How can I pass the variable to the to RegEx?
How do you use a variable in a regular expression?
How to enable top bar background opacity? There is a way to change top bar background opacity in ubuntu 20.04 lts.  I installed the hide top bar extension but is not a option to change it. ffmpeg is not even cutting this and other mp4s to the nearest second I have a file  Other - Analogue Clock-JEJqy1Wlovw.mp4  which is just a download from     It's 2 minutes 13 seconds long.  I had some issues cutting it to the second.  I was able to use this command   ffmpeg -ss 0 -i infile.mp4 -c copy -t 60 output.mp4  to make a file that was 60 seconds, so no problem so far.  That's the file exactly 1 minute, no issue there so far.  C:\vids\a&gt;dir blahhclo.mp4   9,590,540 bytes  C:\vids\a&gt;   C:\vids\a&gt;mediainfo blahhclo.mp4 General Complete name                            : blahhclo.mp4 Format                                   : MPEG-4 Format profile                           : Base Media Codec ID                                 : isom File size                                : 9.15 MiB Duration                                 : 1mn 0s Overall bit rate                         : 1 278 Kbps Writing application                      : Lavf58.3.100  Video ID                                       : 1 Format                                   : AVC Format/Info                              : Advanced Video Codec Format profile                           : High@L4.0 Format settings, CABAC                   : Yes Format settings, ReFrames                : 3 frames Codec ID                                 : avc1 Codec ID/Info                            : Advanced Video Coding Duration                                 : 1mn 0s Bit rate                                 : 1 146 Kbps Width                                    : 1 920 pixels Height                                   : 1 080 pixels Display aspect ratio                     : 16:9 Frame rate mode                          : Constant Frame rate                               : 25.000 fps Color space                              : YUV Chroma subsampling                       : 4:2:0 Bit depth                                : 8 bits Scan type                                : Progressive Bits/(Pixel*Frame)                       : 0.022 Stream size                              : 8.21 MiB (90%)  Audio ID                                       : 2 Format                                   : AAC Format/Info                              : Advanced Audio Codec Format profile                           : LC Codec ID                                 : 40 Duration                                 : 1mn 0s Bit rate mode                            : Constant Bit rate                                 : 126 Kbps Channel count                            : 2 channels Channel positions                        : Front: L R Sampling rate                            : 44.1 KHz Compression mode                         : Lossy Delay relative to video                  : 40ms Stream size                              : 920 KiB (10%)    C:\vids\a&gt;   But I do have an issue when I try to cut it at the following times, and it's whether I try to cut the 1 minute one or the whole 2 min 13sec one.  If I cut with -ss 0 -t 1,   it produces a file that is 1s 22ms.  So that's not too bad that's fairly close to one second. 1.022 seconds is quite good for an attempt to cut one second.  If I cut with -ss 0 -t 2, it produces a file that is 3s 19ms   That is terrible! it's meant to be one second!  If I cut with -ss 0 -t 30 then it is fine it does 30s 1ms.  Or this video for example, also an mp4   C:\blah&gt;ffmpeg -ss 189 -i vid.mp4 -c copy -t 6 someoutput.mp4  C:\blah&gt;mediainfo someoutput.mp4   produces a duration of 8s 383ms  That is so wrong though 'cos it should be 6 seconds! So that is two seconds too long!  C:\blah&gt;ffmpeg -ss 191 -i vid.mp4 -c copy -t 6 someoutput2.mp4  C:\blah&gt;mediainfo output2.mp4   shows that ffmpeg produced a duration of 10s 403ms  which is crazily wrong 'cos the ffmpeg command specified 6 seconds!  So that's not just one second out, that is 4 seconds out!  That's almost 50% longer than it should be! Wi-Fi speed on my laptop with RTL8723DE is a bit slow and its range is also very low, what to do? My Wi-Fi connection seems to be very weak and the range is very low. It drops by two bars if I just move to the next room and by two if just step outside.  The speed is also not fast as compared to what I get from the router on my desktop .  My laptop is a HP laptop with RTL8723de module. Can anyone help me in bumping up my Wi-Fi speed?  Result of lspci -nnk | grep 0280 -A3:  03:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. Device [10ec:d723] Subsystem: Hewlett-Packard Company Device [103c:8319] Kernel driver in use: rtl8723de Kernel modules: rtl8723de Relation between intensity of light and refractive index Relationship between balloon size and pressure I see numerous websites talking about how a small balloon is at higher pressure than a big balloon. This is a fun counter-intuitive factoid... unless it isn't a fact at all.  Young-Laplace gives  $$T = \Delta p \frac R2 $$  Which means that for a given tension, increasing the radius does decrease the pressure. But why would the tension be constant? A latex balloon is like a 2D spring, right? So the tension in a inflated spherical balloon should be proportional to the surface area, correct?  $$T \propto R^2 $$  But this gives  $$\Delta p \propto R$$  Which means the bigger the balloon, the higher the internal pressure. Which, again, would be the normal intuition - but it would burst the bubble of some simplified explanations. (har har) How to pass arguments to addEventListener listener function? What's the main difference between int.Parse() and Convert.ToInt32 Riemann and Darboux Integral of a product of two functions Can I move the Unity launcher? I can’t get used to the new Unity system. I’d like to move the left Unity panel to the bottom of screen (like Windows 7 – more similar is better).  But I can't find a way. Is it possible? 3.8 GPA, but 3 Fs and 1 D on transcript How many attacks can a fighter with two-weapon fighting make at 5th level? I have a 5th level fighter with the Two-Weapon Fighting fighting style.   What is the number of attacks I can make?   