I am attempting to run this find command to match files with a camelcased name, with the goal being to put a space between adjacent lower and upper case letters, but it's not matching anything:  find -E . -regex "([a-z])([A-Z])"   An example of a file I'm trying to match is  ./250 - ErosPhiliaAgape.mp3   I've tested this regex on this file  and it matches successfully.  What is it I'm doing wrong with my find command?
I wrote a regular expression which works well in a certain program (grep, sed, awk, perl, python, ruby, ksh, bash, zsh, find, emacs, vi, vim, gedit, …). But when I use it in a different program (or on a different unix variant), it stops matching. Why?
I found this pretty good small research, but I am still concerned about "regular usage" in life, say, when I am talking in the office, especially because of this comment:     To me: Stone is something you can pick up with one hand (for   throwing). A rock takes two hands. Direct product of abelian groups Let $G_1,\dots,G_n$ be groups. Prove that the direct product $G_1\times\cdots\times G_n$ is abelian if, and only if, each of $G_1,\dots,G_n$ is abelian. To prove that the direct product is abelian is straightforward but what I don't understand is the converse. How do you declare an interface in C++? Can anyone provide some pseudo code for a roulette selection function? How would I implement this:    I don't really understand how to read this math notation. I never took any probability or statistics. How and why do you use an image histogram? I realize that an image histogram is a graphical display of an images tonal distribution (i.e. horizontal darks to lights, vertical pixel distribution), but how does one really use it and why? I mean, can't you determine everything you need just by looking at the image? How do I convert an argument list to a sequence of arguments? What is a good package for displaying algorithms? I found this page with some examples:   I'm wondering which one to use. Any suggestions? I'm using other packages too so whichever is less likely to interfere with them is better for me. Does the series $\sum\limits_{n=1}^\infty \frac{1}{n\sqrt[n]{n}}$ converge? Does the following series converge? $$\sum_{n=1}^\infty \frac{1}{n\sqrt[n]{n}}$$   As $$\frac{1}{n\sqrt[n]{n}}=\frac{1}{n^{1+\frac{1}{n}}},$$ I was thinking that you may consider this as a p-series with $p&gt;1$. But I'm not sure if this is correct, as with p-series, p is a fixed number, right ? On the other hand, $1+\frac{1}{n}&gt;1$ for all $n$. Any hints ? How can Linux/Ubuntu be installed safely on ChromeBook? Is installing Ubuntu on my Chromebook potentially dangerous to anything on my Chromebook? I got it as a gift, so I don't want to destroy anything that is important on the laptop. Also, which is better for being able to safely install Ubuntu: ChrUbuntu or Crouton? I'm using the Samsung Chromebook 3 (as described by the quick-start manual). Does that make any other differences as well? I can't see anything - Teams banner and cookie toaster obscure my whole screen There have been  for a while, but this is ridiculous. It reminds me of , but this time it's network-wide.   The banner must be scrolled past (or dismissed) on every page unless both first-party JavaScript and first-party cookies are enabled. If first-party JavaScript is enabled, and the banner is visible, the rest of the page jumps up and down every so often.  Under certain circumstances (not quite sure what they are, yet – a direct link to an answer, maybe? I'm seeing it ) the entire page jumps up and down a line every few seconds even when the banner is off-screen.   The cookie banner keeps coming back unless both third-party JavaScript  are enabled (and  is solved). The cookie box occludes the “Learn more about Teams” link in the banner (with default Firefox window sizes) and the Job / Teams link in the sidebar.  As it stands,  – a site for hobbyists and researchers, whose audience is not very likely to purchase Teams – is much, much harder to use, for no benefit that I can see. Can you roll back this change, please? Can this identity be derived from the binomial theorem?  $$n(n+1)2^{n-2} = \sum_{i=1}^{n}  i^2 \binom{n}{i}$$    I tried starting from $2^n = \displaystyle\sum_{i=0}^{n} \binom{n}{i}$ and dividing it by $4$ in order to get $2^{n-2}$. Find a bijection from $\mathbb R$ to $\mathbb R-\mathbb N$ Find a bijection from $\mathbb R \to  \mathbb R-\mathbb N$. I want to set my function up such that all natural numbers get mapped to $n+.1$ and reals of the form $n+.1$ to $2n+.1$ is this correct? Unknown Additional Driver: Processor microcode firmware for Intel CPUs for intel-microcode After upgrading to 15.04, I have one additional driver (it did not appear in 14.10). What is the purpose of this driver and should I enable it? Round function in Excel, worksheet function vs VBA I had an application for returning closest matches to certain values in a large  cluster of values( as in my earlier )   and I chose a VBA solution. While in the course of using the said application, I observed that the results for the value of 0.5 were not correct. I had been using the VBA Round function which I found to be returning 0 for 0.5 rounded to integer whereas the worksheet round function returns 1. Strangely, the VBA round function returns 2 for 1.5. I had to substitute the worksheet function in place of the VBA one.  Am I missing something? When answers are posted within a question's initial grace period, it is possible that further edits could completely change the question (see ""), and render those first few answers incorrect.   Worse yet, nobody is notified that there was a change to the question, except those that are sitting on the page and notice the edit bar pop in. And of those, only those bothered enough to open it in a new window to compare the differences, will see how much was changed.   After the grace period is up, nobody will be able to consolidate why the first few answers actually answered a different question. And the answerers won't know unless someone comments or down-votes (and in the latter case, without context, they still might have trouble understanding, unless they memorized the question's initial state).  Jon Skeet stated it pretty well in  on :     I'd like this to apply to the question, as well as answers. Sometimes I (or others) have added perfectly good answers, but then the question has been changed within the grace period, making answers look foolish without any indication of what's happened.   So this time, my proposal is quite simple:     Once an answer is posted to a question within the initial grace period, a new grace period should start, and the current state of the question should be saved as the first revision. Further edits within the next 5 minutes will be aggregated into a new, second revision.   This will only noticeably affect questions where answers are posted within the grace period and the author of the question makes edits within 5 minutes of the first answer. (Effectively, it would treat it as if a different user made an edit within the author's grace period.) All other scenarios will continue to behave as they do today.  This feature request comes close:    However, the answer suggests a simple change to the wording or a pencil icon (like we see with edited comments), without adding a revision that can be viewed and compared. I don't think this is enough - in some cases it's going to be important to know what changed, not just when. Make 15 lines / ticks with Photoshop, each of them rotated of 20° How to make a window always stay on top in .Net? Show that if $a \equiv b \pmod n$, $\gcd(a,n)=\gcd(b,n)$ Where can I find information about ubuntu compatible or certified hardware/PC models? Setting page numbering on Word I have a word document. The first four pages are title and index. After that, the “Chapter 1” starts. I want page numbers to begin from the “Chapter 1” onwards only. The first 4 pages should not have any page number.  How do I achieve this?