Recording mp3 on Windows 7 using SoX I'd like to have a SoX one-liner that would record 1 hour of audio to mp3. I'm on Windows 7. Is this possible?
How can I record sound from the windows command line? Is there an application capable of recording sound that I can run from the command line on XP?  Ideally I'd start it with one command and stop it with another. Or I could specify a duration with the starting command.
Wave equation: $y=A \sin(\omega t-kx)$ or $y=A\sin(kx-\omega t)$? What is correct wave equation: $y=A \sin(\omega t-kx)$ or $y=A\sin(kx-\omega t)$?  How are these wave equations used in the positive $x$-direction and negative $x$-direction? I want a true deep copy. In Java, this was easy, but how do you do it in C#? Proving $\frac{x}{y} +\frac{y}{z} + \frac{z}{x} \ge 3$ for positive $x,y,z$ Suppose $x,y,z$ are real positive numbers, prove that: $$\dfrac{x}{y} +\dfrac{y}{z} + \dfrac{z}{x} \ge 3$$ with equality when $x=y=z$.  Can someone help me find an easier solution? I started with assume only two are equal, without loss of generality, $x=y$. Then we get $$1 + \dfrac{x}{z} + \dfrac{z}{x}$$ $$1 + \dfrac{x^2 + z^2}{xz} = 1+ \dfrac{(x-z)^2 + 2xz}{xz} = 1 + 2 + \dfrac{(x-z)^2}{xz} \ge 3$$ To prove the general result I considered using a derivative with respect to $y$ to show that, starting with $x=y$ and increasing $y$ by a tiny amount, will show the equation's derivative as positive. I haven't gotten this to work yet. Any ideas? How to get the current directory in a C program? I'm making a C program where I need to get the directory that the program is started from.  This program is written for UNIX computers. I've been looking at opendir() and telldir(), but telldir() returns a off_t (long int), so it really doesn't help me.   How can I get the current path in a string (char array)? Proving that for a smooth function if $f(\frac 1 k)=0 :\forall k\in \mathbb N$ then $f(x)=0 :\forall x\in[-1,1]$ How can I straighten ALL the vertical UV lines at once? Is there a hot keyshort cut? Or if I have to do them one by one .. is there at shortcut for that? Thank you! Does the 90 days VWP rule expire if you travel from the US to Canada? I'm on a New Zealand passport.  From most US Embassy webpages:     The Visa Waiver Program (VWP) enables nationals of certain countries,   including Australia, New Zealand, and the U.K., to travel to the   United States for tourism or business for stays of 90 days or less   without obtaining a visa, if certain requirements are met. Under the   VWP, time spent in Canada, Mexico, and adjacent islands counts towards   the maximum of 90 days stay allowed under the program.   I'll be there on a 1-year working holiday visa starting when I arrive in Vancouver. I'm spending 3 days in Hawaii en route to Vancouver. This seems to imply that 90 days after landing in Hawaii, my time will be up and I won't be able to get back into the US, as my living in Canada will not reset the clock. What if after this time I want to say, pop across the border to Seattle? How can I restart the 90 days, without having to resort to say, flying to Japan and back just to reset it? Which package can be used to write BNF grammars? How would I change file permissions if the file name has a space in it in linux I would like to know how would I rename and change file permissions of a file that contains a space in the name on Linux.  Example  The name of my file is: my file   I have tried mv my%20file my_file  I have also tried chown -R 755 my%20file  but both of these don't work! Why do electrons not fully fill up all the orbitals sequentially? Why do electrons not fully fill up all the orbitals sequentially? By this I mean: why don't the electrons fully take up the previous orbit first and then move onto the next orbit? Take calcium for example, it's electron config is 2, 8, 8, 2. Why isn't it 2, 8, 10? Why does another orbit need to be created when there are still many spots to fill up?  (I know that this is a chemistry question in a physics forum, but I really could not find a chemistry or even a broader science type forum here ) How to run some code only when the rails console starts, kind of like an rc file? Copying prod multi-site installation to dev multi-site installation I am attempting to upgrade my Drupal 8.9.2 multi-site installation to D9. I was hoping to work this all out on a development installation, that is located in a subdirectory of my home directory on my NameCheap Shared Hosting plan. When I first installed this installation, I did so using the tarball method from years ago. I then followed the instructions given here (). I was able to get the current running prod version converted to use composer with out an issue. Before I go and start messing with the files, and attempting to upgrade to D9 through composer on a prod installation, I wanted to copy these files over to another installation where I can use it as a sandbox. To do this I:  copied the files on my server to a new directory made clone databases for the new installation truncated all the cache tables in the cloned DB changed all the database settings in the settings files to point to the cloned databases  I've done this before without any issues, and now I seem to be getting a WSOD error on all the sites running from the new installation. The error I'm getting is  PHP Fatal error:  Uncaught Error: Class 'Drupal\Core\Cache\DatabaseBackend' not found in ~/{new installation dir}/public_html/index.php:16.  