I have a process I want to start from Java. The problem is that due to a mismatch between the remote desktop client and the process I want to start I need to modify the environment variables. I will not use this in production, but only for running tests. I will also just do this until this bug is fixed in the tool I use.  I do not have root access and I am using Linux RHEL7. Anyone having an idea how I can set this environment variable from Java? I should also add that I run this from an IDE.  The following answer was not very helpful due to the lack of actual examples:   and the following example was not able to set the variables in the scope I needed to set them:   I tried this,  Process p = Runtime.getRuntime().exec("setenv " + name + " " + value);   But get the following error message,  java.io.IOException: Cannot run program "setenv": error=2, No such file or directory   EDIT: Someone suggested this post,    Unfortunately I do not find any solutions in there. The process I want to start already have a Java API, which does not work in my environment. What I want is an equivalent to the linux command,  setenv NAME VALUE   for the process which java runs in.
How do I set environment variables from Java?  I see that I can do this for subprocesses using . I have several subprocesses to start, though, so I'd rather modify the current process's environment and let the subprocesses inherit it.  There's a System.getenv(String) for getting a single environment variable. I can also get a Map of the complete set of environment variables with System.getenv(). But, calling put() on that Map throws an UnsupportedOperationException -- apparently they mean for the environment to be read only. And, there's no System.setenv().  So, is there any way to set environment variables in the currently running process?  If so, how?  If not, what's the rationale?  (Is it because this is Java and therefore I shouldn't be doing evil nonportable obsolete things like touching my environment?)  And if not, any good suggestions for managing the environment variable changes that I'm going to need to be feeding to several subprocesses?
Cannot update/get any packages. gedit not installed my problem is that my sources.list is out of date for some reason. I already found the fix in another port, but it doesn't work. It says to use gedit to edit sources.list and replace everything with the proper sources. Well, for some reason I don't have it installed (Ubuntu Server 14.04) and I can't install it or else I get the main problem again.  Failed to fetch http:// some ubuntu site Could not resolve hostname "us.archive.ubuntu.com"  Is there any other way to edit sources.list? Or do I need to do a re-install of the OS? Why is the camera tilting around the z axis when I only specified x and y? My goal is to program a camera to point towards the mouse cursor. I attached the following script to the Main Camera.   using UnityEngine; using System.Collections;  public class CameraController : MonoBehaviour {      public float sensitivity;      // Update is called once per frame     void Update () {         transform.Rotate (Input.GetAxis ("Mouse Y") * -1 * sensitivity, Input.GetAxis ("Mouse X") * sensitivity, 0);     } }   I "told" the camera to rotate around the x and y axes. Whenever it does this, the camera tilts sideways. When I checked the rotation of Main Camera, I saw that the z rotation had changed. Why is it rotating around the z axis when I left it at 0? Proof of greatest integer theorem: floor function is well-defined I have to prove that  $$\forall x \in \mathbb{R},\exists !\,n \in \mathbb{Z} \text{ s.t. }n \leq x &lt; n+1\;.$$  where $\exists !\,n $ means there exists a unique (exactly one) $n$. I'm done with proving that there are at least one integers for the solution. I couldn't prove the &quot;uniqueness&quot; of the solution, and so I looked up the internet, and here's what I found:  Let $\hspace{2mm}n,m \in \mathbb{Z} \text{ s.t. }n \leq x &lt; n+1$ and $m \leq x &lt; m+1$. Since $n \leq x \text{ and } -(m+1) &lt; -x$, by adding both, $n + (-m-1) &lt; (x-x) = 0$. And (some steps here) likewise, $(x-x) &lt; n+m+1$.  Now, can I add up inequalities like that, even when the book is about real analysis (and in which assumptions are supposed to be really minimal)? Or should I also prove those addition of inequalities? Thank you :D The question is:     When $f(x+1)-f(x)=f'(x)$, what are the solutions for $f(x)$?   The most obvious solution is a linear function of the form $f(x)=ax+b$. Is this the only solution?  Edit  I should add that $f:\mathbb R\to\mathbb R$ to the question. In ideal gas model,  is the measure of average kinetic energy of the gas molecules. If by some means the gas particles are accelerated to a very high speed in one direction, KE certainly increased, can we say the gas becomes hotter? Do we need to distinguish the random vibration KE and KE in one direction?  Furthermore, if we accelerate a block of metal with ultrasonic vibrator so that the metal is vibrating in very high speed with cyclic motion, can we say the metal is hot when it is moving but suddenly become much cooler when the vibration stop? I have a question, to aid my understanding, about the proof that differentiability implies continutity.$\mathstrut$    Differentiability Definition  When we say a function is differentiable at $x_0$, we mean that the limit:  $$‎f^{\prime} ‎(x) = \lim_{x\to x_0} \frac{f(x) - f(x_0)}{x-x_0}$$ exists.  Continuity Definition  When we say a function is continuous at $x_0$, we mean that: $$\lim_{x\to x_0} f(x) - f(x_0) = 0$$  Theorem: Differentiability implies Continuity: If $f$ is a differentiable function at $x_0$, then it is continuous at $x_0$.  Proof:  Let us suppose that $f$ is differentiable at $x_0$. Then $$ \lim_{x\to x_0} \frac{f(x) - f(x_0)}{x-x_0} =  ‎f^{\prime} ‎(x) $$  and hence  $$ \lim_{x\to x_0} f(x) - f(x_0) = \lim_{x\to x_0} \left[ \frac{f(x) - f(x_0)}{x-x_0} \right] \cdot \lim_{x\to x_0} (x-x_0) = 0$$  We have therefore shown that, using the definition of continuous, if the function is differentiable at $x_0$, it must also be continuous.  My Question  The proof seems to execute the following steps:   Assume the function is continuous at $x_0$ Show that, with little algebra, we can change this into an equivalent question about differentiability at $x_0$. With this little bit of algebra, we can show that if a function is differentiable at $x_0$ it is also continuous.   