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iPhone asks 'Trust This Computer' again (I am on macOS 10.14.6 and iOS 12.4)   I am certain that I have trusted my Mac before. Without the latter trust, I can also access the phone in iTunes.   I have tried reset "Location and Privacy" on my phone. Then   When connecting the iPhone with iTunes running, it asks for the trust and I trust it.  Reboot my Mac and the phone asks for another trust.   Is there some known malware mimics system behavior and steal data from an iPhone?  (I do have installed some pir*ted software recently. That's my fault.) Global auth is dead! Long live universal login I'm trying to include Arabic text in an English document (I'm a new latex user), but I can't seem to get any Arabic text to render at all, using xelatex or any kind of tex. I'm using texshop 3.51 on a mac. I can't get this basic example to work, it just displays question marks in the output pdf.  \documentclass[12pt]{article} \usepackage[utf]{arabxetex} \newfontfamily\arabicfont[Script=Arabic]{Amiri} \begin{document} \begin{arab}[voc] وَهَذِهِ فِقرَةٌ بِالعَرَبِيَة مَعَ كَلِمَة اِنكلِيزِيَة \end{arab} \end{document}     I've downloaded Amiri (and also Scheherazade and Lateef) into Fontbook, and they show up if I go Source->Font->Show Fonts in texshop. If I remove the Amiri part it still doesn't work.   Is there anything I can do? I've looked at other links here, like  and  but I can't even render any of those examples.   Thank you so much for any help! I'll love you forever if I can get this to work. How do I make a bootable Ubuntu USB? How do I make an Bootable Ubuntu USB containing the the latest version of Ubuntu?  For completeness, how would I be able to do this on Ubuntu, Windows, OS X or another Linux distro? Resampling GeoTIFF images to same resolution using QGIS I have two geotiff images that I would like to resample the same resolution. If I use ArcGIS Desktop this is easy to do but how do I do this using QGIS? Is Java "pass-by-reference" or "pass-by-value"? I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation? Which piece of equipment is holding me back? I am primarily an amateur photographer but I do take small jobs from time to time.  I'm looking to upgrade my equipment but I'm not sure if I should be spending money on my body, glass, or both.  I have two common issues that I'd like to improve.   I shoot a lot at ice rinks and find that even in servo mode I get a lot of shots that are slightly out of focus.  I try to keep the AF target on face masks but many shots will come out focused an inch or two off (ears, hands, etc).  I'm shooting F/1.8-F/2.8 to get action stopping shutter speeds so you can really tell when the focus is even a hair off.  I don't know if this is a limitation of my camera, lens, or the human operator. Most of my paid work is indoors shooting candids where a flash is inappropriate.  I feel like I need to use a higher F-number to get more subject in focus but I usually can't do it without upping to ISO 3200 unless I'm using a flash.  By the time I clean up the high ISO noise in Camera Raw I end up with an image lacking detail.  So far this hasn't been a big problem because the photos are typically used in magazine prints only an inch or two wide but it's still driving me nuts.   Here is the equipment currently in my bag:   Canon Rebel T2i Canon EF-S 18-55mm f/3.5-5.6 II (no IS)   Collecting dust, came with my old Rebel XTi.  Canon EF-S 18-135mm f/3.5-5.6 IS   Purchased with my T2i.  This is my workhorse lens but I'm disappointed with the soft images it produces at higher focal lengths.  Stopping down makes the images acceptable but that's not always an option.  My eyes want more contrast and color but considering how inexpensive this lens is I can't really complain.  Canon EF 70-300mm f/4-5.6 IS USM   This was purchased with an older camera and doesn't get used much anymore.  The images are too soft beyond 200mm and the AF seems sluggish.  Canon EF 50mm f/1.4 USM   I am extremely happy with the images I get from this lens.  I use it indoors all the time and also paired with extension tubes for some macro work.  Some of my best ice hockey images have been from this lens even though I didn't have sports in mind for this lens.    My initial plan was to upgrade to a 60D or 7D body but after doing some reading it occurred to me that I might invest in better glass first.  I'm unsure of what will help improve focusing, image quality, high ISO shooting, etc.  Maybe it's a new camera, new glass, photography lessons, or a little of everything?  I'm looking to keep my next round of purchases under $3,000 and am willing to trade in some of my used equipment to offset costs.  Would anyone care to make a recommendation?  I'm looking at the EOS 60D and 7D bodies.  Not sure if the 7D is overkill for my needs.  I'm also looking at the EF 24-70mm f/2.8L USM lens to be my new workhorse but I'm concerned that it may not be wide enough on an APS-C body and the lack of IS might be an issue.  