I have a partially downloaded video file (the download was paused). It is a large file and a significant portion has already been downloaded. I accidentally renamed it to .mp4 and its format got changed to .mp4. But I need to convert it back to .part to resume the download. I tried renaming it to .part but that didn't change its format, just the name got changed.  How do I convert the file to .part format?
Basic question, how do I resume interrupted / failed downloads in Firefox?
As the question title suggests, how do I see that every left ideal of a square matrix ring over a field is principal? Nothing can ruin your day like a poorly-written bug report.  I've seen several sets of guidelines for bug reporting in different organizations. In your opinion, what guidelines/steps are most essential for good bug reporting?  Feel free to share complete guideline recommendations from prior/current projects/organizations. What keeps mass from turning into energy? I understand the energy and mass can change back and forth according to Einstein. It is fluid; it can go from one to the other. So, what keeps mass from just turning into energy? Is there some force holding a subatomic particle together? What keeps mass in it's state? I hope this is not a silly question but I am clueless. Thanks Is there a way to combine custom settings with custom labels ? So that the output from a setting value would be a custom label ?   To explain:  In example, we have an international organisation, and say countries are stored as an ISO code. As this is a limited and stable set of data, using custom settings would be the appropriate way to deal with say the full country name.   The issue arises when I do not just want to store the English country name, but want to have it translatable, presenting the right translation depending on the user's locale. Now, this is the point where I'd like to integrate custom settings with custom labels.  So that say the custom setting with name 'some iso code' doesn't return the full country name, but Label.Country'some iso code', which is than automatically translated in the right version.   Sounds good right. But as custom settings are fixed to certain types, as far as I've gotten is put the label name in the settings as a string value. And then .. i'm stuck :).  No way to cast a string to a Custom label, or have it be interpreted (and translated) as such, or is there ?   I'm aware this can be done in a custom object &amp; apex, I was hoping for a more automated, "cleaner", less resource consuming way, better integrated, configurable way.  Additional clarrification: *The goal is to extend the use of custom labels (translation workbench), by adding a mapping from any data-based value to a custom label.*   While we could do a long matching process in apex, it would be faster &amp; neater if the custom settings mechanism could be used. There are disadvantaged to custom objects, they require soql &amp; apex, while custom settings &amp; custom labels are cached. They too can be used in many other places. Countries were an example, I'd use this mechanism for every variable value that needs to be translatable. Distribution of orbital velocities in a disk galaxy for N-body simulation? Can we get a flag history for chat's moderator attention flags? I checked my  to see whether I can find something similar to the main-site flag-history for chat-flags, but didn't find anything. I recently had the (dis)pleasure of regularly having to deal with a user, that has been deleted multiple times. Whenever they show up (with the same nick-name) again I have to flag them again. I'd like to get an overview of how often I had to do that, and whether my flags were helpful for the moderators. As such I propose the implementation of a flag-history as it is already in place for the main-site for chat-flags, that request moderator intervention. To be completely clear I am not talking about the 10k user flags, which are acted on in a matter of sometimes seconds with instantly visible results, but about moderator attention flags from this menu: Where do the X-Men get all their money/funding? Charles Xavier's father was a "wealthy nuclear scientist". In the beginning, Charles personally bankrolled the Xavier Institute/X-Men using his family's money.   This included, but was not limited to things like upgrading the mansion to house the training levels, providing a helicopter (the predecessor to the Blackbird jet), providing and replacing uniforms, providing health care for injured students, and rebuilding/repairing the mansion and parts of the Danger Room  repeatedly.  These have all been recurring costs. The mansion has been damaged or outright destroyed a ridiculous number of times. X-Men can't get into a fight without someone's uniform getting damaged.   In one of the more recent stories (I believe it was an early issue of Wolverine &amp; The X-Men), a comment is made about how the X-Men are pretty much bankrupt.  Where has all this money come from over all these years?   Xavier may have had a large war chest to start with, but no other income has ever been mentioned to my knowledge. Student's tuition could account for some of it, but there's no way that's going to fund everything. Given $f = f(u(t), t)$, is it possible to find the following derivative? ($f$,$u \in \mathbb{R}^n$, $t \in \mathbb{R}$)  $$ \frac{\partial f}{\partial||u||^2_2} $$  I am aware of the following derivatives:  $$ \frac{\partial||x||^2_2}{\partial x} = \frac{\partial ||x^Tx||_2}{\partial x} = 2x $$  So I can invert it to give me (elementwise division in the RHS)  $$ \frac{\partial x}{\partial||x||^2_2} = \frac{1}{2x} $$  This step does feel like abuse of notation I find it hard to convince myself of its validity.  