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  • How to stop input in Perl?

    - by user1472747
    First time poster and part time perl noobie. I'm making a reflex game. Here's the output - __________________________________________________________________________ Reflex game initiated. Press ENTER to begin the game, and then press ENTER after the asterisks are printed to measure your reflexes!. ************************* Your result: 0.285606 seconds. logout [Process completed] __________________________________________________________________________ There's one small problem though - There's 0-10 seconds (based on a random variable) after you press enter to start the game and before the stars are printed. During that time, if the player presses ENTER, it's logged as their reflex time. So I need a way to stop my code from reading their ENTER button before the stars are printed. The code - #!/usr/bin/perl use Time::HiRes qw(sleep); use Time::HiRes qw(gettimeofday); #random delay variable $random_number = rand(); print "Reflex game initiated. Press ENTER to begin the game, and then press ENTER after the asterisks are printed to measure your reflexes!.\n"; #begin button $begin = <>; #waits x milliseconds sleep(10*$random_number); #pre-game $start = [ Time::HiRes::gettimeofday() ]; print "\n****************************\n"; #user presses enter $stop = <>; #post game $elapsed = Time::HiRes::tv_interval($start); #delay time print print "Your result: ".$elapsed." seconds.\n";

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  • Some doubts about the use of usermod and groupmod command

    - by AndreaNobili
    I am not yet a true "Linux guy" and I have the following doubts about how exactly do the following shell procedure (a list of commands steps) founded in a tutorial that I am following (I want deeply understand what I am doing before do it): sudo passwd root then login again as root usermod -l miner pi usermod -m -d /home/miner miner groupmod -n miner pi exit So at the beginning it enable the root account and I have to login again in the system as root...this is perfectly clear for me. And now I have the followings doubts: 1) The usermod command: usermod -l miner pi usermod -m -d /home/miner miner Reading the official documentation of the usermod command I understand that this command modify the informations related to an existing account Reading the documentation it seems to me that the -l parmether modify the name of the user pi in miner and then the -m -d paramether move the contents of the old home directory to the new one (named miner) and use this new directory as home directory My doubt is: what exactly do the executions of these operation? I think that: Rename the existing pi user in miner Then move the content of the old home directory (the pi home directory? or what?) into a new directory (/home/miner) that now is the home directory for the miner user. Is it right? The the second doubt is related to this command groupmod -n miner pi It seems to me that change the group name from pi in miner But what exactly is a group in Linux and why is it used? Tnx

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  • After RAID failure SBS 2008 issues logging in and Exchange store does not mount

    - by Josh R
    today has been one of those days. Yesterday a hard drive in our Dell Poweredge 2900 server failed and the RAID array didn't degrade gracefully, so I called Dell (Server still under warranty) and got an engineer to work though the RAID issues with me. He was a nice guy but didn't do too much. We tried to put the RAID in a state where it was bootable and even though we only lost one disk there are still issues with the server. Once we got the server to boot there was an error message saying that the logonui.exe was corrupted and we needed to run chkdsk. I clicked through the error messages and the login screen never came up. So I power cycled the server and it chkdsk automatically but the login screen didn't appear. I tried safe mode, no difference there either. So the issues I am currently having are: 1) The server boots up, the loading windows screen comes up then it dumps me into a black screen where I can only see my mouse cursor. Ctrl+Esc doesn't work Ctrl+Alt+Del doesn't work 2) Some of the services come up: DHCP, DNS, DFS, and Print come up 3) The exchange information store and transport service don't start - I tried using mmc to connect to services.msc on the computer and start them but they throw an error message of "Can't start because group or dependency failed" Has anyone had a problem like this? Can anyone offer some guidance? Thanks a bunch!

