How to check for presence of named pipe on the file system
Write to FIFO only if it exists
Minor grid in pgfplot not showing when specifying ticks manualy Firstly I would like a minor tick between every major tick in my pgfplots graph (and minor grids). I wrote minor tick num=1 but it doesn't work. I am not using a logarithmic axis so it is unrelated to other questions.  Secondly, why is the tick label "1" missing for each axis? How do I get that to display?     \documentclass{standalone} \usepackage{pgfplots} \begin{document} \begin{tikzpicture}  \begin{axis}[% footnotesize, width=4in, height=4in, axis equal, scale only axis, separate axis lines, grid=both, every outer x axis line/.append style={black}, every x tick label/.append style={font=\color{black}}, xmin=0, xmax=1, xlabel={X}, every outer y axis line/.append style={black}, every y tick label/.append style={font=\color{black}}, ymin=0, ymax=1, ylabel={Y}, minor tick num=1, xtick={0,0.1,...,1}, ytick={0,0.1,...,1}, axis background/.style={fill=white}, legend style={at={(0.97,0.03)},anchor=south east,legend cell align=left,align=left,fill=white} ]  \end{axis}  \end{tikzpicture}% \end{document} Let $\alpha$ be an irrational real number and let $a_j$ be a sequence of rational numbers converging to $\alpha$. Suppose that each $a_j$ is a fraction expressed in lowest terms: $a_j = \alpha_j / \beta_j$. Prove that the $\beta_j$ tend to $\infty$  Attempt: AFSOC that $\beta_j$ does not tend to infinity, then it is bounded by some $M$. We can also find an interval $\alpha \in (k, k+1)$. Let $\epsilon &gt; 0$, $\exists N_0$ such that for all $N &gt; N_0$ we have $|a_N - \alpha|  &lt; \epsilon$. So $|\frac{p_N}{q_N} - \alpha| &lt; \epsilon$. We try to use the fact that $q$ is bounded but fail to derive a contradiction. I do not know how to use the fact that $\alpha$ is between two integers, although it might not be relevant at all.  Ideas? Split comma-separated values PostgreSQL crash when connection failed Error log is:  016-02-21 21:22:34 GET DETAIL:  Connection matched pg_hba.conf line 83: "host    all             all             ::1/128                 md5" .... .... 2016-02-21 21:22:37 GET DETAIL:  Connection matched pg_hba.conf line 83: "host    all             all             ::1/128                 md5" 2016-02-21 21:22:37 GET FATAL:  password authentication failed for user "postgres" 2016-02-21 21:22:37 GET DETAIL:  Connection matched pg_hba.conf line 83: "host    all             all             ::1/128                 md5" 2016-02-21 21:22:37 GET LOG:  CreateProcess call failed: A blocking operation was interrupted by a call to WSACancelBlockingCall.       (error code 299) 2016-02-21 21:22:37 GET LOG:  could not fork new process for connection: No error 2016-02-21 21:22:37 GET LOG:  incomplete startup packet 2016-02-21 21:22:38 GET FATAL:  password authentication failed for user "postgres" 2016-02-21 21:22:38 GET DETAIL:  Connection matched pg_hba.conf line 83: "host    all             all             ::1/128                 md5" 2016-02-21 21:22:42 GET FATAL:  password authentication failed for user "postgres" 2016-02-21 21:22:42 GET DETAIL:  Connection matched pg_hba.conf line 83: "host    all             all             ::1/128                 md5" 2016-02-21 21:24:26 GET LOG:  could not receive data from client: An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full. 2016-02-21 21:24:26 GET LOG:  incomplete startup packet 2016-02-21 21:24:29 GET FATAL:  password authentication failed for user "postgres" 2016-02-21 21:24:45 GET PANIC:  could not write to log file 000000010000000100000041 at offset 4259840, length 8192: Invalid argument 2016-02-21 21:24:45 GET STATEMENT:  COMMIT 2016-02-21 21:24:53 GET LOG:  server process (PID 470944) was terminated by exception 0xC0000409 2016-02-21 21:24:53 GET DETAIL:  Failed process was running: COMMIT 2016-02-21 21:24:53 GET HINT:  See C include file "ntstatus.h" for a description of the hexadecimal value. 