If it's right though, I could just apply the chain rule to find  $$ \frac{\partial f}{\partial u} \frac{\partial u}{\partial||u||^2_2} $$  However, knowing that both $f$ and $u$ are a function of $t$, I am somehow doubting my own reasoning. Or does that just mean that the derivative will still be a function of $t$ and I have nothing to worry about? Can anyone shed some light?  UPDATE: I'm now doubting the existence of  $$ \frac{\partial u}{\partial ||u||^2_2} $$  because $u = u(||u||_2^2)$ is not injective. Is the inversion step I did above legitimate? Is there another possible approach? Aliens like giant grasshoppers invade earth, give black people power over whites I have four competing models which I use to predict a binary outcome variable (say, employment status after graduating, 1 = employed, 0 = not-employed) for n subjects. A natural metric of model performance is hit rate which is the percentage of correct predictions for each one of the models.   It seems to me that I cannot use ANOVA in this setting as the data violates the assumptions underlying ANOVA. Is there an equivalent procedure I could use instead of ANOVA in the above setting to test for the hypothesis that all four models are equally effective? Creating multiline strings in JavaScript I have a bunch of files as follows:  04602635_b0294.DAT20120807164534 04602637_b0297.DAT20120807164713 04602638_b0296.DAT20120807164637 04602639_b0299.DAT20120807164819 04602640_b0298.DAT20120807164748 04602641_b0300.DAT20120807164849 04602650_b0301.DAT20120807164921 04602652_b0302.DAT20120807164956   I need to rename them to exclude the prefix. It needs to look like this..  b0294.DAT20120807164534 b0297.DAT20120807164713 b0296.DAT20120807164637 b0299.DAT20120807164819 b0298.DAT20120807164748 b0300.DAT20120807164849 b0301.DAT20120807164921 b0302.DAT20120807164956   EDIT  I forgot to add that I am using Solaris. "Inspirational" quote at start of chapter How to find the 'sizeof' (a pointer pointing to an array)? First off, here is some code:  int main()  {     int days[] = {1,2,3,4,5};     int *ptr = days;     printf("%u\n", sizeof(days));     printf("%u\n", sizeof(ptr));      return 0; }   Is there a way to find out the size of the array that ptr is pointing to (instead of just giving its size, which is four bytes on a 32-bit system)? I have some conditions for some background job to run:  condition-command &amp;&amp; condition-command &amp;&amp; background-job &amp;   The problem is: I want the conditions to block until the job runs, as if I had run:  condition-command; condition-command; background-job &amp;   But it isn't a condition, if previous command fails I do not want the job to run.  I realised it is asynchronous, but it should not, in my mind the both following scripts should be the same, but they do not:  sleep 2; echo foo &amp; sleep 1; echo bar; wait   # prints foo, then bar: correct sleep 2 &amp;&amp; echo foo &amp; sleep 1; echo bar; wait # prints bar, then foo: bug   I know if I test $? variable it would work, or if I put the last one inside a subshell (but then I would lost job controls, I want to avoid daemons), but I want to know why bash make it this way, where is it documented? Is there any way to prevent this behaviour?  Edit: Chained ifs is disgusting, that is why I will not accept it as a alternative way. Edit 2: I know a subshell is possible, but it will not work for me, let us imagine I want to run a bunch of commands then wait in the end. It will be possible if i check the existence of /proc/$PID directory, but it would be a pain in the neck if there are several jobs. Edit 3: The main question is WHY bash does it, where is it documented? Whether or not it has a solution is a bonus! When using the ssh or ftp commands from the Bash shell, does the server that I am connecting to learn of the domain name used? I understand that the domain name is locally translated into an IP address via DNS. In HTTP, after that happens, the server is told the original domain name as well in order to serve the correct page, or to present the correct TLS cert (SNI).  host serverfault.com GET /   Does a similar phenomenon happen when connecting to ssh or ftp?  I ask because I am  trying to ssh into a server (GoDaddy webhosting) which expects a domain name, but is not letting me in when I try to connect via user@IPaddress as the DNS is not yet moved to the GoDaddy IP address. If $f \colon [a,b] \rightarrow \mathbb{R}$, then show that there exists $c \in [a,b]$ such that $\int_a^c f = \int_c^b f$ If $f \colon [a,b]\rightarrow \mathbb{R}$, then show that there exists $c \in [a,b]$ such that $c \in [a,b]$ such that $\int_a^c f = \int_c^b f$.  I think that I have to proceed with the Mean Value Theorem of Integrals... Why is the console window closing immediately once displayed my output? Making a Laser in Cycles - Straight Beam of Light? Please help solve 'oracle-java7-installer' missing. Error below  dpkg: warning: files list file for package !['oracle-java7-installer' missing;][1]  assuming package has no files currently installed (Reading database ... 302933 files and directories currently installed.) Removing linux-image-extra-3.8.0-19-generic ... /var/lib/dpkg/info/linux-image-extra-3.8.0-19-generic.postrm: 6: /var/lib/dpkg/info/linux-image-extra-3.8.0-19-generic.postrm: Syntax error: ")"  unexpected dpkg: error processing linux-image-extra-3.8.0-19-generic (--remove):  subprocess installed post-removal script returned error exit status 2  Errors were encountered while processing:  linux-image-extra-3.8.0-19-generic  E: Sub-process /usr/bin/dpkg returned an error code (1) A package failed to install.  Trying to recover: