nohup tensorflow_model_server \   --rest_api_port=8501 \   --model_name=fashion_model \   --model_base_path="${MODEL_DIR}" &gt;server.log 2&gt;&amp;1   I saw this in tensorflow serving guide . I want to know the meaning of &gt; server.log 2&gt;&amp;1. I kind of know that it's about saving stdout to a file, and saving stderr to another file which I don't know what it is.
I understand that this command attempts to write to nowhere or a null device but what does 2&gt;&amp;1 mean here?  wget -q -O - http://yourwebsite.com/wp-cron.php?doing_wp_cron &gt; /dev/null 2&gt;&amp;1
Having trouble creating an array of objects How to get the current time in Python What is the module/method used to get the current time? Javascript infamous Loop issue? Dual boot Ubuntu with Windows on Acer Aspire I've installed Ubuntu 16.04 LTS along side with Windows 10 (I shrinked my Disk using Windows Disk Management) on my Acer laptop (ES1-531-C13G), but when I restart/reboot my system no menu (Grub screen) appears from where I can select the operating system that I want to boot with, but instead, system takes me into Windows 10 everytime. I've tried several things from internet including :    Ran bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi from windows command prompt.  Reset  Bootorder i.e. first Ubuntu then Windows from Ubuntu terminal (after successful Ubuntu installation) etc, but nothing works for me so far. Please guide me ! I never really bothered to keep my Hotmail contact information up to date, so now that I connected it to Windows 8, suddenly I see all this outdated contact information or people I've long stopped talking to.    I don't see any buttons or options where I can click to delete someone.  So how do I clean up my Windows 8 People app and remove these contacts? Can we theoretically balance a perfectly symmetrical pencil on its one-atom tip? I was asked by an undergrad student about this question. I think if we were to take away air molecules around the pencil and cool it to absolute zero, that pencil would theoretically balance.  Am I correct?  . Electrical potential energy stored in vacumm for a single point charge? I have come to know the electrostatic potential energy in vacuum is given by $${\frac{1}{2}} \epsilon_0\int d^3x {E^2} $$ and this energy  is due to the mutual electrostatic coulomb potential energy. So only a single point charge in space also contributes to some electrostatic potential energy according to $${\frac{1}{2}} \epsilon_0 \int d^3x {E^2} $$  as due to a single point charge also we have an electric field at every point in space. Now I am not getting it physically, why should there be any Coulomb energy in this case as there is no other charge to provide the electrostatic coulomb potential energy? I have read in a book that the limit of the ratio of consequent Fibonacci numbers is the golden ratio. However, it was just mentioned thus not justified. So, my question is how would you derive the following limit: $$\lim_{x\to\infty}{\frac{F_n}{F_{n+1}}}=?$$ Where $F_n$ is the nth Fibonacci number? Highlight \verb in inline text How can I send mail from an iPhone application The set of integers $n$ expressible as $n=x^2+xy+y^2$ How do I check if someone accessed my computer? I need to check the list of files accessed in my computer (ex: yesterday on particular time). Is it possible?   Or   I need to check whether anybody accessed my computer (when I left it unlocked) or not for a particular time. Where $F$,$K$ are two fields. What does the element in the composite field $FK$ look like? All the elements are generated by the elements of $F$ and $K$? (combination of the elements of $F$ and $K$) I think $FK$ is pretty close to the free product of $F$ and $K$; is $FK \subsetneq F*K$? Thank you! macOS Catalina File Structure: Cannot remove &gt; sudo rmdir /sw rmdir: /sw: Read-only file system  &gt; mount | grep read /dev/disk1s5 on / (apfs, local, read-only, journaled)  &gt; sudo mount -o rw / &gt; mount /dev/disk1s5 on / (apfs, local, journaled) &gt; sudo