grep or find a pattern in all directories
Recursive grep vs find / -type f -exec grep {} \; Which is more efficient/faster?
The game  has a very unique intro that I would like to show my friend again for the first time. I'm not sure how to reset all my progress on this game to achieve this though. Any thoughts? $\lim_{n \rightarrow\infty} ~ x_{n+1} - x_n= c , c > 0$ . Then, is $\{x_n/n\}$ convergent? Story about last 2 men on Earth. One very evil, and the other very ethical How to plot a graph from its adjacency matrix and coordinates of vertices? A similar question is . If we give all the data of the vertices's coordinates and the graph's adjacency matrix, how to plot it with tikz, pstrick or other tool in tex?   here are the data of adjacency matrix and coordinates  Coordinates:{{0.809,0.588},{0.309,0.951},{-0.309,0.951},{-0.809,0.588},{-1.,0.},{-0.809,-0.588},{-0.309,-0.951},{0.309,-0.951},{0.809,-0.588},{1.,0.}}  Adjacency matrix: {{0,1,0,0,1,0,1,0,0,1},{1,0,1,0,0,1,0,1,0,0},{0,1,0,1,0,0,1,0,1,0},{0,0,1,0,1,0,0,1,0,1},{1,0,0,1,0,1,0,0,1,0},{0,1,0,0,1,0,1,0,0,1},{1,0,1,0,0,1,0,1,0,0},{0,1,0,1,0,0,1,0,1,0},{0,0,1,0,1,0,0,1,0,1},{1,0,0,1,0,1,0,0,1,0}}   Sometimes the number of data is too large to put the data in the main tex file. It would be better to import the data from external files. . $-1$ is a quadratic residue modulo $p$ if and only if $p\equiv 1\pmod{4}$ Text not very readable on different image backgrounds I am already a little bit familiar with Linux distros like Debian or Ubuntu (yeah, very similar) but I wanted to try Red Hat based - CentOS 6.2. I have installed it on my Windows 7 host in VirtualBox and tried to play with it a little. I have come across a small problem, namely: the default eth0 interface is down by default. I use the option with NAT (the virtual machine is 'behind' the host). Even if I bring the interface up with ifconfig eth0 up, it does not work right away. I get this after bringing the interface up: eth0      Link encap:Ethernet  HWaddr 08:00:27:0F:00:8A           inet6 addr: fe80::a00:27ff:fe0f:8a/64 Scope:Link           UP BROADCAST RUNNNING MULTICAST MTU:1500 Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:6 errors:0 dropped:0 overruns:0 carriers:0           collisions:0 txqueuelen:1000           RX bytes:0 (0.0 b)  TX bytes:468 (468.0 b)           Interrupt:19 Base address:0xd020  lo        Link encap:Local Loopback           inet addr:127.0.0.1  Mask:255.0.0.0           inet6 addr: ::1/128 Scope:Host           UP LOOPBACK RUNNING  MTU:16436  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)  virbr0    Link encap:Ethernet  HWaddr 52:54:00:75:C2:9B           inet addr:192.168.122.1  Bcast:192.168.122.255  Mask:255.255.255.0           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0 [root@centos ~]# _  What should be done more to configure the network on CentOS machine? From this paper:     Shouldn't $du$ be $dt$? And also how do you get from that line to the final result if $du$ is not $dt$? How do I make a 2D game resolution independent? I'm working on a simple 2D game. I've finished the mobile phone version.  However, my boss wants the game to works on his RT. I'm doing the "conversion" but my buttons are in the wrong places, because I hard-coded the screen size, like this:   texture = game.Content.Load&lt;Texture2D&gt;("StartScreen");  mainFrame = new Rectangle(0, 0, game.GraphicsDevice.Viewport.Width, game.GraphicsDevice.Viewport.Height);   // button definitions  startbrect = new Rectangle(300, 258, 88, 88);  startbtext = game.Content.Load&lt;Texture2D&gt;("bplay");   In this example, mainframe is fine, but startbrect isn't, because I defined the size to match a Windows phone's screen. How can I handle responsive design when all Windows 8 phones' screens are different? Is there a formula or macro to calculate each time the good size? There does not exist an entire function which satisfies $f({1\over n})={1\over 2^n}$? There does not exist an entire function which satisfies $f({1\over n})={1\over 2^n}$, what I tried is if possible then define $g(z)=f(z)-{1\over 2^{1\over z}}$ Then $g({1\over n})=0$ and so $g(z)$ is entire and its $0$ set has limit point in it and so $f(z)={1\over 2^{1\over z}}$ which is not analytic at $0$? Please help!  Edit: OOps! the way I defined $g(z)$ that is not entire! could any one give me hint? Fingerprint GUI not installing in Ubuntu 20.04 I'm trying to install fingerprint-gui on my Lenovo Ideapad 520 having Ubuntu 20.04 on which fingerprint isn't working for now. I tried going directly to Settings → Users → Automatic login and enabled the fingerprint login, but the error is:  Could not access any fingerprint readers Please contact your system administrator for help!  I also tried to install Fingerprint GUI: sudo apt-add-repository ppa:fingerprint/fingerprint-gui &amp;&amp; sudo apt-get update  sudo apt-get install libbsapi policykit-1-fingerprint-gui fingerprint-gui  but encountered this error: E: Package 'policykit-1-fingerprint-gui' has no installation candidate E: Package 'fingerprint-gui' has no installation candidate  What could be the problem here? Math.cos() gives wrong result Is there local file manipulation that's been done with JavaScript? I'm looking for a solution that can be accomplished with no install footprint like requiring .  