I say 4 attacks, but others say 3 because they say the rule on page 72 states that I get (only) 1 extra attack. Convergence of exponential Brownian martingale to zero almost surely Define the exponential Brownian martingale as $N_t = \exp\left\{a W_t - \frac12 a^2 t \right\}$ which is a martingale with respect to the natural filtration of $W$ which stands for a standard Brownian motion.  I now want to prove that $N_t \rightarrow 0$ a.s. for $t \rightarrow \infty$. As $N_t$ is a martingale it is by definition in $L^1$ hence Doob's martingale convergence theorem tells us that there exists a $N_\infty \in L^1$ such that $N_t \rightarrow N_\infty$ a.s., but how could I prove that $N_\infty \equiv 0$? Any help is greatly appreciated! Consider a cement block of the same density as sea-water resting on the (perfectly polished) seafloor. I also assume the side-faces of the cement block are highly polished, so that no vertical hydrostatic forces can attack on them. A cable is attached to the top of the block.  My question ist: How much force must one apply to the cable before the cement block begins to lift off the seafloor?  The normal response would be to say that only a negligible force is needed - as the block is practically suspended in the water.  However, as the bottom surface of the cement block is not in contact with the water, it is NOT experiencing the hydrostatic pressure from below - only from above.  Before the crane starts lifting, the (zero-sum) forces on the cement block are:  $$F_{Seawater Pressure} +F_{Gravity on Cement Block} - F_{Seafloor Resistance} = 0$$  as the crane starts applying Force, the Seafloor will reduce its Resistance in the same measure, leaving the forces on the cement block zero:  $$F_{Seawater Pressure} +F_{Gravity on Cement Block} - (F_{Seafloor Resistance}+F_{Crane}) = 0$$  Just before the Cement block lifts, the Seafloor will stop applying Force and the Crane will be applying the only upward Force:  $$F_{Crane} = F_{Seawater Pressure} +F_{Gravity on Cement Block}$$  Once the Cement block lifts off the sea-floor, hydrostatic pressure kicks in on the lower cement surface, suspending the block, but before that - boy does it take a lot of force to lift it!  What is wrong with this reasoning? Why can't you add attributes to object in python? Why don't players get extra xp for large encounters? Based on the table Encounter XP Multipliers from the Basic Rules' DM section, Page 57, when you're building encounters in 5E, you include an XP modifier depending on the number of creatures your PCs will be fighting: 1.5x for a pair, 2x for 3-6 and so on. However, the PCs only get the base XP as a reward.     This doesn't change the actual xp reward ... just your calculations of how difficult the encounter is.   Why is this? After acknowledging that battles vs multiple opponents are more difficult, why not reward them as such? Hello,    This question is about the Command Line Developer Tools that are usually installed with xcode-select --install and updated via a software update from the Mac App Store (at least until macOS 10.13). I use the developer toolchain on a daily basis and it has always worked and updated without issues.    Today I've updated my mac from High Sierra 10.13.6 to Mojave 10.14.1, and I've lost the ability to update the Developer Tools.    After the update I've executed a terminal command that relies on the developer tools being installed. It was a command to update , although I don't think that the specifics matter, as I believe that any task that tried to access the developer tools would have triggered the same error message.    The error was:   xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun       The phrasing was new (maybe), but I thought that it was caused by the usual need to re-install the Developer Tools after some macOS updates.    Later I tried to dig a bit deeper into the failure, and found out that:  $ ls -l /Library/Developer/CommandLineTools/usr/total 0drwxr-xr-x  3 root  admin  96  4 Nov 19:32 share$ which xcrun/usr/bin/xcrun$ xcode-select -p/Library/Developer/CommandLineTools    Still, as I normally do, I entered the command to install and update the Developer Tools in the terminal:  xcode-select --install    This started the usual procedure: modal window to confirm, then request to accept the license agreement, followed by a progress bar. Except that it failed very quickly with an unexpected error:     Can&rsquo;t install the software because it is not currently available from the Software Update server.     I've tried several times, to no avail. It gets always stuck.    Sometimes, however, the failure causes the System Preferences to report a pending update:      If I open that preference panel it starts searching for updates, and it always finds nothing except the first time that it happened. The first time, it found this:          It literally suggested me to install the updates for macOS 10.11 and 10.13. I have no idea why.  I closed the preference without installing, and as I said it hasn't shown them again. There is also no update available in new Mac App Store.   Is this a known issue? Is there any way to resolve the problem?     Update  Of course I can download the Dev Tools for macOS 10.14 installer from .  Before installing them manually, though, I'm wondering if there is anything that's broken with the system. How do I get powdered mammoth tusk? Am I missing something? I can find plenty of tusks, but I just don't know if I can make them into powder myself or do I have to find them for sale? How does remittance work? How does it differ from direct money transfer? I have a bank account in Germany in which I receive my salary in Euros. I want to deposit a part of it in my Indian bank account for personal savings. My Indian bank account is in INR. As I see it, I have two options:   To use a remittance service that converts my Euros into INR and deposits in my account. I am not sure how it works. The service (which I know is reliable) I signed up for asks me to deposit Euros in a certain account ("funding") which will be converted to INR and deposited in my account. How does that work exactly? Use my bank's service to make a international bank transfer to my account. Is that even possible, given that my Indian account is in INR? Will I incur higher conversion fees and lower exchange rate?   In general, what are the pros and cons of each of the above methods? And are there any other methods? Block quote with big quotation marks Office 2016 Advanced Setup