Style bug, for comments tab in user profile in Chrome
Selecting text in profile activity comments causes unexpected clipping
Export iMessages in human readable form for archival I have a long (several months' worth) iMessage conversation with a contact.  He lost these messages when he re-installed his OS, but I still have the archive.  There is some important information there that we'd like to keep.  Is there a simple way to export this conversation for archival in a human readable form, and also keep any images?  I can select parts of the conversation, copy it to the clipboard and paste it into a rich text document, but this discards all images.  I'm looking for a way that keeps the images.  Note: I use iMessage on OS X only, not iOS.  (Ideally I'd also like to export all non-image file attachments, but I'm not expecting that this will be possible.) Stopping users voting multiple times on a website I'm planning to add some vote up/vote down buttons to a website I run. This seems easy enough but I want to stop people voting multiple times. One solution would be to make them register before allowing them to vote but I'd prefer not to have to force them to register.   Is there are a reasonably straightforward way of doing this? Checking the IP address doesn't seem like a good solution, since it's possible that multiple users may come from the same IP address.   Cookies might be the answer, but a savvy user could delete the cookie. Any better ideas? + or @ mark after running 'ls -al' In Mac OS X, run 'ls -al' gives me something like this.   drwxrwxrwx+  4 smcho  staff     136 May  5 09:18 Public drwxr-xr-x+  6 smcho  staff     204 Feb  1  2010 Sites drwxrwxrwx   9 smcho  staff     306 Feb  2  2010 backup drwxr-xr-x@ 36 smcho  staff    1224 Sep  4 22:51 bin    What's the + or @ at the end of the first column means? Is this unique to Mac, or common in UNIX?   ADDED  After Michael Mrozek's answer, I ran 'ls -ale' to get the following.   drwx------+ 66 smcho  staff    2244 Aug 30 13:40 Library  0: group:com.apple.sharepoint.group.3 allow search  1: group:everyone deny delete drwxr-xr-x   3 smcho  staff     102 Sep  4 15:01 Mail drwx------+ 13 smcho  staff     442 Aug 28 17:55 Movies  0: group:everyone deny delete drwx------+  6 smcho  staff     204 Jul  9 09:37 Music  0: group:everyone deny delete drwx------+ 11 smcho  staff     374 Aug 28 16:55 Pictures  0: group:everyone deny delete drwxr-xr-x   3 smcho  staff     102 Mar 18 15:43 Projects drwxrwxrwx+  4 smcho  staff     136 May  5 09:18 Public  0: group:everyone deny delete drwxr-xr-x+  6 smcho  staff     204 Feb  1  2010 Sites  0: group:everyone deny delete   What those appended messages mean? Why do I have them for some of the files? I don't remember doing anything particular for them. Several lines of formulas to the left of one curly brace pointing to equation number How to make several lines of equations under one curly brace from the left side, such that it point to a reference number.  Now I do something like this:  \begin{align} \left. \begin{array}{ll} a = b + c \\ &amp; \dots  \\ a = b + c \\ &amp; \dots  \\ a = b + c  \end{array} \right\} \label{formulas}\\ \end{align}   But equation number appears in the bottom of curly brace. Should the first word after a colon be capitalized? Which of the following is correct?   For example: This. For example: this. I'm looking for the fastest way to determine if a long value is a perfect square (i.e. its square root is another integer):    I've done it the easy way, by using the built-in  function, but I'm wondering if there is a way to do it faster by restricting yourself to integer-only domain. Maintaining a lookup table is impractical (since there are about 231.5 integers whose square is less than 263).   Here is the very simple and straightforward way I'm doing it now:  public final static boolean isPerfectSquare(long n) {   if (n &lt; 0)     return false;    long tst = (long)(Math.sqrt(n) + 0.5);   return tst*tst == n; }   Note: I'm using this function in many  problems.  So no one else will ever have to maintain this code.  And this kind of micro-optimization could actually make a difference, since part of the challenge is to do every algorithm in less than a minute, and this function will need to be called millions of times in some problems.    I've tried the different solutions to the problem:   After exhaustive testing, I found that adding 0.5 to the result of Math.sqrt() is not necessary, at least not on my machine. The  was faster, but it gave incorrect results for n >= 410881.  However, as suggested by , we can use the FISR hack for n &lt; 410881. Newton's method was a good bit slower than Math.sqrt().  This is probably because Math.sqrt() uses something similar to Newton's Method, but implemented in the hardware so it's much faster than in Java.  Also, Newton's Method still required use of doubles. A modified Newton's method, which used a few tricks so that only integer math was involved, required some hacks to avoid overflow (I want this function to work with all positive 64-bit signed integers), and it was still slower than Math.sqrt(). Binary chop was even slower.  This makes sense because the binary chop will on average require 16 passes to find the square root of a 64-bit number. According to John's tests, using or statements is faster in C++ than using a switch, but in Java and C# there appears to be no difference between or and switch. I also tried making a lookup table (as a private static array of 64 boolean values).  