Specifically, I'd like to read the contents from a file and write those contents to another file. At this point I'm not worried about gaining permissions and am just assuming I already have full permissions to these files. I have just bought a new computer and I have everything migrated over except for my Steam games.  I looked in Program Files/Steam/ and I found a folder full of the games I have downloaded, but I do not know if it is safe to just copy these folders from one computer to another (seeing as a lot of other applications will not work if you do this), or is there another recommended way?  I don't really feel like re-downloading all my games. I don't have the time nor bandwidth to download 20GB over a 1.5mbps connection.  Is it possible to contact Valve and get a disk with the games on it? Making a recursive CTE like query, but for many records Show that every irrational number in $\mathbb{R}$ is the limit of a   sequence of rational numbers. Every rational number in $\mathbb{R}$ is   the limit of a sequence of irrational numbers.   How can I prove this? Pull down resistor on logic gate input I would like to use a pull-down resistor on the input of a NOT logic gate. I am using a 5V microcontroller, and I want to ensure that the input of the gate will never be floating (eg. microcontroller damage).  General information:  The logic gate I am using is a HD74LS04 inverter whose datasheet can be found . I am testing the output by placing my positive multi-meter lead on R4 and the negative lead on GND. With the digital pin floating, the output of 1Y is 4.33V. This is the expected behavior.  The logic gate requires a minimum of 2.0V for Vih. If I understand this circuit correctly, I expect the voltage at pin 1A to be 3.76V since R2 and R3 will form a voltage divider. This value seems plenty to signify a 'high' in the logic gate.  R2 exists to protect the digital pin. Ideally, I would have liked R2 to be 1KΩ. Increasing the value of R2 means I have to increase the value of R3 to maintain the same voltage divider. During testing I found that if R3 was any value over 3.3KΩ, the pin 1A would not get pulled down all the way if I left the digital pin floating.   Tests: If I disconnect everything except GND and Vcc and place the positive lead of my multi-meter on pin 1A (now floating) and the negative lead to GND, I read 1.49V. Placing a pull-down resistor (R3) on pin 1A to GND with a value of 100Ω changes the reading to 0.02V. Increasing the resistor's value to 330Ω increases the reading to 0.07V. At the value I need, 3.3KΩ, the reading increases to 0.60V. Finally, changing the resistor's value to 1MΩ increases the reading to 1.47V and actually changes the output of pin 1Y to low.  The test that uses the 3.3KΩ resistor is concerning. The reading I took (0.60V) seems to be approaching the Vil maximum of the logic gate which is 0.80V.   Questions:  This must be a trivial question, but why does an R3 value of 3.3KΩ not pull pin 1A all the way to GND? Is there a formula for determining the correct pull-down resistor value? Other answers I found on here simply state 10KΩ as a 'good' value for a pull-up resistor. I'm not sure where that value comes from or if it is applicable to a pull-down resistor.         &ndash; Schematic created using   Edit: Although Ignacio's answer technically answers the question, I thought I would share some information I found for others who may come across this question.  User 'Papabravo' on the  states that the calculation for a pull down resistor can be calculated by taking the Vil (0.8V) and dividing it by the "standard TTL load" of 1.6mA. As Ignacio pointed out, my specific logic gate can source up to 0.4mA, so the calculation would be 0.8/0.0004A which equals 2KΩ. For safety, I performed the calculation at 0.5V in order to give myself some headroom.  Other Resources: change citation style ( [1-4] to [1]-[4], and [5, 8-9] to [5], [8]-[9] ) with natbib? I have spent a whole day trying to solve the following problem. Please help if you know how to do this.  I am using natbib (\usepackage[sort&amp;compress,square,comma]{natbib}), and my current citation style looks like [1-4], [5, 8-9].  What is the easiest way to change the citation style to [1]-[4] and [5],[8]-[9]? I have upgraded 14.04 to 16.04 . Now I am trying to open the gedit from terminal by passing the command:    sudo gedit /some/where/file.txt   but it is throwing an error stating that:    (gedit:2090): Gtk-WARNING : Calling Inhibit failed: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown:   The name org.gnome.SessionManager was not provided by any .service files**   However, it is opening the file. When I try to save any modification then it is showing this error after saving the file:    (gedit:2090): WARNING : Set document metadata failed: Setting attribute metadata::gedit-position not supported   I am not getting why this is happening in 16.04 only; it was not on 14.04. Introductory Calculus textbook for physics?