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  • Creating Ubuntu Browser App Frames

    - by user73006
    After watching the video i am inspired to create one browser but stuck at one place, could you please help me with this. Requirement = - Like you displayed in your Video i wan create Multiple Buttons in my Toolbar which will open Second ToolBar or Popup Window. - From that Pop Window i wanted to Select Specific Button Which will open My Required Browser. Question - - As displayed in your Video i create new BUtton and If i try to open new link using that it works but now i want to display tool bar or Popup window once any one click on that button, how can i do that.The Second Tool Bar Need to be Activated only after clicking on that button. Things i Tried - - As per my understanding i create Second Toolbar and on that tool bar i have created Button, now i wan know how do i link that tool bar with my Browser Toolbar button. - I tried that by passing Signal Property in Second Toolbar in Quickly but something is missing. MY Code class TvbrowserWindow(Window): gtype_name = "TvbrowserWindow" def finish_initializing(self, builder): # pylint: disable=E1002 """Set up the main window""" super(TvbrowserWindow, self).finish_initializing(builder) self.AboutDialog = AboutTvbrowserDialog self.PreferencesDialog = PreferencesTvbrowserDialog # Code for other initialization actions should be added here. self.refreshbutton=self.builder.get_object("refreshbutton") self.SONY=self.builder.get_object("SONY") self.urlentry=self.builder.get_object("urlentry") self.scrolledwindow1=self.builder.get_object("scrolledwindow1") self.webview = WebKit.WebView() self.scrolledwindow1.add(self.webview) self.webview.show() def on_refreshbutton_clicked(self, widget): print "refresh" def on_urlentry_activate(self, widget): url = widget.get_text() print url self.webview.open(url)

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  • C# Threading Background Process - Programming - How to?

    - by Magic
    Hello...I have been given the horrible task of doing this. Launch the website Take a screenshot Fill in the form details, click on Next Take a screenshot ... ... ... Rinse. Repeat. Now, with various combinations, this comes up to 300 screenshots. And I have to do this for 4 different browsers. Chrome, Firefox, IE 6 and IE 7. I cannot use tools which will capture the screenshot and store them, such as, SnagIT. I need to take a screenshot, copy it to a Word Document and take the second screenshot and take it to a Word Document. I thought, I will write a tiny utility which will help me do this. Here is the requirement spec that I put up for it - An executable which once launched seats itself in the System Tray. While it is active, all instances of Key Press (Print Scrn), it should write the contents to a Word Document as defined (either a default path or a user defined one). Save the document periodically. Now, my question is - if I am going to develop this using C# (Winforms application), how do I go about doing this. I can do a fair bit of C# programming and I am willing to learn. But I am not able to locate the references for how to do a background process so that it runs in the background. And while it runs, it has to capture the Print Scrn command. Can you folks point me to the right material where I can learn this? Theoretical references should suffice. But if there are practical references, then nothing like it. Thanks!

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  • How to Integrate Dropbox with Pages, Keynote, and Numbers on iPad

    - by The Geek
    The iWork apps are some of the best apps on the iPad, and each show just how powerful a touchscreen device can be with the most basic of computing functions. In fact, there’s not much to dislike about the iWork apps, except for one thing: importing and exporting files. You can open documents from email attachments, download them from websites, or import them from other apps like Dropbox. Once you’ve opened your file in Pages, Keynote, or Numbers on iPad, though, you can only send it via email, upload it to a WebDAV server or Apple’s iDisk service, or wait to sync it with iTunes on your computer. Most other iOS office apps don’t offer nearly as many features as the iWork apps, but they do offer deep integration with Dropbox which makes it easy to view and edit your documents no matter where you are. Dropbox is the most popular file sync and sharing solution, and makes it absolutely painless to share folders with anyone around the world and keep your computers in sync. That is, computers and applications that integrate with Dropbox. However, you don’t need to give up on using Dropbox with iWork apps on iPad. Today we’re going to look at how you can enable WebDAV compatibility on your Dropbox account to let Pages integrate nearly the whole way with Dropbox. It’s not a perfect solution, but it’s much better than the default setup. So let’s get started Latest Features How-To Geek ETC How to Integrate Dropbox with Pages, Keynote, and Numbers on iPad RGB? CMYK? Alpha? What Are Image Channels and What Do They Mean? How to Recover that Photo, Picture or File You Deleted Accidentally How To Colorize Black and White Vintage Photographs in Photoshop How To Get SSH Command-Line Access to Windows 7 Using Cygwin The How-To Geek Video Guide to Using Windows 7 Speech Recognition Stylebot Customizes Web Pages in Chrome, Now Has Downloadable Styles Blackberry, Dell, Apple, and Motorola Tablets Compared [Infographic] Encrypt Your Google Search Queries Vintage Posters Showcase the History of Tech Advertising Google Cloud Print Extension Lets You Print Doc/PDF/Txt Files from Web Sites Hack a $10 Flashlight into an Ultra-bright Premium One

