I was playing around a bit with the names of some executables, putting them in a folder, ~/bin, which is in my $PATH. Now I'm wondering how I can set the preferences of a bash-3.2 terminal so that it picks up these executables instead of the builtins or aliases to execute.  For example, if I put a script named cd in a directory in $PATH, the builtin for cd is still executed. However, if I create an alias for cd, then this alias will be executed, overriding the builtin.  $ type cd cd is a shell builtin   My questions   Is there a way to make an executable file in $PATH have, by default, preference over a shell builtin, by executing only, e.g. cd without having to resort to using the commands builtin or command? I'm also interested in any official reference which discusses this preference (not the reasoning, that I do understand).   Note: This question is purely for personal educational purposes, I am wondering why it works the way it works.
When trying to add a bit more detail to a related , I realized I don't know how to specify which one of the available Bash word types to execute. According to help type there are five word types:   alias keyword function builtin file   It's possible for a word to have several types (true is just an example; a more commonly overridden word would be cd):  $ type -a true true is a shell builtin true is /bin/true   How do you force the execution of a specific synonym? So far, in order of precedence:   alias: This is a special case since it has precedence over all the other synonyms. Forcing this would only be useful when the command should fail if the alias is not defined.  $   keyword:  $   function:  $   builtin:  $ builtin true  file:  $ command true $ $(which true) $ /bin/true    :   Quoting a word excludes aliases and keywords. That is,  $ 'true'   will run only the function, builtin or file.
How to debug suspend? If $e^{itx_n}$ converges for every $t\in\mathbb R$, then does $x_n$ converge? iPhone 6s with iOS 12.4 not connecting to MacBook Pro mid2015 with macOS 10.14.6 Height of Water 'Splashing' Suppose from a height $H$, I throw a ball of mass $M$ and radius $R$ with initial velocity $u$ into a pool of depth $x$ having a liquid with density $\rho$ and coefficient of viscosity $\eta$.  Upto what height will the Water Splash?   This may be a silly question! (Source : my brain) Assume every condition to be identical with no air resistance. Feel free to assume any other parameters if needed.  P.S. $\rightarrow$ I've see similar questions but some of them want an exact answer and some are not so direct while some are incomplete questions...  Small Note : We do not have to consider the highest 'single' drop... Just assuming almost every water droplet jumped upto a height $h$. Ideal conditions...  Feel free to assume the liquid as WATER if required! What are PATH and other environment variables, and how can I set or use them? Questions about    setting environment variables the PATH   are very common here, and in most cases the answers are very similar to each other. In the future it would be nice to have a good Q/A for this.  So the question is: What are environment variables, like the executable PATH, and how can I change and use them on major operating systems?  A good answer would include a simple explanation of what environment variables and especially PATH mean to the OS, as well as simple guidelines on how to set and read them accordingly. How to schedule jobs in Sql server 2008 for less than 10 sec? I want to run a job every 3 seconds, however in SQL Server 2008 we cannot define an interval of less than 10 seconds.  The job is used to insert/update visitor information, and segmentation information into a database which is tracked by google search.   There are up to about 100 rows inserted in a 2 or 3 seconds. That job inserts and update the table in a database. Is there any way to schedule it using sp job scheduling configuration? Prove that if $g^2=e$ for all $g$ in $G$ then $G$ is Abelian. Prove that if $g^2=e$ for all $g$ in $G$ then $G$ is Abelian.   This question is from group theory in Abstract Algebra and no matter how many times my lecturer teaches it for some reason I can't seem to crack it.   (Please note that $e$ in the question is the group's identity.)  Here's my attempt though...  First I understand Abelian means that if $g_1$ and $g_2$ are elements of a group $G$ then they are Abelian if $g_1g_2=g_2g_1$...  So, I begin by trying to play around with the elements of the group based on their definition...  $$(g_2g_1)^r=e$$  $$(g_2g_1g_2g_2^{-1})^r=e$$ $$(g_2g_1g_2g_2^{-1}g_2g_1g_2g_2^{-1}...g_2g_1g_2g_2^{-1})=e$$  I assume that the $g_2^{-1}$'s and the $g_2$'s cancel out so that we end up with something like,  $$g_2(g_1g_2)^rg_2^{-1}=e$$ $$g_2^{-1}g_2(g_1g_2)^r=g_2^{-1}g_2$$  Then ultimately...  $$g_1g_2=e$$  I figure this is the answer. But I'm not totally sure. I always feel like I do too much in the pursuit of an answer when there's a simpler way.  Reference: Fraleigh p. 49 Question 4.38 in A First Course in Abstract Algebra. Survival probability up to time $n$ in a branching process. Let $\{Z_n : n=0,1,2,\ldots\}$ be a Galton-Watson branching process with time-homogeneous offspring distribution $$\mathbb P(Z_{n,j} = 0) = 1-p = 1 - \mathbb P(Z_{n,j}=2), $$ where $0&lt;p&lt;1$. That is, $Z_0 = 1$ and $$Z_n = \sum_{j=1}^{Z_{n-1}}Z_{n,j}$$ for $n\geqslant 1$. Let  $$T=\inf\{n : Z_n=0\} $$ be the extinction time of the process. I want to find $$t_n := \mathbb P(T&gt;n), $$ i.e. the probability that the process survives up to time $n$. I found the following recurrence:  $$t_{n+1} = p(2t_n - t_n^2)$$ (with $t_0=1$) from this mathoverflow question:   I checked the recurrence for small values of $n$, and confirmed that $t:=\lim_{n\to\infty} t_n$ satisfies $$ t = p(2t - t^2),$$ both in the case where $t=0$ $\left(p\leqslant\frac12\right)$ and where $t=2-\frac1p$ $\left(p&gt;\frac12\right)$. So I'm fairly confident this recurrence is valid. However, I have no idea how to solve it.  For context, this problem comes from Adventures in Stochastic Processes by Sidney Resnick:   From @Did's comment, it appears to be intractable to find a closed form for $\mathbb P(T&gt;n)$. I find it curious that the question would be asked were it not, though. Proof of $(\mathbb{Z}/m\mathbb{Z}) \otimes_\mathbb{Z} (\mathbb{Z} / n \mathbb{Z}) \cong \mathbb{Z}/ \gcd(m,n)\mathbb{Z}$ How to install GUI desktop on a server? After installing Ubuntu server how do I install the desktop environment? Kubuntu - can not enter wifi credentials after adding external wifi card My ethernet connection is quite unreliable (It uses powerline adapters) so I bought an external wifi adapter. I have plugged it in and run the command sudo ip address add 192.168.0.39/24 brd + dev enp7s0, and KDE has detected it. Unfortunately, it doesn't seem to realise it is a wireless network and therefore needs credentials. Where I could normally find a place to enter credentials (the network widget, system settings) there are none. KDE reports that the device is connected in the UI. How do I make it work out that it is wireless and therefore needs credentials? Edit: With ethernet plugged out, (USB) adapter plugged in: $ ip address show 1: lo: &lt;LOOPBACK,UP,LOWER_UP&gt; mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo        valid_lft forever preferred_lft forever     inet6 ::1/128 scope host         valid_lft forever preferred_lft forever 2: enp7s0: &lt;NO-CARRIER,BROADCAST,MULTICAST,UP&gt; mtu 1500 qdisc fq_codel state DOWN group default qlen 1000     link/ether 04:d9:f5:8a:f5:e0 brd ff:ff:ff:ff:ff:ff  With ethernet plugged in, adapter plugged in: 1: lo: &lt;LOOPBACK,UP,LOWER_UP&gt; mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo        valid_lft forever preferred_lft forever     inet6 ::1/128 scope host         valid_lft forever preferred_lft forever 2: enp7s0: &lt;BROADCAST,MULTICAST,UP,LOWER_UP&gt; mtu 1500 qdisc fq_codel state UP group default qlen 1000     link/ether 04:d9:f5:8a:f5:e0 brd ff:ff:ff:ff:ff:ff     inet 192.168.0.51/24 brd 192.168.0.255 scope global dynamic noprefixroute enp7s0        valid_lft 863988sec preferred_lft 863988sec     inet6 fe80::7eb1:eca2:96a0:fe5c/64 scope link noprefixroute         valid_lft forever preferred_lft forever  With just ethernet: 1: lo: &lt;LOOPBACK,UP,LOWER_UP&gt; mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo        valid_lft forever preferred_lft forever     inet6 ::1/128 scope host         valid_lft forever preferred_lft forever 2: enp7s0: &lt;BROADCAST,MULTICAST,UP,LOWER_UP&gt; mtu 1500 qdisc fq_codel state UP group default qlen 1000     link/ether 04:d9:f5:8a:f5:e0 brd ff:ff:ff:ff:ff:ff     inet 192.168.0.51/24 brd 192.168.0.255 scope global dynamic noprefixroute enp7s0        valid_lft 863960sec preferred_lft 863960sec     inet6 fe80::7eb1:eca2:96a0:fe5c/64 scope link noprefixroute         valid_lft forever preferred_lft forever  With nothing: 1: lo: &lt;LOOPBACK,UP,LOWER_UP&gt; mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo        valid_lft forever preferred_lft forever     inet6 ::1/128 scope host         valid_lft forever preferred_lft forever 2: enp7s0: &lt;NO-CARRIER,BROADCAST,MULTICAST,UP&gt; mtu 1500 qdisc fq_codel state DOWN group default qlen 1000     link/ether 04:d9:f5:8a:f5:e0 brd ff:ff:ff:ff:ff:ff  lsusb, adapter plugged in: Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 003 Device 002: ID 046d:c31c Logitech, Inc. Keyboard K120 Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 003: ID 1d57:32da Xenta 2.4GHz Receiver (Keyboard and Mouse) Bus 001 Device 004: ID 0bda:b812 Realtek Semiconductor Corp. 802.11ac NIC Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub  I'm not adding it with it plugged out because it's obviously the Bus 001 Device 004: ID 0bda:b812 Realtek Semiconductor Corp. 802.11ac NIC. There were no restarts between any of these changes. How to convert milliseconds into human readable form? Why doesn't the Enterprise use stealth/invisibility technology like the Romulans and Klingons? The stealth mode of starships plays a huge role in many Star Trek films and episodes and is a strong advantage in combat. I remember an episode revealing that the Federation developed a secret stealth technology (afair on Riker's former ship with another captain appearing in this episode) that even made it possible to fly with the ship through matter.   Nonetheless, while stealth technology seems standard for Romulans, Klingons (Ferengi, Vulcans?) and does not break any intergalactic laws (do these exist at all?), the Federation doesn't use it? What is a Seaman's book, and can it really replace a passport? What is a "Seaman's book", and can it really replace a passport for some or all immigration purposes?  Even Wikipedia the all-knowing does not seem to know, although it contains many tantalizing references.  :     Seaman deserters may not have a passport but rather hold a Seaman's Book, (a national identity document issued to professional seamen that contains a record of their rank and service career).   :     Possession of one of the following documents is sufficient to demonstrate [right to abode] ...         Hong Kong Seaman's Identity Book How to read command line arguments of another process in C#? setTimeout and "this" in JavaScript I have a method that uses the  function and makes a call to another method. On initial load method 2 works fine. However, after the timeout, I get an error that says method2 is undefined. What am I doing wrong here?  ex:  test.prototype.method = function() {     //method2 returns image based on the id passed     this.method2('useSomeElement').src = "http://www.some.url";     timeDelay = window.setTimeout(this.method, 5000); };  test.prototype.method2 = function(name) {     for (var i = 0; i &lt; document.images.length; i++) {         if (document.images[i].id.indexOf(name) &gt; 1) {             return document.images[i];         }     } }; Blank screen after installing nvidia restricted driver What are the basic rules and idioms for operator overloading? I remember being taught that the correct order of adjectives in English was something along the lines of "Opinion-Size-Age-Color-Material-Purpose."  However, it's been a long time and I'm pretty sure I've forgotten a few categories (I think there were eight or nine). Can anyone fill them in? I believe I have solved a famous open problem. How do I convince people in the field that I am not a crank? I am interested in the situation where you have a very interesting result. For instance, you have solved a very important open problem. However, you are not known in the field and do not have any remarkable publications. Your supervisor thinks the work is good and you submit the work to a high profile journal, but you get rejected.  The thing is that the contribution is very strong. It breaks what most people believe or what they have already proven: e.g., you solve the P vs. NP problem or any other well known open problem.   The reviewers strongly reject your work with no justification and they do not state why the result is wrong. Examples of reviewer comments include:   "The proof must be wrong."  "You cannot achieve such a result."  "You do not understand well the notion of ..."   My question is what to do in this situation? Where to go? If your advisor accepts the work, but the reviewers from the top journal reject the work without even explaining the mistakes,  what should you do?