rmdir /sw rmdir: /sw: Operation not permitted     root /&gt;$ mkdir a root /&gt;$ rmdir a root /&gt;$ rmdir sw &lt;b&gt;rmdir: sw: Operation not permitted&lt;/b&gt; root /&gt;$ rmdir opt &lt;b&gt;rmdir: opt: Operation not permitted&lt;/b&gt; root /&gt;$ rmdir mnt &lt;b&gt;rmdir: mnt: Operation not permitted&lt;/b&gt; root /&gt;$ rmdir home &lt;b&gt;rmdir: home: Operation not permitted&lt;/b&gt;   What exactly is preventing me from removing these directories even with SIP disabled? $\mathbb{R}$ \ $\mathbb{Q}$ and $\mathbb{R}^2\setminus\mathbb{Q}^2$ disconnected? If I want to prove that $\mathbb{R} \setminus \mathbb{Q}$ is disconnected, does it suffice to say that there are two open disjoint sets that cover $\mathbb{R}\setminus\mathbb{Q}$, namely:  $$(- \infty, 0), (0, \infty)\text{ ?}$$  Along the same lines, I want to prove or disprove that $S = \mathbb{R}^2 \setminus \mathbb{Q}^2$ (points $(x, y) \in S$ that have at least one irrationais connected. I feel that it is also disconnected; does it suffice to say that there are two open disjoint sets that cover $S = \mathbb{R}^2 \setminus \mathbb{Q}^2$, namely $((- \infty, - \infty), (0, 0))$ and $((0, 0), (\infty, \infty))$? (Very iffy on my assertion and my notation, sorry.)  Thanks! If $f'(c)$ exists then $\lim_{x\to c} f(x)=f(c)$ If $f'(c)$ exists then $\lim_{x\to c} f(x)=f(c)$   My attempt is below. Did I do wrong? Since I don't really understand it. I thought $f'(x) = f'(c)$ so $f'(x)-f'(c)=0$. Am I on the right track? Many thanks!  \begin{align} f(x)-f(c)&amp;=\frac{f(x)-f(c)}{x-c}\cdot(x-c) \\ \lim_{x\to c}[f(x)-f(c)]&amp;=\lim_{x\to c}\left[\frac{f(x)-f(c)}{x-c}\cdot(x-c)\right] \\ \lim_{x\to c}[f(x)-f(c)]&amp;=0 \\ \lim_{x\to c} f(x)&amp;=f(c) \end{align} How does Fermat's principle make light choose a straight path over a short path? This is a thought experiment where I have made a &quot;C&quot; shaped hole inside diamond. The refractive index $(\mu)$ of diamond is 2.45. Say we shine a laser from top of the &quot;C&quot; as shown. My calculations show that light reaching A can reach B in the least possible time if gone through the &quot;C&quot;. but I'm pretty sure the perpendicular laser beam travels undeflected and straight down. Though I don't have experimental evidence, I see something wrong either with my intuition or with the theory. It would be great if someone could clarify. *       'a' in the diagram is the thickness of the cutout and all comparable distances can be taken 'a'. What is the VTable Layout and VTable Pointer Location in C++ Objects in GCC 3.x and 4.x? adding an item to filtered table My project has a table with '+add' button and filtering. The add button opens a dialog to add item, and then to 'save' which closes it too Today I noticed the following flow:  Filter table on subject with value 'dummySubject'  Add new item with subject 'somethingelse'  save and close the new item ==&gt; the new item is shown in the table   So the outcome is that an item that does not qualify the filtering appears in the table. When I asked around I got the following answer  We don't want the new item to 'disappear' on creation just because it does not qualify the filtering. So we display it If you filter again, it will disappear as it should  I can almost understand that logic, but still it sounds wrong. I would rather have like a toaster saying 'new item create' with a 'goto' link. My question is  is the current user experience considered a reasonable one? what is the best practice way to handle such scenario?      &ndash; Wireframes created with Since I've a database systems examination in less than 3 hours (from now), I have been browsing Stack Exchange network for questions with normalisation and related tags. Most of the questions are now closed as  or others from the list.  Since, these questions are closed, no users are allowed to post answers to them (unless they are reopened). Why am I, then, allowed the option to protect such questions? Doesn't that beat the entire purpose behind "protecting" a question?