How to set read/write permission for a flash drive? I have a 16 GB flash drive formatted as FAT. When I plug the flash drive into my Dell Laptop running Ubuntu 14.04, I can read and write with no problem, but when I plug the same flash drive into my Dell Tower running Ubuntu 16.04, it sets up as read only. Below are results for report file system disk space usage (df -Th) and list directory contents showing permissions (ls -la) at each location. I am logged in as user at both locations.  Why are the permissions showing up different at each location? What can I do to set the flash drive to read and write on the Dell Tower running Ubuntu 16.04?  I have tried sudo chmod 666 /dev/sdc1 but that has no effect on permissions. I have also tried sudo chmod 666 /media/user/EBC2-93C8 same thing.  Dell Laptop Ubuntu 14.04  $ df -Th /dev/sdb1      vfat       16G   72K   16G   1% /media/user/EBC2-93C8  $ ls -la /media/user drwx------  3 user user 8192 Jan 16 16:09 EBC2-93C8   Dell Tower Ubuntu 16.04  $ df -Th /dev/sdc1      vfat       16G   80K   16G   1% /media/user/EBC2-93C8  $ ls -la /media/user drwxr-xr-x  3 user user  8192 Dec 31  1969 EBC2-93C8     I tried the solution posted at    Unmount the flash drive from nautilus, but do not remove it.  sudo mkdir /media/flash sudo mount /dev/sdb1 /media/flash -o dmask=000,fmask=111   It did not work right away. I had to unplug the flash drive and plug it in again. Now it works! Will this fix persist even after I reboot?  Thanks!  Follow-up notes......  the media directory now has two sub directories: user and flash.  after I rebooted the Dell Tower Ubuntu 16.04 machine and plugged in the flash drive, it appeared in the user folder.  but it appears read/write privileges have returned.  sudo fdisk -l  Disk /dev/sdc: 15.1 GiB, 16225665024 bytes, 31690752 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x9c767207  Device     Boot Start      End  Sectors  Size Id Type /dev/sdc1  *     5968 31690751 31684784 15.1G  c W95 FAT32 (LBA)   df -Th  /dev/sdc1      vfat       16G  152K   16G   1% /media/user/EBC2-93C8   ls -la  total 16 drwxr-x---+ 3 root root 4096 Jan 16 17:39 . drwxr-xr-x  4 root root 4096 Jan 16 17:20 .. drwxr-xr-x  3 user user 8192 Jan 16 17:43 EBC2-93C8   what's the little plus sign doing there?  also, I tried several variations of chmod.  sudo chmod 666 /dev/sdc1 sudo chmod 600 /dev/sdc1 sudo chmod 666 /media/user/EBC2-93C8 sudo chmod 600 /media/user/EBC2-93C8   none seem to work. oh well.
How do I change permissions on a FAT32 formatted drive? I am using Microsoft Visual C++ on Windows and Qt Creator on Ubuntu. I can't change permissions on my flash drive (FAT32), even as root.  How can I change permissions on a FAT32 flash-drive?
is keyword in Python Find $f$ if $ f(x)+f\left(\frac{1}{1-x}\right)=x $ Find $f$ if $$ f(x)+f\left(\frac{1}{1-x}\right)=x $$ I think, that I have to find x that $f(x) = f\left(\frac{1}{1-x}\right)$ I've tried to put x which make $x = \frac{1}{1 - x}$, but this equation has no roots in real numbers. I'm having this XML document with namespaces and I want to extract some nodes using XPath.  Here's the document:  &lt;ArrayOfAnyType xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://tempuri.org/"&gt;   &lt;anyType xsi:type="Document"&gt;     &lt;Id&gt;5&lt;/Id&gt;     &lt;Title&gt;T1&lt;/Title&gt;   &lt;/anyType&gt;    &lt;anyType xsi:type="Document"&gt;     &lt;Id&gt;15&lt;/Id&gt;     &lt;Title&gt;T15&lt;/Title&gt;   &lt;/anyType&gt; &lt;/ArrayOfAnyType&gt;   What's the XPath expression going to be if I want to extract all "anyType" elements with xsi:type="Document"?  I've tried this:   //anyType[@xsi:type="Document"]   and it doesn't work: Print numbered paragraph after title with Biblatex My question is related with Biber and Biblatex (latest versions). I need to quote the number of a paragraph of an old Christian text which is published within a book printed nowadays.   More clearly, I'm working with this Biblatex item (it's in Italian):  @INBOOK{Clemente1984Lettera,   author = {Clemente di Roma},   title = {Lettera di Clemente Romano ai Corinti},   year = {1984},   booktitle = {I Padri apostolici},   editor = {Quaquarelli, Antonio},   location = {Roma},   pages = {41-92},   publisher = {Città Nuova} }   I quote it in a common LaTex file with the BibTex key:  \cite[42]{Clemente1985Lettera}   With a humanistic Biblatex style, the final citation is:  Clemente di Roma, Lettera di Clemente Romano ai Corinti, in "I Padri apostolici", edited by A. Quaquarelli, Roma 1985, p. 42.  Anyway, I need to quote specifically the n. 2 of the letter of Clement, so I have to print this number just after the title "Lettera di Clemente Romano ai Corinti". So, I'd like to have this citation:  Clemente di Roma, Lettera di Clemente Romano ai Corinti, n. 2, in "I Padri apostolici", edited by A. Quaquarelli, Roma 1985, p. 42.  