2016-02-21 21:24:53 GET LOG:  terminating any other active server processes   Can anyone help to solve the problem? I spent many hours but didn't find a solution.   Postgres version 9.4 Operating System: Windows  postgresql.conf is:  listen_addresses = '*' port = 5432  max_connections = 100 shared_buffers = 128MB   dynamic_shared_memory_type = windows   pg_hba.conf is:  # IPv4 local connections: host    all             all             127.0.0.1/32            md5 host    all             all             0.0.0.0/0               md5 $\DeclareMathOperator{\Char}{char}$$\DeclareMathOperator{\Aut}{Aut}$ Let $G$ be a finite group, $H$ a subgroup, such that $H \Char G$. If $\phi \in \Aut(H)$ is there an automorphism $\widehat{\phi} \in \Aut(G)$ such that $\widehat{\phi}|_H$ = $\phi$?  In words, if $\phi$ is an automorphism of $H$, is there necessarily an automorphism $\widehat{\phi}$ of $G$ where $\widehat{\phi}$ maps the elements in $H$ to $H$ in exactly the same way?  I am thinking this is false (consider the non-finite example of $\bar{Q}$ and $\mathbb{C}$), but would like a counter example (for the finite case). The keyboard I am trying to create has a lot of Unicode and looks like this:   Being unsuccessful with the following tutorial:    (There are a few errors in the tutorial, and it uses imprecise language such as "Cutting" things instead of "Deleting" them, and it is formatted strangely)   I was wondering if anybody would be so kind to provide a better tutorial with step by step instructions? How can I get a complete list of fields for a standard object? I am new to Apex, but it is apparent to me that most (if not all) standard objects probably have an ID field. However, this field does not appear in the reference for the standard objects in the Soap API Developer's Guide. Instead, it reads:     To verify the complete list of fields for an object, you can use a   describe call from the API, or inspect with an appropriate tool, for   example, inspecting the WSDL or using a schema viewer.   If I want to find out for sure whether an object has an ID field, or what the field is named (is it ID, Identifier, id, etc), it sounds like I need to use a "describe call" or "an appropriate tool" or inspect the "WSDL" using a "schema viewer".  Now, I am an experienced software developer, but those solutions are so ambiguous I have no idea where to look next to figure out how to get an object's ID. Can anybody either refer me to more specific documentation, or explain how to find the complete field documentation via a "describe call", "appropriate tool", or "schema viewer"? I did some calculation and found out, that my Living End deck (modern) might be better of with 66 cards maindeck. SB still contains of 15 cards. Depending on the match up, I'd like to cut my deck for game two down to the normal 60. The SB than would contain 15+6 = 21 cards. Is this legal? I'm trying to install CentOS 7 on a HP DL120 gen 9 server with a b140i controller. I have 4 1TB HDD setup in a raid 1+0 and the CentOS installer doesn't seem to recognize the logical drive created from the storage utility.  From my understanding i need some drivers for CentOS 7 to recognize the B140i controller. Also, the driver seems to be closed source by HP.  What is my approach here? Is there any other free linux OS that i can use on this server and that would recognize the raid controller?  Thank you. Set the location in iPhone Simulator "have" vs."have got" in American and British English I have looked through several questions and answers on EL&amp;U, and often there is an indication that American English prefers "have" while British English prefers "have got". In addition, there are several references to "have got" being more informal than "have" (e.g.: , ). But where is it considered more informal? In American English alone or both American and British English?   