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  • How to slave a 3.5" 500gb SATA external hard drive (Western Digital) to my Dell Inspiron laptop

    - by AJ HDD
    I have a 3.5" Western Digital My Book 500gb external hard drive. I gave it to a friend of mine, and he broke the USB port in it. I went to a nearby comp repair shop and had him solder the thing, and it didn't detect when it when I plugged it into my Dell Inspiron laptop. I recently saw about the 3.5" SATA to USB enclosure, so I went to check it. Strangely, when its placed in the enclosure, its not detecting in Windows. Also, when it was put as secondary (I'm guessing slave) to the shop fellow's desktop, it shows up in the BIOS and while starting, but then again doesn't show in Windows 7. The guy told me that I need to use a data recovery tool to get my data back. P.S. Whe WD hard drive doesnt have an OS, just data. So my question is: Can I slave the drive to my Dell laptop and try to recover the data, and if so how? I would really appreciate it any help, thanks in advance.

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  • access properties of current model in has_many declaration

    - by seth.vargo
    Hello, I didn't exactly know how to pose this question other than through example... I have a class we will call Foo. Foo :has_many Bar. Foo has a boolean attribute called randomize that determines the order of the the Bars in the :has_many relationship: class CreateFoo < ActiveRecord::Migration def self.up create_table :foos do |t| t.string :name t.boolean :randomize, :default => false end end end   class CreateBar < ActiveRecord::Migration def self.up create_table :bars do |t| t.string :name t.references :foo end end end   class Bar < ActiveRecord::Base belongs_to :foo end   class Foo < ActiveRecord::Base # this is the line that doesn't work has_many :bars, :order => self.randomize ? 'RAND()' : 'id' end How do I access properties of self in the has_many declaration? Things I've tried and failed: creating a method of Foo that returns the correct string creating a lambda function crying Is this possible? UPDATE The problem seems to be that the class in :has_many ISN'T of type Foo: undefined method `randomize' for #<Class:0x1076fbf78> is one of the errors I get. Note that its a general Class, not a Foo object... Why??

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  • Setting Up a Wordpress Function in theme's function.php File

    - by user1609391
    I am trying to create the below function in my theme's function.php file and call it from my taxonomy.php file via query_brands_geo('dealers', 'publish', '1', $taxtype, $geo, $brands); all variables are set in taxonomy.php. The below query works perfect if I put it directly in my taxonomy.php file. What am I missing to make this work as a function? As a function I get this error statement for argument repeated for 2-6: Warning: Missing argument 2 for query_brands_geo() function query_brands_geo($posttype, $poststatus, $paidvalue, $taxtype, $geo, $brands) { /* Custom Query for a brand/geo combination to display dealers with a certain brand and geography */ //Query only for brands/geography combo and paid dealers $wp_query = new WP_Query(); $args = array( 'post_type' => '$posttype', 'post_status' => array($poststatus), 'orderby' => 'rand', 'posts_per_page' => 30, 'meta_query' => array( array( 'key' => 'wpcf-paid', 'value' => array($paidvalue), 'compare' => 'IN', ) ), 'tax_query' => array( 'relation' => 'AND', array( 'taxonomy' => $taxtype, 'field' => 'slug', 'terms' => $geo ), array( 'taxonomy' => 'brands', 'field' => 'slug', 'terms' => $brands ) ) ); $wp_query->query($args); } add_action( 'after_setup_theme', 'query_brands_geo' );

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  • Is it possible to update Lenovo T500 hybrid graphics driver?

    - by Shiki
    Hope someone had the same problem before. My laptop comes with two video "cards". Intel MHD4500 and ATI Radeon HD3650 (mobility). I can switch between them with the "Lenovo Battery Manager" from the taskbar. All good, but Lenovo provides the driver for this. The problem with that driver is they are a bit old. (Both Intel and ATI). For example I doubt I have any gpu accel in flash, and I experience some problem with dual display setup, which the new ATI driver would solve. Basically I want to create a new driver (I read a topic where a guy said its possible... baaack then when I was searching for something else). One needs a special ATI driver creation utility or what... sorry I can't recall the name of it. Thanks in advance. (Ah yes I forgot: The OS is a Windows 7 x64 Ultimate.)

