When I'm working on some remote host via SSH, I often need to upload or download files.  With my current setup, I need to switch to another terminal and conjure up rsync or sftp, which can be a pain if the target host isn't registered in DNS (need to copy+paste IP address) or if I'm working in a directory a few levels down (need to re-type the whole path).  Is there a command-line tool that combines SSH and SFTP?  Ideally, it would start a remote shell like normal SSH does but at the press of some key combination, it would switch to an SFTP prompt allowing me to up- download files from the directory the shell is currently in.
If I'm logged in to a system via SSH, is there a way to copy a file back to my local system without firing up another terminal or screen session and doing scp or something similar or without doing SSH from the remote system back to the local system?
Finding the limit of $(1-\cos x)/x^2$ $$\lim _{x \to 0}{1-\cos x\over x^2}={2\sin^2\left(\frac{x}{2}\right)\over x^2}={\frac{2}{x^2}\cdot {\sin^2\left(\frac{x}{2}\right)\over \left(\frac{x}{2}\right)^2}}\cdot\left(\frac{x}{2}\right)^2$$  now $$\lim_{x \to 0}{\sin^2\left(\frac{x}{2}\right)\over \left(\frac{x}{2}\right)^2}=\left({\sin\left(\frac{x}{2}\right)\over \left(\frac{x}{2}\right)}\right)^2=1^2$$  So we have $$\frac{2}{x^2}\cdot \left(\frac{x}{2}\right)^2=\frac{2}{x^2}\cdot \left(\frac{x^2}{4}\right)=\frac{1}{2}$$  Are the moves right? singular/ plural in the attributive A doll house or a dolls house? Which is correct for the toy? ... There's that thing called Same Sex Couples Act; how about calling it Same Sex Couple Act?  The question is - when should I put attributives in plural? As far as I remember, Bill Bryson claimed in his Dictionary of Troublesome Words that - and that's what I vaguely recall from my classes - attributives should be in singular. Except for some exceptions. If so, what are they? I'm looking for some rule of thumb here other than "when in doubt, JFGI", of course.  NOTE: I leave out forms like a doll's house/dolls' house as they're pretty clear to me, as well as cases like The 'Big Boys and Their Motors' Club in which attributives are separate entities. How can we run a command stored in a variable? $ ls -l /tmp/test/my\ dir/ total 0   I was wondering why the following ways to run the above command fail or succeed?  $ abc='ls -l "/tmp/test/my dir"'  $ $abc ls: cannot access '"/tmp/test/my': No such file or directory ls: cannot access 'dir"': No such file or directory  $ "$abc" bash: ls -l "/tmp/test/my dir": No such file or directory  $ bash -c $abc 'my dir'  $ bash -c "$abc" total 0  $ eval $abc total 0  $ eval "$abc" total 0 sqlite3: not found Intersection of two lists in Bash The Density of Clouds Isomorphism between $\mathfrak o(4,\mathbb R)$ and $\mathfrak o (3,\mathbb R) \oplus\mathfrak o (3,\mathbb R) $ I am registered on about 80 SE sites, am an "avid user"(>200 rep) on about 30, and a modest user (103-199 rep) on about 20 more.  Once when I tried to ask a question on Open Data (my "new user" site), the "systemwide" 40 minute rate limit kicked in. So I asked on meta , given that my previous post on the site was days ago. So a mod commented by telling me about the systemwide post rule and asking me if I had just come from another site. I said, yes, History (my best site, 40K rep.)  I can see why I would be rate limited on Open Data. I can understand that I would be rate limited if I had come from say, Open Source, another site where I'm a new user. But did the system "rate limit" me as a new user on one site, based on my activity on History, an "established" site?  Also, about the one day new user rate limit after a question is downvoted: Suppose a question on the previous site receives two upvotes and one downvote (net of one upvote). Is that a different situation than receiving one down downvote and no upvotes? Or does the downvote count in both cases, including the one where there were offsetting upvotes? How about if the downvoted question on the previous site was deleted?  I don't have this problem when going from one "established" (greater than 125 rep) site to another. I understand why a person would be "rate limited" going from one new site to another; SE wants people to ask questions 40 minutes apart on their new sites. In my case, I was blocked when I left an "established" site (my best) to go to a new site, which is almost the same as going to a new site de novo.  