What I am slightly unsure about is the apparent circularity. In my mind it seems to say, if a function is continuous, we can show that if it is also differentiable, then it is continuous. Rather than what I was expecting, namely, if a function is differentiable, we can show it must be continuous.  Hopefully my confusion is clear. Any help will be greatly appreciated. Why are there 2 packages for some applications (e.g. Chromium) in Ubuntu Software? When I search for Chromium in Ubuntu Software on Ubuntu 16.04, There are 2 options.    Which one should I select?    The same can be observed with , ,  etc. Because of a former error in our ASP.Net application, created by my predecessor and undiscovered for a long time, thousands of wrong URLs where created dynamically. The normal user did not notice it, but Google followed these links and crawled itself through these incorrect URLs, creating more and more wrong links.  To make it clearer, consider the url     example.com/folder   should create the link     example.com/folder/subfolder   but was creating     example.com/subfolder   instead. Because of bad url rewriting, this was accepted and by default showed the index page for any unknown url, creating more and more links like this.     example.com/subfolder/subfolder/....   The problem is resolved by now, but now I have thousands of 404 errors listed in the Google Webmaster Tools, which got discovered 1 or 2 years ago, and more keep coming up.  Unfortunately the links do not follow a common pattern that I could deny for crawling in the robots.txt.  Is there anything I can do to stop google from trying out those very old links and remove the already listed 404s from Webmaster Tools? Copy every 512 bytes and skip next 8 bytes from Input file to a Output file I have an input file which is always a multiple of 520 bytes . i,e Input file 1- 1040 bytes Input file 2- 5200 bytes   I need to copy every 512 bytes from input file and skip the next 8 bytes from input files to output file i.e Output file data = Copy first 512 bytes of input file - Skip 8 bytes - Copy second 512 bytes of input file- Skip 8 bytes --.. Therefore, my output file should always be multiple of 512 bytes Input file 1- 1040 bytes        Output file 1 - 1024 bytes Input file 2- 5200 bytes        Output file 2 - 5120 bytes  I need to do this in shell script, any help here please. El Captain update download doesn't continue after restarting the Mac I started to download the El Capitan upgrade, but then I shut down my computer. The day after I wanted to continue the download but in App Store it shows "Waiting..." and doesn't do anything. Also when I go to the updates section, it shows the button "Download" but it's inactive. Maybe someone can help me? I tried to find the download file in some directory to delete it and start over but I couldn't find it. Who should own files shared by a group and where should they go update-java-alternatives vs update-alternatives --config java On Ubuntu 12.04 LTS I have installed Sun's JDK7, Eclipse, and the Arduino IDE. I want the Arduino to use OpenJDK 6 and want Eclipse to use Sun's JDK 7.   From my understanding I need to manually choose which Java to use before running each application. This led me to the update-java-alternatives -l command. When I run this I only see the following:   java-1.6.0-openjdk-amd64 1061 /usr/lib/jvm/java-1.6.0-openjdk-amd64   but when I run update-alternatives --config java I see the following:   *0  /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java   auto mode 1  /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java   manual mode 2  /usr/lib/jvm/jdk1.7.0/bin/java                   manual mode 3  /usr/lib/jvm/jre1.7.0/bin/java                   manual mode   I don't understand why the update-java-alternatives doesn't display the same 3 options. I also don't understand how to switch between OpenJDK6 and JDK7. How I can go about using the OpenJDK6 for Arduino development and Sun JDK7 for Eclipse/Android development? Pointwise convergent and total variation I'm preparing for a test for real analysis and I came across this problem in Royden's book:  Let $\{f_n\}$ be a sequence of real valued functions on $[a,b]$ that converges pointwisely on $[a,b]$ to the real valued function $f$. Show that $TV(f) \leq \liminf  ~TV(f_n)?$  This looks quite similar in form to Fatou's Lemma to me, but can't find any way to establish TV with integration, can anybody please help?  (TV is short for total variation) What is the difference between \emph{...} and {\em ...}?  When to use each of them? series of young adult science fiction books from early 1980s about last of a race of martial experts that sees the destruction of his home planet I remember that the main character is trying to find the group that destroyed his home planet while he was on a mission. His planet was very difficult to live on and the people became expert in martial arts and were the best soldiers in the galaxy. They were mercenaries and often helped against tyrants. There was a very memorable section in at least one book about an initiation task that the main character had to do in that he had to survive in their wilderness for days. He was at some point surrounded in a old building by thousands of poisonous worm/snake creatures that he managed to survive until rescued by the leaders. 2 prong to 3 prong outlet help UV mapping a straight image around a ring shaped flat mesh Is it possible to mapping a image around a ring shaped mesh? I would imagine there should be a way to curve/distort the image around the mesh. If not, how can I straighten out the mesh easily instead to fit the image? What is the purpose of LongLength for .Net Arrays? What will happen when Winter Bash is over? Tomorrow (January 2nd 2019) is the day that Winter Bash will be gone.  So I am thinking: Will there be some sort of a final ranking page anywhere?  It would be nice so I don't need to keep going to  every day to see my rank.  If there isn't going to be anything like that, what should I do to see my final rank on Winter Bash? Calculation of the avalanche effect coefficient Given a  matrix/dependence matrix for a hash function,how do I calculate the avalanche coefficient for it. I want to calculate a single parameter(value) which represents the amount of avalanche effect for the given hash function.  I have thought of computing mean all over the matrix but am not sure that's the correct thing to do.  The  talks about the avalanche coefficient but they haven't mentioned the way they calculate it.