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  • Use crontab scheduling java application problem occurs

    - by koma
    The main method to start the java application. The main method initialize the log, and then determine whether the process is running. Every 10 minutes, scheduled to run through the linux crontab. Able to determine that the 10 minutes of this program must end. Under normal circumstances, will print the following log The beginning of the implementation of 10 minutes The end of the 10 minutes of normal The beginning of the implementation of 20 minutes The end of the 20 minutes of normal The beginning of the implementation of 30 minutes The end of the 30 minutes of normal ..... But now this situation: The beginning of the implementation of 10 minutes The end of the 10 minutes of normal Execution starts in 30 minutes, but detected already have a process in operation, the program exits. Start the execution of 40 points, but detected already have a process in operation, the program exits. ..... Very strange 20-minute log does not print, but the 20-minute program has been launched by the ps-ef | grep java view java thread, found in a 20-minute thread is locked. But why not see the log Check the linux dispatch log, not see scheduling a 20-minute log.

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  • Add & Show data in Java ArrayList [closed]

    - by Kaidul Islam Sazal
    I have a class inside a main class : static class Graph{ static int u, v, cost; } I have instantiated an arraylist of the class: static List<Graph> g = new ArrayList<Graph>(); And I insert several values into the arraylist like this: Scanner input = new Scanner(System.in); for (int i = 0; i < edge_no; i++) { Graph e = new Graph(); e.u = input.nextInt(); e.v = input.nextInt(); e.cost = input.nextInt(); g.add(e); } And I print it like this: for (int i = 0; i < edge_no; i++) { System.out.println(g.get(i).u + " " + g.get(i).v + " " + g.get(i).cost); } But the problem is that, when I print it, only the last value is shown all the time.It seems that, all the previous values are over-written with it. Input : 1 2 5 1 3 8 2 3 9 Output: 2 3 9 2 3 9 2 3 9 Expected output is just like the input.But I can't fix the problem as I am novice in java.

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  • Create Your Own Quick Calculator Function for the Terminal

    - by The Geek
    If you’re anything like me, you’ve always got a Terminal window open, and you probably have even assigned a hotkey to bring it up anytime. So why open up the boring calculator when you can solve equations right there on the command line? This is a simple method for creating a calculator using the built-in function support in the Bash shell. Essentially all we’re doing is assigning the question mark to run the bc command with whatever arguments you type after it. Latest Features How-To Geek ETC RGB? CMYK? Alpha? What Are Image Channels and What Do They Mean? How to Recover that Photo, Picture or File You Deleted Accidentally How To Colorize Black and White Vintage Photographs in Photoshop How To Get SSH Command-Line Access to Windows 7 Using Cygwin The How-To Geek Video Guide to Using Windows 7 Speech Recognition How To Create Your Own Custom ASCII Art from Any Image Vintage Posters Showcase the History of Tech Advertising Google Cloud Print Extension Lets You Print Doc/PDF/Txt Files from Web Sites Hack a $10 Flashlight into an Ultra-bright Premium One Firefox Personas Arrive on Firefox Mobile Focus Booster Is a Sleek and Free Productivity Timer What is the Internet? From the Today Show January 1994 [Historical Video]

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  • How do I list all the relation variables and debug them interactively?

    - by mfisch
    I'm writing a charm that requires a mysql database, I found from looking at other charms that this (below) is how I get the info about the database: user=`relation-get user` password=`relation-get password` mysqlhost=`relation-get private-address` But I just found that from reading the wordpress charm example, is there a way to show all the relation variables that I can use? Also, while debugging my db-relation-changed script, I wanted to ssh into my host and interactively run those commands, for example relation-get user, but it didn't work. I resorted to having to restart everything and use juju log to print them out. This wasted a lot of time. Is there a way to print out these relations, either from my dev box or from the instance running my charm? (Below is what happens when I tried to interactively run relation-get): ubuntu@mfisch-local-tracks-0:~$ relation-get user usage: relation-get [-h] [-o OUTPUT] [-s SOCKET] [--client-id CLIENT_ID] [--format FORMAT] [--log-file FILE] [--log-level CRITICAL|DEBUG|INFO|ERROR|WARNING] [-r RELATION ID] [settings_name] [unit_name] No JUJU_AGENT_SOCKET/-s option found I tried juju debug-hooks tracks/0 -e local, that dropped me into a shell and relation-get still failed.

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  • The better way to ask for input?