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  • c++ malloc segment fault

    - by chnet
    I have a problem about malloc(). It is wired. My code is in the following. I use random generator to generate elements for an array. The array is opened by malloc(). If the array size is smaller than 8192, it is OK. If the size is larger than 8192, it shows segment fault. void random_generator(int num, int * array) { srand((unsigned)time(0)); int random_integer; for(int index=0; index< num; index++){ random_integer = (rand()%10000)+1; *(array+index) = random_integer; cout << index << endl; } } int main() { int array_size = 10000; int *input_array; input_array = (int*) malloc((array_size)); random_generator(8192, input_array); // if the number is larger than 8192, segment fault free(input_array); }

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  • Who needs singletons?

    - by sexyprout
    Imagine you access your MySQL database via PDO. You got some functions, and in these functions, you need to access the database. The first thing I thought of is global, like: $db = new PDO('mysql:host=127.0.0.1;dbname=toto', 'root', 'pwd'); function some_function() { global $db; $db->query('...'); } But it's considered as a bad practice. So, after a little search, I ended up with the Singleton pattern, which "applies to situations in which there needs to be a single instance of a class." According to the example of the manual, we should do this: class Database { private static $instance, $db; private function __construct(){} static function singleton() { if(!isset(self::$instance)) self::$instance = new __CLASS__; return self:$instance; } function get() { if(!isset(self::$db)) self::$db = new PDO('mysql:host=127.0.0.1;dbname=toto', 'user', 'pwd') return self::$db; } } function some_function() { $db = Database::singleton(); $db->get()->query('...'); } some_function(); But I just can't understand why you need that big class when you can do it merely with: class Database { private static $db; private function __construct(){} static function get() { if(!isset(self::$rand)) self::$db = new PDO('mysql:host=127.0.0.1;dbname=toto', 'user', 'pwd'); return self::$db; } } function some_function() { Database::get()->query('...'); } some_function(); This last one works perfectly and I don't need to worry about $db anymore. But maybe I'm forgetting something. So, who's wrong, who's right?

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  • Optimization of SQL query regarding pair comparisons

    - by InfiniteSquirrel
    Hi, I'm working on a pair comparison site where a user loads a list of films and grades from another site. My site then picks two random movies and matches them against each other, the user selects the better of the two and a new pair is loaded. This gives a complete list of movies ordered by whichever is best. The database contains three tables; fm_film_data - this contains all imported movies fm_film_data(id int(11), imdb_id varchar(10), tmdb_id varchar(10), title varchar(255), original_title varchar(255), year year(4), director text, description text, poster_url varchar(255)) fm_films - this contains all information related to a user, what movies the user has seen, what grades the user has given, as well as information about each film's wins/losses for that user. fm_films(id int(11), user_id int(11), film_id int(11), grade int(11), wins int(11), losses int(11)) fm_log - this contains records of every duel that has occurred. fm_log(id int(11), user_id int(11), winner int(11), loser int(11)) To pick a pair to show the user, I've created a mySQL query that checks the log and picks a pair at random. SELECT pair.id1, pair.id2 FROM (SELECT part1.id AS id1, part2.id AS id2 FROM fm_films AS part1, fm_films AS part2 WHERE part1.id <> part2.id AND part1.user_id = [!!USERID!!] AND part2.user_id = [!!USERID!!]) AS pair LEFT JOIN (SELECT winner AS id1, loser AS id2 FROM fm_log WHERE fm_log.user_id = [!!USERID!!] UNION SELECT loser AS id1, winner AS id2 FROM fm_log WHERE fm_log.user_id = [!!USERID!!]) AS log ON pair.id1 = log.id1 AND pair.id2 = log.id2 WHERE log.id1 IS NULL ORDER BY RAND() LIMIT 1 This query takes some time to load, about 6 seconds in our tests with two users with about 800 grades each. I'm looking for a way to optimize this but still limit all duels to appear only once. The server runs MySQL version 5.0.90-community.