There's also the EF 70-200mm f/2.8L IS II USM but I'm thinking it wouldn't be wise to spend all my budget on that lens right now (or maybe not?). When I install Selenium I get the following error:  Shubham@Shubham-To-be-filled-by-O-E-M:~$ sudo apt-get update     Get:1 http://security.ubuntu.com/ubuntu xenial-security InRelease [107 kB]     Hit:2 https://repo.skype.com/deb stable InRelease                            Hit:3 http://in.archive.ubuntu.com/ubuntu xenial InRelease                          Get:4 http://in.archive.ubuntu.com/ubuntu xenial-updates InRelease [109 kB]     Get:5 http://in.archive.ubuntu.com/ubuntu xenial-backports InRelease [107 kB]       Fetched 323 kB in 8s (38.6 kB/s)                                                    Reading package lists... Done     Shubham@Shubham-To-be-filled-by-O-E-M:~$ sudo pip install selenium     Traceback (most recent call last):       File "/usr/bin/pip", line 9, in &lt;module&gt;         from pip import main     ImportError: cannot import name main   How should I proceed? Say I want a random 1024-bit prime $p$.  The obviously-correct way to do this is select a random 1024-bit number and test its primality with the usual well-known tests.  But suppose instead that I do this:   select random odd 1024-bit number $n$ if $n$ is prime, return $n$ $n \leftarrow n+2$ goto 2   (This approach allows faster selection of primes via sieving.)  Since primes are not uniformly distributed on the number line, it would seem that this algorithm prefers primes that lie after long runs of composites.  Take a piece of the number line around $2^{1024}$ with x denoting a prime:     ---x-x----------------------------x------------------------x---x   Clearly our algorithm above is much more likely to find the 3rd prime above than to find the 2nd one.  Question: Is this a problem? I recently discovered that my computer is 64-bit. I have backed up my Home folder, and reinstalled Ubuntu. The reinstall wasn't nearly as painful as I thought. There is one thing that I can't quite seem to figure out: how do I get the 64-bit Firefox Beta build? I always get the Beta builds, but I want to take advantage of the 64-bit architecture of my computer.  says that Mozilla has come out with a 64-bit version of Firefox, but I can't seem to find it.  I do understand  of using a 64-bit browser, but I've decided to jump right in and do it anyway. (Flash and Java are already 64-bit, and who cares about Silverlight, since it's not for Linux anyway?)  There's only one issue, and it's a big one: I can't find the 64-bit Beta PPA!!! (I really hate using .tar.gz files, but I'd be willing to do that as long as I could still access Firefox via the Launcher. Oh, speaking of which, I don't understand .tar.gz files. Once, I managed to run one (the Dropbox Beta build,) but I have no idea whatsoever on how to install them: as in, click on the icon and go.) I am trying to sniff on a custom SPI-like bus protocol, which uses a unified bidirectional data line instead of separate MISO/MOSI. To make sense of the communication, I need to split it up into unidirectional lines before feeding them to my logic analyzer. Otherwise I wouldn't be able to see which device is responsible for which part of the signal. Since my devices won't talk to each other unless the protocol is carried out correctly, it's obvious that the bus splitting device has to be transparent to the actual agents communicating.  I tried to construct a bus splitting device, but failed as described . Since this question was maybe too specific and has not been answered, I want to ask more generally: Is there a bidirectional bus splitter that is able to split  into four wire SPI? Where could I buy such a device? (This seems similar to  question, only that I'm not talking about two really different protocols, so the answer does not apply). In principle only getting one direction would also suffice, since I could just subtract it from the full signal in order to retrieve the other half. And I'm also only interested in the master side of the communication.    The  seems to be a good candidate. Although it's advertised for use with I2C, it seems to be agnostic to the actual protocol on the lines. (As it does not even differentiate between DATA and CLOCK line for I2C.)     Splits I2C-bus signal into pairs of forward/reverse Tx/Rx, Ty/Ry signals for interface with opto-electrical isolators and similar devices that need unidirectional input and output signal paths.   As my devices operate on SPI mode 3 (polarity 1, idling on HIGH), the implementation of the receive pin should work:        sense the voltage state of the I2C-bus pin Sx (or Sy) and transmit this state to the pinTx (Ty respectively), and   sense the state of the pin Rx (Ry) and pull the I2C-bus pin LOW whenever Rx (Ry) is LOW.      But I am still puzzled on how this would actually work in sniffing this bidirectional bus. I could connect one device with the I2C line and grab its MOSI at Tx and MISO at Rx, but I would eventually have to connect both lines before feeding it to the other device, therefore making it impossible to separate the signals at my logic analyzer again. How can I connect the Tx/Rx for the slave while still being able to read them separately with a third device?  Edit: I now think this is actually not helping at all, since it leaves me with the same splitting issue as with out the device. I already have separate master and slave lines, I just don't know how to join them while still retrieving the separate directions.    