Next Friday, I'm going on a 3 day road trip to Spain, and then will stay there for 3 weeks. I will come back in the first week of January.  The problem is that because of the Gilets Jaunes, France is currently in a bit of a mess, to put it mildly: there are frequent riots and blockades, many gas stations have run out of fuel and a number of locations have seen arson and even deaths. It doesn't seem like it's going to stop in the next week, and I've even heard rumours on social media that this might be the start of a new revolution, similar to what happened 50 years ago.  The plan right now is to stay the night somewhere in the middle of France (I think near Poitiers), then drive to Zaragosa via San Sebastian and spend the night and part of the next day there and then drive from there to the Costa Blanca, the end destination of the trip. The trip back would be a 2 day trip on Friday and Saturday with a stay in France, probably in Poitier again.  I'm somewhat concerned about the situation and really want to avoid problems on the trip. I don't want to end up on the side of the road without fuel, I don't want to have to spend the night in a car and I DEFINITELY do not want to end up getting caught in the middle of a riot or worse. Postponing the trip is not an option and we really want to go with a car and not a plane or train.  What things should I be aware of to make the trip go smoothly? Note: I won't be visiting Paris on this trip, so the suggested duplicate isn't quite valid. I will spend most of my time in France on the motorways and the roadside rest stops.
I’ve a date and I really waited long to make this happen. My gifrfriend is a bit worried about the security issue in Paris. Which locals think that the media is exagerrating the issue and the issue is small and non-threatening for tourists?
How to show that $|D_{2n}| = 2n$ via the presentation? Consider the dihedral group  $$D_{2n}= \langle a,b \mid a^n = 1 = b^2, b^{-1}ab = a^{-1}\rangle$$  How can I show that $|D_{2n}| = 2n$?   I'm trying to show that we can write every element in the form  $$x = a^i b^j$$ where $i= 0, 1, \dots, n-1$; $b = 0,1$.   I managed to show existence, and it is clear that there are $2n$ such elements, so if I can show that every choice of $i,j$ gives a distinct element, I'll be done.  Any ideas? Holomorphic function $\varphi$ with fixed point $z_0$ such that $\varphi'(z_o)=1$ is linear? I've just happened to read this  on MO (that of course has been closed) and some of the answers to a similar  on MSE.   I know almost nothing of nonstandard analysis and was asking myself if something like the sentence « $1- 0.999 \dots$ is a nonzero positive infinitesimal» could be easily expressed and proved in nonstandard analysis.  First of all, what is 0.999... ? If we take the usual definition as a series or as a limit of a sequence of rationals, then it will still be a real number and equal to $1$ (I guess by "transfer principle", but please correct me if I'm wrong).  Instead, let's define  $$0.9_N:=\sum_{i=1}^N 9\cdot 10^{-i} $$  where $N\in{}^*\mathbb{N}\setminus\mathbb{N}$ is an infinite nonstandard natural number. This $0.9_N$ is a legitimate element of ${}^*\mathbb{R}$, expressed as $0.$ followed by an infinite number of "$9$" digits.  What can be said about $\epsilon_N:=1-0.9_N$ ? Is there an elementary proof that $\epsilon_N$ is a positive infinitesimal of ${}^*\mathbb{R}$ ? (by "elementary" I mean just order and field axioms and the intuitive facts about infinitesimals, like that for $x$ infinite $1/x$ is infinitesimal etc.; no nonprincipal ultrafilters &amp; C). Cyberpunk/Post-Apocalyptic Sci-Fi series from the 90s or 00s based in Manhattan List AppDomains in Process How to fix sudo after "chmod -R 777 /usr/bin"? I entered chmod -R 777 /usr/bin and now sudo is not working.  It says sudo must be setuid root.  Some advice online said to run chown root:root /usr/bin/sudo chmod 4755 /usr/bin/sudo.  On entering chown root:root /usr/bin/sudo it shows an opened in readonly mode error. I am having trouble proving the statement:     Let $$S = \{m + n\sqrt 2 : m, n \in\mathbb Z\}$$ Prove that for every $\epsilon &gt; 0$, the intersection of $S$ and $(0, \epsilon)$ is nonempty. For whatever reason, we do no longer need to be root (or using sudo) to run /sbin/shutdown, /sbin/reboot etc.  This seems to be because those executables are now symlinks to /bin/systemctl which handles everything as normal user.  However, what if I want shutdown and reboot to require root authentication again? How can I achieve this? I have connected speakers to the back panel of my computer at work and I would like to have them always enabled (I can switch them off on the speaker casing). However when I connect headphones on the front panel system automatically says that the rear output is unplugged.  I found a solution to disable auto detection with Alsamixer and it works almost ok except the fact that after system restart I need to reconfigure the settings again... How can I set this once and forget about it? Make sure only a single instance of a program is running Is there a Pythonic way to have only one instance of a program running?   The only reasonable solution I've come up with is trying to run it as a server on some port, then second program trying to bind to same port - fails. But it's not really a great idea, maybe there's something more lightweight than this?    (Take into consideration that program is expected to fail sometimes, i.e. segfault - so things like "lock file" won't work) Java FileReader encoding issue I tried to use java.io.FileReader to read some text files and convert them into a string, but I found the result is wrongly encoded and not readable at all.  