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  • quad sli with gtx 690 not working

    - by Moaadh
    I have two cards GTX 690 (dual core). I did the Sli successfully. Nvidia control panel acknowledges the two cards as quad Sli. However, the problem is that Windows 7 64-bit Ultimate is showing me the graph memory size as 4 GB while it is supposed to be 8 GB because of the Sli. Also the benchmark from all software is giving me a very low score compared to some other guy's benchmark on YouTube. It gives me a big headache. Does anyone know why this is happening? If so, how can I get Windows 7 to recognize all 8 GB of memory? Thanks for your help in advance. My computer specifications: (Processor: Intel Core i7-3930k @3.2GHz(12CPUs))--- (Memory: 65536 MB Ram 1866 MHz)-- (OS: Windows 7 Ultimate 64-bit)-- (OCZ 240GB as SSD PCIe drive for booting and storage disk)-- (DirextX version: DirectX 11)-- (VGA Card: 2 X EVGA GTX 690 Dual GPU. Each GPU is 2 GB, so total memory should be 8 GB.)-- (MotherBoard: ASUS Rampage IV Extreme)-- Others with lesser specifications get a 2500 score in heaven benchmark while I get 1501 as if it is one card.

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  • What is the --daemon option?

    - by Pascal Dimassimo
    I was installing Solr with Jetty using these instructions. Basically, those instructions made you download the Jetty startup script and copy it to /etc/init.d/jetty. But it was not working. Each time I was starting Jetty, I had a "FAILED" message and nothing to understand why it was happening. I decided to open up the /etc/init.d/jetty script to understand what was happening. I saw that this script was using start-stop-daemon to launch jetty. After a couple of time of debugging, I discovered that removing the --daemon option at the end of the start-stop-daemon call was fixing my problem. I did a couple of research and discovered that this guy had the same problem and resolved it like I did: my removing the --daemon option. What is weird is that the switch does not seem to be specific to start-stop-daemon, because it is not documented in the man page. Also, I've seen it used for other commands. So what is that --daemon option doing? And why removing it resolved my problem? Note that I am working on Ubuntu 10.04.2 LTS.

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  • Can't access certain web sites - reset router, any ideas?

    - by IniTech
    EDIT: This problem was resolved by my ISP - had to do with damaged fiber in one of their locations. Thanks to everyone that helped. Not sure if this is the right site (I'm a StackOverflow user) so I thought I'd give it a shot. I'm having trouble connecting to certain sites on any of the 3 machines that are on my LAN. The following sites are returning "Problem Loading Page - The connection has timed out" Sourceforge.net CNet.com Microsoft.com OpenDNS.com even my company's webiste I was worried about possible malware/virus, but I don't think that is the case (given the inability to access my company's site and the fact that all 3 machines are having the same issues.) I've tried with IE8, FF, and Chrome I have reset my router (WRT54G) and my machine(s) multiple times. EDIT: It is also worth noting that this page spins constantly and no avatars show up (I'm assuming it is trying to access gravatar.com with no success.) EDIT: I have the same issues directly connected to the modem. So, any router config is probably not the issue I'm a programmer, not a network guy - any ideas?

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  • CentOS server. What does it mean when the total used RAM does not equal the sum of RES?