Now, I can find no Biblatex field to store the "n. 2" text, and no way to print it after the title. Of course, I could create a specific item in the bibliographic file in which the title field, or another one which is supposed to follow it, contains the "n. 2" indication. Anyway, this solution is very bad to me, because I should fill my archive with items of specific citations, and not of single titles.  What I'm looking for is what I've already implemented in the Bibfilex citations system (), which is moreover far less powerful that Biber: the possibility to add a pipe in the postnote of a BibTex key to separate a possible indication of a number of a paragraph, to be printed just after the title, from the pages of the volume. So a key like that  \cite[2|42]{Clemente1985Lettera}   should print   Clemente di Roma, Lettera di Clemente Romano ai Corinti, n. 2, in "I Padri apostolici", edited by A. Quaquarelli, Roma 1985, p. 42.  Anybody knows how to do that with Biber and Biblatex?  Thanks. There are several spells that require the target to be "humanoid" such as , , etc.  However, if the target is Polymorphed after that spell has been successful, then what happens?  Does the change in form to Beast end the spell effects? Does it suppress the spell until the correct form returns? Does it do something else? This looks like a question asked , but it isn't.  $$T(n)=\begin{cases} T (\sqrt{n}) + 1 \quad &amp; \text{ if } n&gt;1 \\  1 &amp; \text{ if }n=1\end{cases}$$  My professor gave this to me in class yesterday. This is where I'm stuck:   $$T(n) =  T(n^{1/2})+1 =  T(n^{1/4})+2 = T(n^{1/8})+3 = \dots =   T(n^{1/ 2 ^k})+k$$  Now this will continue till  $$n^{1/ 2 ^k}=1$$  How do I proceed ahead? If I take log on both sides, then RHS becomes zero. How do I solve the relation?  I don't want to use the Master theorem, I want to know where and why am I stuck. Can I check iPhone, iPad, Watch battery on Mac? My goal is to have battery status of other Apple device on my Mac (preferably on menubar). I'd like to have a glimpse of the battery status of my iPhone, iPad, Watch, and Airpods.  I'm a user of Bitbar and iStat menu, but I haven't found any widgets can wirelessly check other Apple device's battery status.  What I know is that I can click the Wi-Fi icon on menu bar and it will show my iPhone battery status. To show the percentage, I have to option + click the Wi-Fi icon and hover over my mouse on the iPhone hot spot section. It's pretty clunky, but I guess at least the API is there.  I am also open to third party apps which can let me see battery status across devices. What are the best ways to improve a site's position in Google? What are the best ways to improve a site's position in the Google search results? Finding a basis for a certain vector space of periodic polynomials How might I schedule a C# Windows Service to perform a task daily? Run cmd.exe in Administrator mode without explorer.exe I've recently had trouble with explorer.exe not working.  I found a possible solution , using .  The problem is that I cannot "right-click Command Prompt, and then click Run as administrator", since explorer.exe does not work for even a second without crashing.  I tried to use the  to open cmd as administrator, but I get an error 1327 because I have a blank password.    My question is, is there any other way to run cmd.exe with admin privileges?  If not, is there any way to run sfc.exe without admin privileges?  If not, does anyone have solution to my original problem of explorer.exe stopping and restarting ad nauseam? Show that the following series of function defines a continuous differentiable function function in $\mathbb R$. $$\sum_{n=1}^{\infty}\frac{\sin (nx^2)}{1+n^3}.$$  We have , $|f_n(x)|=\left|\frac{\sin (nx^2)}{1+n^3}\right|\le \frac{1}{1+n^3}\le \frac{1}{n^3}=M_n \text{ (say) }$  As, $\sum M_n$ is convergent so, the given series is uniformly convergent. Also , each $f_n(x)$ is a continuous function in $\mathbb R$. So, the given series converges to a continuous function , say $f(x)$.  But how we can show that $f(x)$ is differentiable function ?  Please help... What is the simplest SQL Query to find the second largest value? Let $p &gt; 3$ be a prime such that $p \equiv 2 \pmod 3$. Define the elliptic curve $E$ over $\mathbb{F}_p$ by $y^2 = x^3 + 1$. Prove that $E(\mathbb{F}_p)$ consists of $p+1$ points.  Using Fermat's little theorem you can prove that $x^3 + 1$ is a bijection on $\mathbb{F}_p$. Hence, $$\#E(\mathbb{F}_p) = \#\{(x,y) \in \mathbb{F}_p^2 : y^2 = x^3 + 1\} + \#\{\infty\} = \#\{(x,y) \in \mathbb{F}_p^2 : y^2 = x\} + 1.$$ But then I am stuck trying to prove that $y^2 = x$ has $p$ solutions $(x,y) \in \mathbb{F}_p^2$. I was wondering how to list all the hardware info in my computer?   