Here's my environment:   Windows 2003, OS encoding: CP1252 Java 5.0   My files are UTF-8 encoded or CP1252 encoded, and some of them (UTF-8 encoded files)  may contain Chinese (non-Latin) characters.  I use the following code to do my work:     private static String readFileAsString(String filePath)     throws java.io.IOException{         StringBuffer fileData = new StringBuffer(1000);         FileReader reader = new FileReader(filePath);         //System.out.println(reader.getEncoding());         BufferedReader reader = new BufferedReader(reader);         char[] buf = new char[1024];         int numRead=0;         while((numRead=reader.read(buf)) != -1){             String readData = String.valueOf(buf, 0, numRead);             fileData.append(readData);             buf = new char[1024];         }         reader.close();         return fileData.toString();     }   The above code doesn't work. I found the FileReader's encoding is CP1252 even if the text is UTF-8 encoded. But the JavaDoc of java.io.FileReader says that:     The constructors of this class assume   that the default character encoding   and the default byte-buffer size are   appropriate.   Does this mean that I am not required to set character encoding by myself if I am using FileReader? But I did get wrongly encoded data currently, what's the correct way to deal with my situtaion? Thanks. Identify an unknown IP in our network I have a network containing 20 clients. I assigned IP range 10.0.0.1 to 10.0.0.20 to them. When I do an IP scanning I see someone using 10.0.0.131 in VMware. How can I find out which IP is this IP bridged with? i.e How can I find out which system has 2 IP? (i.e the other IP of this system)  Update:  My system IP in the network is 10.0.0.81:    Output of the IP scanner show someone using 10.0.0.131 in VMware:    And the result of tracert command show nothing between us:  C:\Users&gt;tracert -j 10.0.0.131 10.0.0.81  Tracing route to ghasemi3.it.com [10.0.0.81] over a maximum of 30 hops:    1    &lt;1 ms    &lt;1 ms    &lt;1 ms  ghasemi3.it.com [10.0.0.81]  Trace complete. C:\Users&gt; How do I run wireshark, with root-privileges? A standard installation of Wireshark doesn't give the program permission to access the network interface.   I suppose I have to run the program with sudo, but do not know how to add it to the icon - if that's the way to do it. Today a couple of buffer overflows in NTP were announced , . It looks like updating my system to fix these issues is in order.   How can I find out if they have been fixed in the Ubuntu repositories, such that if I were to run:   sudo apt-get update sudo apt-get upgrade   then the fix would get installed and the vulnerability closed?   Edit: The selected answer specifically addresses the question of how to identify if a given CVE has been fixed or not, "Does Ubuntu generally post timely security updates?"  is certainly related but not identical Terminal not opening up after upgrading python to 3.7 I have upgraded python to version 3.7 and now my terminal is not opening up.  I followed this post   Commands I ran are as follows,  sudo apt-get install python3.7 sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.6 1 sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.7 2 sudo update-alternatives --config python3   Entered 2 for python3.7  I can't open terminal and run commands.  My ubuntu version is, Ubuntu 18.04.2 LTS Derivative of determinant of a matrix I would like to know how to calculate:  $$\frac{d}{dt}\det \big(A_1(t), A_2(t), \ldots, A_n (t) \big).$$ Charm Person has verbal and somatic components.  Is there anything in the rules as written that defines how obvious those verbal and somatic components are?  Would it be obvious the caster was casting a spell from 5 feet away?  From across a crowded room?  I'm specifically interested in an answer based on the rules as written, although interpretation and individual opinion are not unwelcome. My Ubuntu version 18.04 brings me a GNU GRUB version 2.02 and I cannot access my entry password panel? I have Lubuntu 16.10 installed on my disk mounted as /.  The problem is that the CUPS log file( /var/log/cups/error.log)  grows all the time until I no have free space left on the disk...   So when I delete that file, the space on disk freed up again  I already tried:    fsck disk usage analyzer every apt-cleaning/autocleaning, and dependencies fixing.    How should I proceed?  du -sxh:  9,0G    .  Model: ATA ST3160815AS (scsi) Disk /dev/sda: 160GB Sector size (logical/physical): 512B/512B Partition Table: msdos Disk Flags:   Number  Start   End     Size    Type      File system     Flags  1      32,3kB  50,3GB  50,3GB  primary   ext4            boot  2      50,3GB  160GB   110GB   extended  5      50,3GB  158GB   108GB   logical   ext4  6      158GB   160GB   2136MB  logical   linux-swap(v1)   parted --list &amp;&amp; sudo df -h:  Model: ATA ST3160815AS (scsi) Disk /dev/sda: 160GB Sector size (logical/physical): 512B/512B Partition Table: msdos Disk Flags:   Number  Start   End     Size    Type     File system  Flags  1      32,3kB  50,3GB  50,3GB  primary  ext4         boot  2      50,3GB  160GB   110GB   primary  ext4   Filesystem      Size  Used Avail Use% Mounted on udev            985M     0  985M   0% /dev tmpfs           201M  6,3M  195M   4% /run /dev/sda1        46G   43G  709M  99% / tmpfs          1003M  188K 1003M   1% /dev/shm tmpfs           5,0M  4,0K  5,0M   1% /run/lock tmpfs          1003M     0 1003M   0% /sys/fs/cgroup tmpfs           201M   36K  201M   1% /run/user/1000 /dev/sda2       101G   60M   96G   1% /media/aram/ Show  $$\int_0^\infty \frac{\ln(x)}{e^x} = -\gamma$$ (gamma is Euler-Mascheroni constant).  Can anyone please prove this result?  Also  $$ \int_0^\infty \frac{\left( \ln(x) \right)^2}{e^x}\mathrm dx. $$