    - by Michael Green
    I'm having a problem with a virtual hosted server running CentOS. In the past month a process (java based) that had been running fine started having problems getting memory when the JVM was started. One strange thing I've noticed is that when I start the process, the PID says it is using 470mb of RAM while the 'used' memory immediately drops by over a 1GB. If I run 'top', the total RES used across all processes falls short of the 'used' listed at the top by almost 700mb. The support person says this means I have a memory leak with my process. I don't know what to believe because I would expect a memory leak to simply waste the memory the process is allocated not to consume additional memory that doesn't show up using 'top'. I'm a developer and not a server guy so I'm appealing to the experts. To me, if the total RES memory doesn't add up to the total 'used' it indicates that something is wrong with my virtual server set-up. Would you also suspect a memory leaking java process in this case? If I use free before: total used free shared buffers cached Mem: 2097152 149264 1947888 0 0 0 -/+ buffers/cache: 149264 1947888 Swap: 0 0 0 free after: total used free shared buffers cached Mem: 2097152 1094116 1003036 0 0 0 -/+ buffers/cache: 1094116 1003036 Swap: 0 0 0 So it looks as though the process is using (or causing to be used) nearly 1GB of RAM. Since the process (based on top is only using 452mb, does that mean that the kernal is all of a sudden using an additional 500mb?

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  • PHP hashing function not working properly

    - by Jordan Foreman
    So I read a quick PHP login system securing article, and was trying to sort of duplicate their hashing method, and during testing, am not getting the proper output. Here is my code: function decryptPassword($pw, $salt){ $hash = hash('sha256', $salt . hash('sha256', $pw)); return $hash; } function encryptPassword($pw){ $hash = hash('sha256', $pw); $salt = substr(md5(uniqid(rand(), true)), 0, 3); $hash = hash('sha265', $salt . $hash); return array( 'salt' => $salt, 'hash' => $hash ); } And here is my testing code: $pw = $_GET['pw']; $enc = encryptPassword($pw); $hash = $enc['hash']; $salt = $enc['salt']; echo 'Pass: ' . $pw . '<br />'; echo 'Hash: ' . $hash . '<br />'; echo 'Salt: ' . $salt . '<br />'; echo 'Decrypt: ' . decryptPassword($hash, $salt); Now, the output of this should be pretty obvious, but unfortunately, the $hash variable always comes out empty! I'm trying to figure out what the problem could be, and my only guess would be the second $hash assignment line in the encryptPassword(..) function. After a little testing, I've determined that the first assignment works smoothly, but the second does not. Any suggestions? Thanks SO!

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  • Better way to compare neighboring cells in matrix

    - by HyperCube
    Suppose I have a matrix of size 100x100 and I would like to compare each pixel to its direct neighbor (left, upper, right, lower) and then do some operations on the current matrix or a new one of the same size. A sample code in Python/Numpy could look like the following: (the comparison 0.5 has no meaning, I just want to give a working example for some operation while comparing the neighbors) import numpy as np my_matrix = np.random.rand(100,100) new_matrix = np.array((100,100)) my_range = np.arange(1,99) for i in my_range: for j in my_range: if my_matrix[i,j+1] > 0.5: new_matrix[i,j+1] = 1 if my_matrix[i,j-1] > 0.5: new_matrix[i,j-1] = 1 if my_matrix[i+1,j] > 0.5: new_matrix[i+1,j] = 1 if my_matrix[i-1,j] > 0.5: new_matrix[i-1,j] = 1 if my_matrix[i+1,j+1] > 0.5: new_matrix[i+1,j+1] = 1 if my_matrix[i+1,j-1] > 0.5: new_matrix[i+1,j-1] = 1 if my_matrix[i-1,j+1] > 0.5: new_matrix[i-1,j+1] = 1 This can get really nasty if I want to step into one neighboring cell and start from it to do a similar task... Do you have some suggestions how this can be done in a more efficient manner? Is this even possible?

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  • Include php code within echo from a random text

    - by lisa
    I want to display a php code at random and so for I have <?php // load the file that contain thecode $adfile = "code.txt"; $ads = array(); // one line per code $fh = fopen($adfile, "r"); while(!feof($fh)) { $line = fgets($fh, 10240); $line = trim($line); if($line != "") { $ads[] = $line; } } // randomly pick an code $num = count($ads); $idx = rand(0, $num-1); echo $ads[$idx]; ?> The code.txt has lines like <?php print insert_proplayer( array( "width" => "600", "height" => "400" ), "http://www.youtube.com/watch?v=xnPCpCVepCg"); ?> Proplayer is a wordpress plugin that displays a video. The codes in code.txt work well, but not when I use the pick line from code.txt. Instead of the full php line I get: "width" => "600", "height" => "400" ), "http://www.youtube.com/watch?v=xnPCpCVepCg"); ?> How can I make the echo show the php code, rather than a txt version of the php code?