    - by Skippy
    I am wondering which is the best way to go with java code. I need to create a class with simple prompts for input.. I have tried using both classes and cannot work out the particular benefits for each. Is this because I am still in the early stages of programming or are there situations that will occur as it becomes more complex?? import java.util.Scanner; public class myClass { Scanner stdin = new Scanner(System.in); public String getInput(String prompt) { System.out.print(prompt); return stdin.nextLine(); } ... or import java.io.*; public class myClass { public static void main(String[] args) throws IOException { BufferedReader stdin = new BufferedReader (new InputStreamReader (System.in)); System.out.print("Input something: "); String name = stdin.readLine(); I know these examples are showing different methods within these classes, but thought this might serve well for the discussion. I'm really not sure which site is the best to ask this on.

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  • Recursive function with for loop python

    - by user134743
    I have a question that should not be too hard but it has been bugging me for a long time. I am trying to write a function that searches in a directory that has different folders for all files that have the extension jpg and which size is bigger than 0. It then should print the sum of the size of the files that are in these categories. What I am doing right now is def myFuntion(myPath, fileSize): for myfile in glob.glob(myPath): if os.path.isdir(myFile): myFunction(myFile, fileSize) if (fnmatch.fnmatch(myFile, '*.jpg')): if (os.path.getsize(myFile) > 1): fileSize = fileSize + os.path.getsize(myFile) print "totalSize: " + str(fileSize) THis is not giving me the right result. It sums the sizes of the files of one directory but it does not keep suming the rest. For example if I have these paths C:/trial/trial1/trial11/pic.jpg C:/trial/trial1/trial11/pic1.jpg C:/trial/trial1/trial11/pic2.jpg and C:/trial/trial2/trial11/pic.jpg C:/trial/trial2/trial11/pic1.jpg C:/trial/trial2/trial11/pic2.jpg I will get the sum of the first three and the the size of the last 3 but I won´t get the size of the 6 together, if that makes sense. Thank you so much for your help!

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  • How to match responses from a server with their corresponding requests? [closed]

    - by Deele
    There is a server that responds to requests on a socket. The client has functions to emit requests and functions to handle responses from the server. The problem is that the request sending function and the response handling function are two unrelated functions. Given a server response X, how can I know whether it's a response to request X or some other request Y? I would like to make a construct that would ensure that response X is definitely the answer to request X and also to make a function requestX() that returns response X and not some other response Y. This question is mostly about the general programming approach and not about any specific language construct. Preferably, though, the answer would involve Ruby, TCP sockets, and PHP. My code so far: require 'socket' class TheConnection def initialize(config) @config = config end def send(s) toConsole("--> #{s}") @conn.send "#{s}\n", 0 end def connect() # Connect to the server begin @conn = TCPSocket.open(@config['server'], @config['port']) rescue Interrupt rescue Exception => detail toConsole('Exception: ' + detail.message()) print detail.backtrace.join('\n') retry end end def getSpecificAnswer(input) send "GET #{input}" end def handle_server_input(s) case s.strip when /^Hello. (.*)$/i toConsole "[ Server says hello ]" send "Hello to you too! #{$1}" else toConsole(s) end end def main_loop() while true ready = select([@conn, $stdin], nil, nil, nil) next if !ready for s in ready[0] if s == $stdin then return if $stdin.eof s = $stdin.gets send s elsif s == @conn then return if @conn.eof s = @conn.gets handle_server_input(s) end end end end def toConsole(msg) t = Time.new puts t.strftime("[%H:%M:%S]") + ' ' + msg end end @config = Hash[ 'server'=>'test.server.com', 'port'=>'2020' ] $conn = TheConnection.new(@config) $conn.connect() $conn.getSpecificAnswer('itemsX') begin $conn.main_loop() rescue Interrupt rescue Exception => detail $conn.toConsole('Exception: ' + detail.message()) print detail.backtrace.join('\n') retry end

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  • Why is the remove function not working for hashmaps? [migrated]

    - by John Marston
    I am working on a simple project that obtains data from an input file, gets what it needs and prints it to a file. I am basically getting word frequency so each key is a string and the value is its frequency in the document. The problem however, is that I need to print out these values to a file in descending order of frequency. After making my hashmap, this is the part of my program that sorts it and writes it to a file. //Hashmap I create Map<String, Integer> map = new ConcurrentHashMap<String, Integer>(); //function to sort hashmap while (map.isEmpty() == false){ for (Entry<String, Integer> entry: map.entrySet()){ if (entry.getValue() > valueMax){ max = entry.getKey(); System.out.println("max: " + max); valueMax = entry.getValue(); System.out.println("value: " + valueMax); } } map.remove(max); out.write(max + "\t" + valueMax + "\n"); System.out.println(max + "\t" + valueMax); } When I run this i get: t 9 t 9 t 9 t 9 t 9 .... so it appears the remove function is not working as it keeps getting the same value. I'm thinking i have an issue with a scope rule or I just don't understand hashmaps very well. If anyone knows of a better way to sort a hashmap and print it, I would welcome a suggestion. thanks

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  • What design pattern (in python) to use for properly seperate runtime infos with core code?

