Can anybody give me a hint where to look? Can someone give me some example code that creates a surface with a transparent background in pygame? Why would one limit username format? Many websites when ask you to create a new "username", will limit you in some way, most often like "username should only contain letters and underscores" or something alike.  This results in inability to use my email as username and forces me to come up with new unique string all the time.  What is the rationale behind this?  Why not just let users use their emails, as a simple to remember and always unique?   What is generally wrong with having symbols like *&amp;%$#@ as a part of username? Meaning of the chemical potential for a boson gas My lecturer told me that $\mu$, the , is zero or negative, and in the following example, mathematically it acts as a normalization constant. But is there any physical insight about why boson gas can be zero or negative? I think it is due to the fact the photon gas can pop up from nowhere (i.e. vacuum fluctuation). $$ f_{BE}(\varepsilon)=\dfrac{1}{e^{(\varepsilon-\mu)/(k_B T)}-1}$$ Context  In one of his most popular books , Terry Pratchett makes an entropy joke:     Knowledge equals Power, which equals Energy, which equals Mass   Pratchett is a fantasy comedian and every third phrase in his book is a joke, therefore there is no good reason to believe it.  Pratchett uses that madness to make up that a huge library has a tremendous gravitational push.  The question  I work with computers and mostly with encryption.  My work colleagues believe Terry Pratchett's statement because of entropy.  On the other hand, I believe, it is incorrect since entropy of information is a different entropy than the one used in thermodynamics.  Am I correct?  And if so, why do use the same name (entropy) to mean two different things?  Also, what would be a good way to explain that these two "entropies" are different things to non-scientists (i.e. people without a chemistry or physics background)? When transiting Moscow (SVO), citizens of which countries need a transit visa? How to setup Windows from an external hard drive? Is it possible to install Windows from an external hard drive?  I have Windows XP installed on my laptop, and I want to remove it and install Windows 7.  My Windows 7 installation is in an .iso format on an external USB hard drive.  Is it possible to install it or will I need to put in a DVD before I start installing? no Get More in Plugin Manager in qgis 2 + ubuntu 13.04 After upgrade of qgis 1.8 to qgis 2.0 I couldn't find the choice "Get more" in Plugin Manager and I can't install plugins. I have the following code that shows either a bug or a misunderstanding on my part.  I sent the same list, but modified over an ObjectOutputStream.  Once as [0] and other as [1].  But when I read it, I get [0] twice.  I think this is caused by the fact that I am sending over the same object and ObjectOutputStream must be caching them somehow.  Is this work as it should, or should I file a bug?   import java.io.*; import java.net.*; import java.util.*;  public class OOS {      public static void main(String[] args) throws Exception {         Thread t1 = new Thread(new Runnable() {             public void run() {                 try {                     ServerSocket ss = new ServerSocket(12344);                     Socket s= ss.accept();                      ObjectOutputStream oos = new ObjectOutputStream(s.getOutputStream());                     List same = new ArrayList();                     same.add(0);                     oos.writeObject(same);                     same.clear();                     same.add(1);                     oos.writeObject(same);                  } catch(Exception e) {                     e.printStackTrace();                 }             }         });         t1.start();          Socket s = new Socket("localhost", 12344);         ObjectInputStream ois = new ObjectInputStream(s.getInputStream());          // outputs [0] as expected         System.out.println(ois.readObject());          // outputs [0], but expected [1]         System.out.println(ois.readObject());         System.exit(0);     } }