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  • Does anyone know the touchpad disabling driver for Dell xps 14?

    - by rkar
    I accidentally deleted my Dell xps 14 touch pad disabling driver and I don't know where to find it and reinstall it. I have already tried Dell support and without luck (I don't want to install something that I don't know). Would anyone please send me the link to that driver To clarify: There is this Fn shortcut key used to disable/enable touch pad in Dell xps14 and when press it orange light on touch pad will lit and touch pad will stop working. But after deleting the driver that responsible for that function,it stopped working. My service center is almost 600 miles away and he said that he forgot to add it last time he fix my laptop. Since the internet connection at his place is slow,he can't send me from mail either.So can anyone send me the link for that driver. Since I don't really know about drivers it would be really nice if some one show me the driver name or link. Sorry,here is my laptop service tag "C37KWL1".I don't know how to find the specific driver for that function key.My dell has a short cut for disabling touchpad with picture on it along with the other multimedia short cut key with picture. since xps 15 and 17 have seperated touch key instead of on function keys mine have to choose function key or multimedia key through setting.To be honest my service center tech guy forgot to install it when he repair it and can't send me the file(which is about over 20mb or something according to him)for some reason.All i need is that particular file.

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  • Replace duplicate values in array with new randomly generated values

    - by RussellDias
    I have below a function (created by Gordon in a previous question that went unanswered) that creates an array with n amount of values. The sum of the array is equal to $max. function randomDistinctPartition($n, $max) { $partition= array(); for($i=1; $i < $n; $i++) { $maxSingleNumber = $max - $n; $partition[] = $number = rand(1, $maxSingleNumber); } $max -= $number; } $partition[] = $max; return $partition; } For example: If I set $n = 4 and $max = 30. Then I should get the following. array(5, 7, 10, 8); However, this function does not take into account duplicates and 0s. What I would like - and have been trying to accomplish - is to generate an array with unique numbers that add up to my predetermined variable $max. No Duplicate numbers and No 0 and/or negative integers.

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  • How do I declare and initialize a 2d int vector in C++?

    - by FrankTheTank
    I'm trying to do something like: #include <iostream> #include <vector> #include <ctime> class Clickomania { public: Clickomania(); std::vector<std::vector<int> > board; bool move(int, int); bool isSolved(); void print(); void pushDown(); }; Clickomania::Clickomania() : board(12, std::vector<int>(8,0)) { srand((unsigned)time(0)); for(int i = 0; i < 12; i++) { for(int j = 0; j < 8; j++) { int color = (rand() % 6) + 1; board[i][j] = color; } } } However, apparently I can't initialize the "board" vector of vectors this way. How can I create a public member of a 2d vector type and initialize it properly?

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  • c++ malloc segmentation fault

    - by chnet
    I have a problem about malloc(). It is weird. My code is in the following. I use random generator to generate elements for an array. The array is opened by malloc(). If the array size is smaller than 8192, it is OK. If the size is larger than 8192, it shows segment fault. void random_generator(int num, int * array) { srand((unsigned)time(0)); int random_integer; for(int index=0; index< num; index++){ random_integer = (rand()%10000)+1; *(array+index) = random_integer; cout << index << endl; } } int main() { int array_size = 10000; int *input_array; input_array = (int*) malloc((array_size)); random_generator(8192, input_array); // if the number is larger than 8192, segment fault free(input_array); }

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  • different user group can not upload file in the server