I also stumbled upon the . It seems like this is a device designed for sniffing on buses, but I don't think it can help me in my case. Is there a mode where I can use it as a bridge on a bidirectional line and grab unidirectional signals off of it simultaneously?    Edit: I found this  which seems related to the issue. This does supposedly split the bidirectional line to feed it to two unidirectional isolators. The question is: Does this work for my setup? It describes the I2C lines being open-drain, whereas my lines are open-collector and also I'm not entirely sure if I could just leave out the isolator part and grab the signals from the lines or if these would have to be also hooked up to some transistor or be pulled high. Is LAN with StarCraft 2 definitely not possible? Easy curves in TikZ I find myself needing to draw lots of elegantly curved paths in TikZ. Ideally, I'd just specify a series of points, and TikZ would calculate the extra data itself to draw a nice series of curves passing smoothly through these points, perhaps with an optional "looseness" parameter that I could specify. But the only way I can find to draw nice curves is by explicitly giving control points, or by manually specifying in and out angles.  I can think up a simple algorithm to do this, which would certainly be within TikZ's power to perform: just choose the in and out angles in a simple fashion based on the relative angles between each adjacent pair of line segments.  Is something like this already built-in? Or can someone cook something up that does the job?  Edit: Jake has provided an answer using the plot [smooth] functionality. This is almost perfect! But it can't do what I need, because it doesn't let me specify tangent angles manually where needed, which is especially important at the beginning and end of the curve. I would have thought this would be a natural and straightforward addition to the existing plot [smooth] algorithm: for every coordinate, an optional angle should be able to be specified as an argument, which if supplied is treated as the tangent angle for the curve at that point. And while we're at it, it wouldn't hurt to also allow the tension to be modified along the path.  A minimal extension to the algorithm would just accept two optional parameters, for the curve tangent at the beginning and end. Why aren't my turtles breeding? Singular or plural following a list Cannot connect to internet after using airmon-ng check kill In new version of Kali 2.0 with updated "aircrack-ng" tool, there is a problem between Internet connection and using cracking tools.   I have my wireless card as wlan0. And the Internet connection is fine too. Then, what I do is:  airmon-ng start wlan0 airodump-ng wlan0mon   Now the airodump-ng doesn't work, saying "Device or resource busy".  In order to run this I have to kill some processes, using:  airmon-ng stop wlan0 airmon-ng check kill airmon-ng start wlan0 airodump-ng wlan0mon   Now the cracking process is up.   I can start cracking, but now I cannot connect to the Internet after the kill process.  On typing iwconfig in terminal, I get this:  root@kali:~#iwconfig wlan0mon IEEE 802.11bgn  ESSID:"myessid"         Mode:Managed  Frequency:2.412 GHz  Access Point: 00:00:00:00:00:00          Bit Rate=108 Mb/s   Tx-Power=20 dBm          Retry short limit:7   RTS thr:off   Fragment thr:off       Encryption key:off       Power Management:off       Link Quality=42/70  Signal level=-68 dBm         Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0       Tx excessive retries:2  Invalid misc:9   Missed beacon:0  eth0      no wireless extensions. lo        no wireless extensions.   And, on running ifconfig on terminal, I get this:  root@kali:~#ifconfig lo        Link encap:Local Loopback         inet addr:127.0.0.1  Mask:255.0.0.0       inet6 addr: ::1/128 Scope:Host       UP LOOPBACK RUNNING  MTU:65536  Metric:1       RX packets:5604 errors:0 dropped:0 overruns:0 frame:0       TX packets:5604 errors:0 dropped:0 overruns:0 carrier:0       collisions:0 txqueuelen:0        RX bytes:452904 (442.2 KiB)  TX bytes:452904 (442.2 KiB)   There is no wlan0 or wlan0mon. I also restarted the network manager by:      service network-manager restart   But nothing changed. Though it displays wlan0 when checked using ifconfig this time. If a PIC MCU provides multiple Vdd/Vss should you provide power to them all? Take a look at this example schematic:  The chip in question is the  and as you can see power is provided on both sides (with a 100nF cap to smooth noise I guess). Is this strictly required or could you put power into one side and just ignore the other? I know that I have just put power in one side and everything still seems to work fine but I feel uneasy with doing that. I feel that they would not waste pins that could be doing something useful by having an extra pair of power in/out pins. For what purpose does this PIC MCU (and others like it) have multiple power pins? Story about a time-traveler living backwards in a capsule I'm hunting for the title of a short story where a senile old man appears in a capsule in a laboratory.  They eventually realize time is passing backwards for him. After years he helps them build the machine he's in, and he changes places with the him that has been aging normally in the timeline. How long is a 'block'? Why does node not evaluate Math.tan(Math.PI/2) to Infinity but Chrome V8 does?