If anyone has any thoughts what's going on I am all ears. Thank you in advance I'm currently unable to access anything via the Stack Exchange app under iOS; is this a known issue? Is there any program to provide a consistent interface across multiple archive types? At the moment, if I download a compressed file, it could be any of a .tar.gz archive, a tar.bz2 arhive, a .zip archive or a .gz archive. And each time I do so, I have to remember what the command line options for that program are.  Is there any CLI program where I can just go:  undocompression somefile.??  and let it figure out what format the archive is in? (overly long name used to avoid conflicting with any real program) How is it possible in Eclipse JDT to convert a multiline selection to String. Like the following  From:  xxxx yyyy zzz   To:  "xxxx " + "yyyy " + "zzz"   I tried the following template   "${line_selection}${cursor}"+   but that way I only get the whole block surrounded not each line separately. How can I achieve a multiline processing like commenting the selected block? Variation on Vandermonde's identity How can you show that $$ \binom{2n}{n}^2 = \sum_{m=0}^{n} \binom{2n}{2m} \binom{2m}m \binom{2n-2m}{n-m} $$?  I was fooling around with random walks, and apparently both expressions are supposed to be the number of unweighted random walks on a 2D square lattice of $2n$ steps that ends at the origin.  Whole thing reminds me of Vandermonde's identity but I can't it. Any hints? Thomson et al. provide a proof that $\lim_{n\rightarrow \infty} \sqrt[n]{n}=1$ in . It has to do with using an inequality that relies on the binomial theorem:  I have an alternative proof that I know (from elsewhere) as follows.  Proof. \begin{align} \lim_{n\rightarrow \infty} \frac{ \log n}{n} = 0 \end{align} Then using this, I can instead prove: \begin{align} \lim_{n\rightarrow \infty} \sqrt[n]{n} &amp;= \lim_{n\rightarrow \infty} \exp{\frac{ \log n}{n}} \newline &amp; = \exp{0} \newline &amp; = 1 \end{align}  On the one hand, it seems like a valid proof to me. On the other hand, I know I should be careful with infinite sequences. The step I'm most unsure of is: \begin{align} \lim_{n\rightarrow \infty} \sqrt[n]{n} = \lim_{n\rightarrow \infty} \exp{\frac{ \log n}{n}} \end{align} I know such an identity would hold for bounded $n$ but I'm not sure I can use this identity when $n\rightarrow \infty$. Question: If I am correct, then would there be any cases where I would be wrong? Specifically, given any sequence $x_n$, can I always assume: \begin{align} \lim_{n\rightarrow \infty} x_n = \lim_{n\rightarrow \infty} \exp(\log x_n) \end{align} Or are there sequences that invalidate that identity?  (Edited to expand the last question) given any sequence $x_n$, can I always assume: \begin{align} \lim_{n\rightarrow \infty} x_n &amp;=  \exp(\log \lim_{n\rightarrow \infty} x_n) \newline &amp;=  \exp(\lim_{n\rightarrow \infty} \log x_n) \newline &amp;=  \lim_{n\rightarrow \infty} \exp( \log x_n) \end{align} Or are there sequences that invalidate any of the above identities? (Edited to repurpose this question). Please also feel free to add different proofs of $\lim_{n\rightarrow \infty} \sqrt[n]{n}=1$. How can i get currency symbols from currency code in iphone? My Ubuntu 16.04 keeps disconnecting from the Wi-Fi (eduroam). Why? I haven't noticed any pattern and I'm sure the Wi-Fi works perfectly because I have no problems with the same computer using Windows 10. The Wi-Fi doesn't turn off though, it simply disconnects from the network and reconnects after about a couple of minutes.  I ran this and got:  lspci -knn | grep Net -A2 03:00.0 Network controller [0280]: Qualcomm Atheros AR9462 Wireless Network Adapter [168c:0034] (rev 01) Subsystem: AzureWave AR9462 Wireless Network Adapter [1a3b:2234] Kernel driver in use: ath9k Kernel modules: ath9k   Also running dmesg  Among the many messages the last one is:  [ 3818.806656] wlp3s0: Limiting TX power to 5 dBm as advertised by 00:23:eb:39:28:21   Any idea why this is happening?  Thank you. Undefined Symbol ___gxx_personality_v0 on link I've been getting this undefined symbol building with this command line:  $ gcc test.cpp Undefined symbols:   "___gxx_personality_v0", referenced from:   etc...   test.cpp is simple and should build fine.  What is the deal?