Then instead of either switch or or statement, I would just say if(lookup[(int)(n&amp;0x3F)]) { test } else return false;.  To my surprise, this was (just slightly) slower. This is because . Who can use magic scrolls? I'm confused about who can use scrolls in 5e. In the DMG, p139 under Magic Item Categories: Scrolls, it states that:     Any creature that can understand a written language can read the   arcane script on a scroll and attempt to activate it.   This implies that anyone can try to cast a spell using a scroll. However, on p.200 in the Spell Scroll entry it states that:     If the spell is on your class's spell list, you can use an action to read the scroll and cast its spell without having to provide any of the spell's components. Otherwise, the scroll is unintelligible.   Then there is the bit about a DC 10 + scroll spell level ability check if the spell is higher than a spell slot that you can cast.     If the spell is on your class's spell list but of a higher level than you can normally cast, you must make an ability check using your spellcasting ability to determine whether you cast it successfully. The DC equals 10 + spell's level. On a failed check, the spell disappears from the scroll with no other effect.    So, which is it? Can anyone who can read a language use a scroll (like a fighter) if they make an arcana check, or just a PC with that specific spell in their spell list (only spell casters)? Find a recurrence relation for the number of ways to arrange $n$ dominoes to fill a $2$ by $n$ checkerboard. I am having trouble with this question, please take a look at it:     Find a recurrence relation for the number of ways to arrange $n$ dominoes to fill a $2$ by $n$ checkerboard.   I have just started reading the topic and it is one of the starting problem. Please help. You can give me some hints, a complete answer is also appreciated.  Thanks In follow up to , it appears that some numbers cannot be represented by floating point at all, and instead are approximated.  How are floating point numbers stored?  Is there a common standard for the different sizes?  What kind of gotchas do I need to watch out for if I use floating point?  Are they cross-language compatible (ie, what conversions do I need to deal with to send a floating point number from a python program to a C program over TCP/IP)? Feedback for The Loop - May 2020 May’s “The Loop” blog post was just posted, you can read it . A popular response last month to our post about how we receive, prioritize and implement feedback was a question around how this framework gets utilized in the practical sense. We thought that Dark Mode was a great feature to dig down into as it was so widely requested and anticipated.   We hope you enjoy this month’s post, please leave any questions or comments you have in this thread and we will respond ASAP. Why is apt-get always using proxy, although no proxy is configured? Transparent model when exporting fbx file to Unity So I have this shark model which I animated and ready to export it on fbx and transport it to Unity.  But When I put it on Unity, It looks transparent like this.    Many of the solutions online say that the problem is because of my faces, and they told me to recalculate it or something, but normals are just fine. Is there any other solution?  here's the blend file: Invalid signature for Kali Linux repositories : "The following signatures were invalid: EXPKEYSIG ED444FF07D8D0BF6 Kali Linux Repository" How do I eliminate reflection on glass? When I take a picture through a window, I often see a reflection on the glass. I have noticed that this occurs mostly when it is dark or overcast outside or it is especially bright on my side of the glass. How can I stop this? Apt-get stuck at 0% [Working] Under what assumptions can a semigroup $(S,*)$ be embedded into a group? How does a credit card company make any money off of me using their card if there are no fees associated with the card (I don't pay any extra) and I pay off my balance on time every month (so I don't pay any fees ever for this either).  Are they just banking on the fact that many people don't do this and end up owing them money? I'm no expert in darkroom photography, but it seems a little odd that there is a type of light that doesn't affect film or developing paper etc. The only way that I could think to explain it is:   The low frequency red photons don't have enough energy to raise electron states in the film/paper, or Magic   either way, I'm curious to know how this handy tool is, as per title, safe. Can I convert a string representing a boolean value (e.g., 'true', 'false') into a intrinsic type in JavaScript?  I have a hidden form in HTML that is updated based upon a user's selection within a list. This form contains some fields which represent boolean values and are dynamically populated with an intrinsic boolean value. However, once this value is placed into the hidden input field it becomes a string.  The only way I could find to determine the field's boolean value, once it was converted into a string, was to depend upon the literal value of its string representation.  var myValue = document.myForm.IS_TRUE.value; var isTrueSet = myValue == 'true';   Is there a better way to accomplish this? Find a file when you know its checksum?