    - by Dallal
    I have a CentOS server running in Thailand, and I'm in Canada. The guy at the computer center who set up the server for me doesn't really understand much about linux and left me off an issue to solve myself. I just moved from Mac Server to Linux server, and the first thing I'm facing a problem now is `file name` has failed to upload due to an error The uploaded file could not be moved to `location name` So what happen is that I knew from my experiences of these problem is all about permissions. So I go ahead and checked on my whole folder and found that everything in the folder permission is like myusername mygroupname then I checked the httpd file in the server and it is default to apache apache. My question is that how can I make my user to be in the same group with apache group so that I don't have to have any problem about uploading, changing data in my file....? But without having to affect other user in the same server. I'm holding Administrator account, but not root account, but I can change stuff on the server root no problem. When I was with godaddy.com there never been any problem about the permission and I wish I know how they configure that :(

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  • Network outage caused by SMC8013WG Cable Modem/Router ?

    - by mkocubinski
    At work, we have a basic Class C Network. The gateway/router is a SMC8013WG (stock comcast commercial cable modem), and simple unmanaged switch (HP Pro Curve 1400 24G). The SMC8013WG is our default gateway as well as DHCP server. Periodically, I'd say almost every other day.. the entire network will just stop responding. I won't be able to ping/see the gateway, any computers on our local network, or anything on the internet. The only way to fix this is to unplug the Comcast cable modem, wait, and plug back in. This unfailingly fixes the problem. But this doesn't make much sense to me.. shouldn't the network still be fine locally, since everything is plugged into the switch anyway? Why would resetting the router fix this? Can anyone suggest anything to check to in order to narrow this problem down? Just to be clear.. here is the basic topology: { Internet } -- (12.345.67.89) Comcast Cable Modem (192.168.1.1) -- Switch -- 192.168.1.2-254 P.S. Our IT guy is in about 3 hours a day every other week or so, so.. we're kind of on our own most of the time.

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  • Matlab Coin Toss Simulation

    - by user1772959
    I have to write some code in Matlab that simulates tossing a coin 150 times. I have to count how many times the coin lands on heads and create a vector that gives a running percentage of the heads. Then I have to make a table of the number of trials, random 'flips", and the running percentages of heads. I assume random "flips" means heads or tails for that trial. I also have to create a line graph with trials on the x-axis and probabilities (percentages) on the y-axis. I'm assuming the percentages are just the percentage of getting heads. Sorry if this post was long. I figure giving the details now will make it easier to see what I was trying to do with the code. I didn't create the table or plot yet because I'm not even sure how to code for the actual problem. NUM_TRIALS = 150; trials = 1:NUM_TRIALS; heads = 0; t = rand(NUM_TRIALS,1); for i = trials if (t < 0.5) heads = heads + 1; end z = zeros(NUM_TRIALS,1); percent_h = heads/trials; end

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  • Agile web development with rails

    - by Steve
    Hi.. This code is from the agile web development with rails book.. I don't understand this part of the code... User is a model which has name,hashed_password,salt as its fields. But in the code they are mentioning about password and password confirmation, while there are no such fields in the model. Model has only hashed_password. I am sure mistake is with me. Please clear this for me :) User Model has name,hashed_password,salt. All the fields are strings require 'digest/sha1' class User < ActiveRecord::Base validates_presence_of :name validates_uniqueness_of :name attr_accessor :password_confirmation validates_confirmation_of :password validate :password_non_blank def self.authenticate(name, password) user = self.find_by_name(name) if user expected_password = encrypted_password(password, user.salt) if user.hashed_password != expected_password user = nil end end user end def password @password end def password=(pwd) @password = pwd return if pwd.blank? create_new_salt self.hashed_password = User.encrypted_password(self.password, self.salt) end private def password_non_blank errors.add(:password,"Missing password")if hashed_password.blank? end def create_new_salt self.salt = self.object_id.to_s + rand.to_s end def self.encrypted_password(password, salt) string_to_hash = password + "wibble" + salt Digest::SHA1.hexdigest(string_to_hash) end end

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