On the bash prompt one, three or more slashes (/,///,////, ...) are treated as a single slash, whereas two slashes (//) are left as is:  12:07 $ cd / 12:07 $ pwd / 12:07 $ cd // 12:07 $ pwd // 12:07 $ ls bin  boot  cdrom  dev  etc  home  initrd.img  lib  lib64  lost+found  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var  vmlinuz 12:07 $ cd /// 12:07 $ pwd / 12:07 $ ls bin  boot  cdrom  dev  etc  home  initrd.img  lib  lib64  lost+found  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var  vmlinuz   Usual suspects' versions:  12:07 $ bash --version GNU bash, version 4.3.11(1)-release (x86_64-pc-linux-gnu)  12:20 $ dpkg-query -s coreutils | grep Version Version: 8.21-1ubuntu5
I'm working on a python script that passes file locations to an scp subprocess. That's all fine, but I'm in a situation where I may end up concatenating a path with a filename such that there's a double '/ in the path. I know that bash doesn't care if you have multiple file separators, but I'm wondering how exactly that is rectified. Is it bash that strips extra /s or does it really not matter ever?  I ask because it will save me several lines of code to check for extra /s while concatenating. I know it's not a big deal, but I'm curious as well. I have a bash script that has the line cd //usr (instead of cd /usr), which seems to imply there might be a significance to using multiple /s in a path
$M= \{ A \in Mat_{2 \times 2}{\mathbb{R}}| \det(A)=1 \}$ is homeomorphic to $S^{1} \times \mathbb{R}^{2}$ Find all the numbers $n$ such that $\frac{4n-5}{60-12n}$ can't be reduced. A guy scammed me, but he gave me a bank account number & routing number. Can I use that to take out what he owes me? Sudden increase in timing when summing over 250 entries How can I reinstall GRUB to the EFI partition? Here is the dictionary I have  propertyList = {     "id":           "int",     "name":         "char(40)",      "team":         "int",     "realOwner":    "int",      "x":            "int",     "y":            "int",      "description":  "char(255)",      "port":         "bool",     "secret":       "bool",     "dead":         "bool",     "nomadic":      "bool",      "population":   "int",     "slaves":       "int", }   But when I print it out with "\n".join(myDict) I get this  name nomadic dead port realOwner secret slaves team y x population id description   I know that a dictionary is unordered but it comes out the same every time and I've no idea why. Is there a technical reason Android update story is so bad? Is there a technical reason why Android phones general lag a lot behind the stable released version of Android?    This applies to both new phones, for example a recent trip to the phone shop everything was 4.0 to 4.2.1, KitKat could not be seen. And also old phones, my girlfriend's iPhone 4 had an OTA update to the latest OS, this is a July 2010 phone, whilst a July 2010 Android is basically a paperweight.    Presumably Android itself doesn't concern itself with the actual hardware, and thus talks to the OS via abstractions? I guess then the handset maker just provides the drivers for the specific hardware, thus I can't see the issue with pushing OTA updates if the ABI remains stable (my phone doesn't grow new hardware features). When is "to" a preposition and when the infinitive marker? Putnam and Beyond AM-GM help Make bash exit != 0 when called by AWK and interrupted with ^C I'm having an issue with the following piece of (G)AWK script:  do {     ... } while (system("sleep 10"))   My intention is to break the loop when the user presses ^C during the sleep, but it's not working.  I believe the problem is that Bash exits with 0 when interrupted with ^C, at least when it's executed by AWK's system():  $ awk 'BEGIN { print "\n" system("sleep 2") }' (let the sleep complete) 0      $ awk 'BEGIN { print "\n" system("sleep 2") }' ^C 0   Why is it so?   Is this a bug in Bash or in (G)AWK?  Is there a simple solution that doesn't involve complicated Bash-specific syntax like trap?  The best I could come up with is this:  do {     ... } while (42 == system("sleep 10 &amp;&amp; exit 42"))   which still looks like a kludge to me. Access NSMutableArray from another class - Objective C Lets say I'm building a base class which will be extended upon by the children class. So a base class is called Base and children can be Child1, Child2, etc.  In the base class's constructor, how can i get the value of Child1/Child2?  This is all using PHP Let $G$ be a finite abelian group s.t. it contains a subgroup $H_{0} \neq (e)$ which lies in every subgroup $H \neq (e) $. Prove that $G$ must be cyclic.   Also what can be said about $o(G)$ ?    I'm clueless about this problem from Herstein. I tried to think $G$ might be a solvable group and its subgroups are all normal (as $G$ is abelian) . But I'm unable to get further. Let , $\Delta = B(0,1)$.  If $f:\Delta \rightarrow \Delta$ is holomorphic, and $f(0)=0$, prove that $|f(z)+f(-z)| \leq 2|z|^2$.  My attempt so far:  $\displaystyle f(z) = \sum_{n=0}^{+\infty} a_n z^n = \sum_{n=0}^{+\infty} a_{2n} z^{2n} + \sum_{n=0}^{+\infty} a_{2n+1} z^{2n+1}$  $\displaystyle f(-z) = \sum_{n=0}^{+\infty} a_n (-z)^n = \sum_{n=0}^{+\infty} a_{2n} z^{2n} - \sum_{n=0}^{+\infty} a_{2n+1} z^{2n+1}$  Then, $\displaystyle f(z)+f(-z) = 2  \sum_{n=0}^{+\infty} a_{2n} (z^2)^n =: 2 g(z^2)$  If $g(\Delta) \subset \Delta$, as $g(0) = 0$, I can invoke Schwarz Lemma and I win. However, I don't know how to prove this. Could anyone help me? Thanks! I'm trying to create globally-unique identifiers in JavaScript.  I'm not sure what routines are available on all browsers, how &quot;random&quot; and seeded the built-in random number generator is, etc. The GUID / UUID should be at least 32 characters and should stay in the ASCII range to avoid trouble when passing them around. I have this new problem since 2014 begin. I cant remotely login to this enterprise network for giving them support. Its keep showing this new error.  How to fix it please?    EDIT: Light Presets .exr I would like to install light presets for Blender to automate my lightning in my scenes. I have some .exr files (from Greyscalegorilla) but I don't know how to do it on Blender to make it work. Can someone help me? Thank you How to install Wi-Fi driver for Realtek RTL8821CE on Ubuntu 18.04? Commuting: How to carry office clothing so it doesn't get crushed? I have the bike, I have the best route; but now I want to know, how do I transport my clothing in each day? I typically wear suit pants and a business shirt, but not a suit jacket.   Am I better off leaving my clothes at work, or is there a special bag that would let me carry in shirt/pants without them getting crushed? Why are Only Real Things Measurable? Why can't we measure imaginary numbers? I mean, we can take the projection of a complex wave to be the "viewable" part, so why are imaginary numbers given this immeasurable descriptor? Namely with operators in quantum mechanics, why must measurable quantities be Hermitian, and consequently real?