Both terminal and GUI solutions please. Is there a single utility to monitor most hardware's working status? Just like some software in Windows?   Thanks and regards! Implicit Differentiation Help I have to use implicit differentiation to find $\frac{dy}{dx}$ given:  $$x^2 \cos(y) + \sin(2y) = xy$$  I don't even know where to begin, I missed the class where we went over implicit differentiation, and because of that, I am completely stuck.   Thank you everyone.  Edit: I don't know how to make the equation look all nice and whatnot, so sorry about that What I am working with: I am running my self-made Arduino board (in the sense that I use the Arduino bootloader and code editor) at 3.3V, and powered from a Lithium ion battery, which is USB-charged by a corresponding Microchip charger IC.  What I am trying to achieve: I want to measure battery capacity once every minute or so. I have an LCD attached, so the idea is that the overall setup lets me know how the battery is doing at a given moment. The datasheet of the battery has a voltage versus discharge-level curve, and so by measuring the voltage of the battery, I can estimate the remaining capacity (very roughly but enough for me!).  What I did:   (EDIT: Resistor values updated and P-MOSFET switch added based on @stevenvh and @Jonny's suggestions).  I connected a voltage divider from the battery V_plus, with the larger "portion" going to an analog-read-pin (i.e., ADC) on the Arduino/Atmega chip. The divider is 33 KOhm-to-10 KOhm, thus allowing measurement up to 4.1 Volts maximum of the Li-ion battery from my 3.3V level microcontroller. Also, using one of the I/O pins connected to an n-channel MOSFET, I can switch the current through the divider only when I need the measurement. Here is a rough schematic (updated for a 2nd time based on suggestions of @stevenvh and @Nick):     My question:   How is my current setup? My only constraints are: (1) I would like to make a rough measurement of the battery capacity based on the voltage reading, as described above. (2) I would like to prevent the voltage divider from interfering with my charging IC's reading of battery presence (in my original setup, the divider sometimes caused the IC to misread presence even when the battery was absent). How to create polygons with straight lines and right angles in QGIS? When creating a polygon, how do I do it so that the lines are straight (90, 0 degrees, etc.) and when I create corners they can be right angles? For instance, how do I create a perfect square or rectangle? Why does my hard drive LED light blink every second? The light blinks faintly about once a second.   It is slowly driving me insane.  How do I find out which program is causing this, so I can disable it?  Acer 5274 laptop/core i3 Windows 7 Home Premium Hitachi HTS545050B9A300 hard drive In the Landau theory of phase transitions, is the order parameter a thermodynamic variable of state? In the Landau theory of phase transitions, one typically considers a "free energy" $F$ as a function of the temperature $T$ and the "order parameter" $\psi$: $F(T, \psi)$.  For the sake of clarity, let's consider the liquid-gas transition, in which the order parameter is usually taken to be the difference of densities between the ordered phase and the disordered phase.  In this case, it looks that the order parameter $\psi$ is closely related to the the volume $V$, a global variable of state.  What is the correct interpretation of $\psi$ as a thermodynamic variable?   I consider several logical possibilities, but all interpretations look troublesome to me:    $\psi$ is a variable of state replacing the volume. In this case I have a few related concerns:   Is the "free energy" $F$ the Helmholtz or the Gibbs free energy?    If $F$ is the Gibbs free energy, $F$ should depend on the temperature $T$ and the pressure $p$ (the conjugate variable of the volume), so it shouldn't depend on $\psi$.  If it is the Helmholtz free energy, it's ok that it depends on $\psi$, but the experiments are usually carried out at constant pressure, not constant volume.  Usually, state variables are something one can select at will [for instance, think of the phase diagram $(p, T)$]. However, the order parameter $\psi$ is not selected at will, but it is selected by the system as a result of the minimization process according to the Landau theory.  $\psi$ is yet another variable of state in addition to volume and temperature.    Why the pressure is not usually taken into account as a variable of state, and only the temperature is considered? What is the conjugate variable to $\psi$? Can really $\psi$ and $V$ be taken as independent?  $\psi$ is not a variable of state, is something else.   What else can $\psi$ be from the thermodynamic point of view? Same question as above, why is pressure not usually taken into account in Landau theory?