Why would this be? Or can't the system tell that my "first" site was an established site? Would I have been similarly rate limited if I went first to the "new" site, and 39 minutes later to the established site? Or does the rate limit apply only when the "destination" site is the new site?  Put another way, there are four permutations of established and new sites: 1) established to established 2) new to new 3) established to new and 4) new to established. The block doesn't apply in the first case, does apply in the second case, and apparently applies in the third. What about the fourth? And why? Because it is not "uniform" across sites in the four cases.   Edit: Unlike the other question, this one is not about the general rule. It is about the "special case" described in the paragraph above. Validation Rule on picklist under opportunities There are 2 requirements:    standard users can’t update the status of a record beyond “open won” (so that only SF Admins or auto processes update “registered” and the stages beyond registration. Validation rule for this:    ~   AND(       $Profile.Name &lt;&gt; "System Administrator",      ISCHANGED(StageName),      OR(TEXT(StageName) = "Registered",     TEXT(StageName) = "Pre-Certified",     TEXT(StageName) = "Documentation, Submission",     TEXT(StageName) = "Performance verified",     TEXT(StageName) = "Appeals",     TEXT(StageName) = "Certification/ Closed Won")      )   Requirement 2: Standard users cannot update the status of a record that is already Registered (or post-registered phase). For us, some Opp was already “Registered” but some standard user  was able to change the record to “Open Won.”    I am looking for the validation rule of requirement 2 and which should align with first requirement also.  Thanks, Please guide. Find $n$ such that $n/2$ is a square, $n/3$ is a cube, and $n/5$ a fifth power Calculate mean of ordinal variable I've read in a number of places that calculating the mean of an ordinal variable is inappropriate. I'm trying to get an intuition for why it might be inappropriate. I think it is because, in general, an ordinal variable is not normally distributed and so calculating the mean will give an inaccurate representation. Could somebody give more detailed reasoning for why calculating the mean of an ordinal variable might be inappropriate? I ran into an interesting behavior recently.  It seems that if I override .equals() to take a parameter other than Object, it doesn't get called.  Can anyone explain to me why this is happening?  It seems to violate my understanding of polymorphism in OOP, but maybe I'm missing something.  Here's much simpler code that shows what I'm seeing:  public class MyClass {   private int x;   public MyClass(int n) { x = n; }   public boolean equals(Object o) { return false; }   public boolean equals(MyClass mc) { return x == mc.x; }   public static void main(String[] args) {     List&lt;MyClass&gt; list = new ArrayList&lt;MyClass&gt;();     list.add(new MyClass(3));     System.out.println("Contains 3? " + list.contains(new MyClass(3)));   } }   When this is run, it prints "Contains 3? false".  It looks like the equals(Object) function is called, even though there is another that would work.  By contrast, if I write equals like this the code works as expected:  public boolean equals(Object o) {   if(!(o instanceof MyClass))     return false;   MyClass mc = (MyClass)o;   return x == mc.x; }   Why isn't it figuring out which version of the function to call based on the type of the parameter? "Mutable variable is accessible from closure" in a function passed to Array.prototype.every CSS Transform Skew If virtual particles sometimes add more mass/energy to a system then was inputed or comes out in the output, how do they not violate conservation of mass/energy. Why didn't Palpatine publicly change his name once he became Emperor? Anakin Skywalker was known as Darth Vader (this was already his Sith name) after the creation of the Galactic Empire.  So why did Palpatine remain "Emperor Palpatine"? Why didn't he embrace his persona as Darth Sidious?  I started wondering after reading one of the answers to How to get div height to auto-adjust to background size? How do I get a div to automatically adjust to the size of the background I set for it without setting a specific height (or min-height) for it? Convert HTML to PDF in .NET I want to generate a PDF by passing HTML contents to a function. I have made use of iTextSharp for this but it does not perform well when it encounters tables and the layout just gets messy.  Is there a better way? Unique constraint that allows empty values in MySQL Can a university revoke one's degree for his minor misconduct?