Save output of multiple commands to the same file
Redirect output from all commands to file, not just last
Can you travel to the US prior 1 months of tourist visa expiry? I've heard that i can travel to the US any time before my tourist visa expiry.  Is that true?  (please advise) "Stack Overflow requires external JavaScript from another domain" message Let $(a_n)_{n}\in\ell^2:=\ell^2(\mathbb{R})$ be a fixed sequence. Consider the subspace $$C=\{(x_n)_{n}\in\ell^2 : |x_n|\le a_n\text{ for all }n\in\mathbb{N}\}.$$  According to the book [Dunford and Schwartz, Linear operators part I, page 453] $C$ is compact in the $\ell^2$-norm, but there is no proof. How can I show that $C$ is indeed compact in $\ell^2$ ? motion tracking : how to extract 3d position from selected 2d tracker I already solve my camera and created 3d scene successfully. Now i want to do 2d track the original clip and by using solving data, i want to extract that specific point into 3d coordinate (as empty object or plain axes). How can i do this ?  Thanks I've been reading up on STL containers in my book on C++, specifically the section on the STL and its containers. Now I do understand each and every one of them have their own specific properties, and I'm close to memorizing all of them... But what I do not yet grasp is in which scenario each of them is used.  What is the explanation? Example code is much prefered. Do I need to upgrade RAM from 4GB to 8GB for Android development? I'm an android developer and have laptop with 4GB RAM. When I compile my project the RAM is used at 100%.    If I add more RAM will it solve the problem? This is on Stack Overflow. On Meta I'm able to see what the tags are on the right side of the screen. In fact, I think yesterday or some point earlier today I saw tags on the right side of the screen (I can't screenshot or remember correctly).  It's right above the asked and active heading.  I know this is minor but what happened to it? It might be useful for browsing instead of having to look at the bottom of the question post.    Found an image on Google and it shows the tags on the right side of the screen: Suppose we have a magnetic field directed into the computer screen. Assume that there is no gravitational field. Now suppose we have a stationary positively charged particle in the magnetic field. The magnetic force is given by $$\mathbf{F}=q\mathbf{v}\times\mathbf{B}$$  Since $\mathbf{v}=0, \mathbf{F}=0$.  Now pick a reference frame moving to the left with constant velocity. In this frame, the particle is moving to the right with constant velocity. So, the magnetic force is directed upwards.  From what I've learnt in physics, forces are independent of choice of reference frames as long as the frames are inertial. But in the 2 inertial reference frames I have chosen, I get 2 different magnetic forces. How do we reconcile this? Why does parameter expansion with spaces without quotes work inside double brackets "[[" but not inside single brackets "["? To avoid printing single letters at varying sizes and measuring how far away I can see it from a distance is there a formula for determining what size font for a particular read distance? Is it better to take the midpoint between the ascender line and x-height or to go purely off of the x-height (since going purely off the ascender line could leave lowercase letters difficult to read)? How does vertical height play into this? Would I need to then figure the hypotenuse distance instead of a straight distance?  For example if I'm shooting for a 20' read distance but the sign is to be placed about 30' up should I use a distance of  35' instead of 20'?  I'm shooting for a 20' read distance for the headline and then possibly a 10' read distance for additional content depending on how it all fits on the active area. Can truesight see through a druid's Wild Shape? The rules for truesight state:     A creature with truesight can (..) perceive the original form of a shapechanger or a creature that is transformed by magic   A druid player argued that since the druid is still a "humanoid" (not a "shapechanger"), and since , a creature with truesight should not see through it.  As the DM, I ruled against it because I believed the intent of truesight is to see through all kinds of shapechanging effects but I was still left wondering if I missed anything. I couldn't find anything about this in the errata either.  So, going by strict RAW, should a creature with truesight be able to see the druid's true form while a druid is using wild shape? What are the applications of the ## preprocessor operator and gotchas to consider? As mentioned in many of my previous questions, I'm working through K&amp;R, and am currently into the preprocessor. One of the more interesting things &mdash; something I never knew before from any of my prior attempts to learn C &mdash; is the ## preprocessor operator. According to K&amp;R:     The preprocessor operator ##   provides a way to concatenate actual   arguments during macro expansion. If a   parameter in the replacement text is   adjacent to a ##, the parameter is   replaced by the actual argument, the   ## and surrounding white space are   removed, and the result is re-scanned.   For example, the macro paste   concatenates its two arguments:      #define  paste(front, back)  front ## back      so paste(name, 1) creates the token   name1.   How and why would someone use this in the real world? What are practical examples of its use, and are there gotchas to consider? $X$ is homeomorphic to $X\times X$ (TIFR GS $2014$) Question is :  Suppose $X$ is a topological space of infinite cardinality which is homeomorphic to $X\times X$. Then which of the following is true:   $X$ is not connected. $X$ is not compact $X$ is not homeomorphic to a subset of $\mathbb{R}$ None of the above.   I guess first two options are false.  We do have possibility that product of two connected spaces is connected.  So, $X\times X$ is connected if $X$ is connected. So I guess there is no problem.  We do have possibility that product of two compact spaces is compact.  So, $X\times X$ is compact if $X$ is compact. So I guess there is no problem.  I understand that this is not the proof to exclude first two options but I guess the chance is more for them to be false.  So, only thing I have problem with is third option.  I could do nothing for that third option..  I would be thankful if some one can help me out to clear this.  Thank you :) What should I do when my neural network doesn't generalize well? I'm training a neural network and the training loss decreases, but the validation loss doesn't, or it decreases much less than what I would expect, based on references or experiments with very similar architectures and data. How can I fix this?    As for question        to which this question is inspired, the question is intentionally left general so that other questions about how to reduce the generalization error of a neural network down to a level which has been proved to be attainable, can be closed as duplicates of this one.  See also dedicated thread on Meta: No file output after rendering? I usually am able to render successfully to the c:\tmp folder, but when I came into work today, I rendered out the image on my work laptop, and everything seems to work, but I'm not getting an output to the tmp directory.  Does anyone know how to make this work? Deep learning model (LSTM) with temporal and non temporal attributes What conditions are necessary for a Wither Skeleton to spawn naturally, and can I manipulate those conditions to increase the chance of them spawning?  I want to make a Wither Skeleton spawning pad in the Nether but I'm having trouble finding Wither Skeletons. I've only heard that they spawn in Nether Fortresses. I saw a commercial on televison for preparing spaghetti without boiling the noodles, just place them in water for about on hour.  Can this be done? crisscross, dillydally, riffraff, etc Secure an Ubuntu OpenSSH server from Brute force attacks but without a firewall or SSH key pair? I use Ubuntu 16.04 and seek to harden my SSH authentication in a special manner.  The current situation:  I have a machine with a minimal Ubuntu server I use mainly to transfer files to via its local OpenSSH server. Now, I don't have a firewall on that machine from a few reasons and I also avoid using a key pair hence I use only a password. One of the only ways I have left to defend from brute force attacks, and the one I most desire at the moment, is using a mechanism that blocks a user for X amount of hours, after Y amount of connection tries.  The desired situation:  I wish to have a standalone mechanism (that is, not as part of a firewall) that blocks a user for X amount of hours, after Y amount of connection tries as a way to defend from brute force attacks.  My Question:  Do you know a utility (and specific configuration) that will let me achieve the desired situation?