This point may seem obvious to those who made the above mentioned references, but the fact is that even the most fluent users of English in my country will say without a doubt that 'have got' is the preferred usage in the UK and, therefore, it must also be more formal. Why? Because in an academic environment, the more informal structures are generally frowned upon, outside some specific spoken exercises. And if the teachers insist on using "have got", it follows it isn't informal.  So, is the teaching of (British) English in our schools transmitting the wrong idea?  EDIT: I'm adding some information in answer to the comments.  I'm mainly concerned with the idea of possession:      I have got a cat vs. I have a cat and She has got a dog vs. She has a dog   As mentioned in the comments, every (Portuguese) student will be told that "have" and "have got", when it comes to the idea of possession, are absolute synonyms, the only two differences being:    "have got" is preferred by British English, "have" is preferred by American English   the negative and interrogative structures differ    I have never heard of any distinction in formality. In fact, I was rather surprised when I went through the EL&amp;U archives and read about it.  So, would "I have got a cat" be as formal/informal as "I have a cat"?   And how do British and American English look at its formality/informality? Is it the same? Supremum and Infimum Let $A$ be a nonempty set of real numbers which is bounded below. Let $-A$ be the set of all numbers $-x$, where $x \in A$. Prove that $\inf A = -\sup(-A)$.   We know that $-A$ is bounded above. Hence $\sup(-A)$ exists. So to proceed, one would show that $\inf A \leq -\sup(-A)$ and $\inf A \geq -\sup(-A)$? Or $-\inf A &gt; \sup(-A)$ and $-\inf A &lt; \sup(-A)$.  I get the sense that one can use the following fact as well: (i) Let $\alpha = \sup S$. If $\beta &lt; \alpha$ then $\beta$ is not an upper bound for $S$. Scale Image Using PHP and Maintaining Aspect Ratio Switching window manager/desktop environments? In general what is the approach to switch the desktop environment or window manager on Ubuntu? The main difference between stock Ubuntu, Kubuntu and Lubuntu is supposedly the use of Unity vs. KDE vs. LXDE.  However, in order to try various desktop environments and window managers I don't want to have to reinstall the respective flavor from scratch just to get a particular desktop environments or window manager. There probably is an easier method than that.  The question: How can I easily test different desktop environments and respective compatible window managers (say KDE, LXDE, Unity, GNOME, XFCE and StumpWM)? I want to store courseworks marks of n courseworks into n variables, such as cw1 and cw2 etc. Using variable variables how can I come with cw1, cw2 etc.   How can I dynamically create variables? If $(a,b)=1$ then prove $(a+b, ab)=1$. Let $a$ and $b$ be two integers such that $\left(a,b\right) = 1$. Prove that $\left(a+b, ab\right) = 1$.   $(a,b)=1$ means $a$ and $b$ have no prime factors in common  $ab$ is simply the product of factors of $a$ and factors of $b$.  Let's say $k\mid a+b$ where $k$ is some factor of $a$.  Then $ka=a+b$ and $ka-a=b$ and $a(k-l)=b$.  So $a(k-l)=b, \  a\mid a(k-1)$ [$a$ divides the left hand side] therefore $a\mid b$ [the right hand side].  But $(a,b)=1$ so $a$ cannot divide $b$.  We have a similar argument for $b$.  So $a+b$ is not divisible by any factors of $ab$.  Therefore, $(a+b, ab)=1$.  Would this be correct? Am I missing anything? How to find the limit of a sequence? Question:  If $0 &lt; x &lt; \frac{\pi}{2}$ and $f_k(x) = \tan(x)+\frac{1}{2}\tan(x/2)+ ...+\frac{1}{2^k}\tan(x/2^k)$.  In Sigma Notation: $$f_k(x) = \sum_{n=0}^k \frac{1}{2^n}\tan\frac{x}{2^n}$$  Find $$\lim_{k\to \infty}f_k(x)$$  I'm not quite sure how to take the limit of a sequence, I've never seen this before, If someone could help me solve this it would be greatly appreciated. Is it correct to use "their" instead of "his or her"? What are the different endings in Dishonored? Could not download all repository indexes