    - by user1824372
    I am not sure if this is a clear question. I work on a python project that is based on terminal(console), for which I am planning to implement a GUI. I am not major in CS so I really have no idea about how to effectively design a message system such that: in console, it provide nice look info when runtime. in GUI, it is directed to a certain widget, let's say, a text label, or a bottom bar, or a hide-able frame. Do you have any suggestions? Currently, I am using print function to provide essential informations on stdout during runtime. So a lot of print .... are distributed here and there among the code. I am thinking to use macro-like variables such as 'FILE_NOT_EXTIS_MESSAGE' for printing, and define the variables in one file. Is this a standard way that people always do? How about I introduce a logging system? In sum, I am ask for a pattern that people are commonly using for handling of screen output information with high effectiveness and adaptivity.

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  • Check Checkboxes dynamically

    - by Selom
    Hi, ive been dealing with this for some time now and need your help. well I have an array $arrayAmenities which contains a combination of the following data based on what is fetched from the database: Air Conditioned Bar Brunch Party Room Tea Room Terrace Valet I would like the application to dynamically check the following set of checkboxes based on the data contained in the array. With my code only one checkbox is checked based on the first data contained in the array. Can you please tell what Im missing? Thanks for answering. code: //get amenities one by one in order to set the checkboxes $arrayAmenities = explode(',', $rest_amenities ); $i=0; while(count($arrayAmenities) > $i) { var_dump($arrayAmenities[$i]); switch($arrayAmenities[$i]) { case 'Air Conditioned': $checkedAir = 'checked=true'; break; case 'Bar': $checkedBar = 'checked=true'; break; case 'Brunch': $checkedBru = 'checked=true'; break; case 'Party Room'; $checkedPar = 'checked=true'; break; } $i+=1; } } checkboxes <table cellpadding="0" cellspacing="0" style="font-size:10px"> <tr> <td style="border-top:1px solid #CCC;border-right:1px solid #CCC;border-left:1px solid #CCC; padding-left:5px ">Air Conditioned <input type="checkbox" name="air_cond" <?php print $checkedAir;?> value="Air Conditioned"></td> <td style="padding-left:10px; border-top:1px solid #CCC;border-right:1px solid #CCC;">Bar <input type="checkbox" name="bar" value="Bar" <?php print $checkedBar;?>></td> <td style="padding-left:10px; border-top:1px solid #CCC;border-right:1px solid #CCC; ">Brunch <input type="checkbox" name="brunch" value="Brunch" <?php print $checkedBru;?>></td> </tr> <tr> <td style="border-top:1px solid #CCC;border-right:1px solid #CCC; border-bottom:1px solid #CCC; border-left:1px solid #CCC; padding-left:5px">Party Room <input <?php print $checkedPar;?> type="checkbox" name="party_room" value="Party Room" ></td> <td style="padding-left:10px; border-top:1px solid #CCC;border-right:1px solid #CCC; border-bottom:1px solid #CCC;">Tea Room <input type="checkbox" name="tea_room" value="Tea Room" ></td> <td style="padding-left:10px; border-top:1px solid #CCC;border-right:1px solid #CCC; border-bottom:1px solid #CCC;">Terrace <input type="checkbox" name="terrace" value="Terrace"></td> </tr> <tr> <td colspan="3" style="border-bottom:1px solid #CCC; border-left:1px solid #CCC; border-right:1px solid #CCC; padding-left:5px">Valet <input type="checkbox" name="valet" value="Valet" ></td> </tr> </table>

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  • search a collection for a specific keyword

    - by icelated
    What i want to do is search a hashset with a keyword.. I have 3 classes... main() Library Item(CD, DVD,Book classes) In library i am trying to do my search of the items in the hashsets.. In Item class is where i have the getKeywords function.. here is the Items class... import java.io.PrintStream; import java.util.Collection; import java.util.*; class Item { private String title; private String [] keywords; public String toString() { String line1 = "title: " + title + "\n" + "keywords: " + Arrays.toString(keywords); return line1; } public void print() { System.out.println(toString()); } public Item() { } public Item(String theTitle, String... theKeyword) { this.title = theTitle; this.keywords = theKeyword; } public String getTitle() { return title; } public String [] getKeywords() { return keywords; } } class CD extends Item { private String artist; private String [] members; // private String [] keywords; private int number; public CD(String theTitle, String theBand, int Snumber, String... keywords) { super(theTitle, keywords); this.artist = theBand; this.number = Snumber; // this.keywords = keywords; } public void addband(String... member) { this.members = member; } public String getArtist() { return artist; } public String [] getMembers() { return members; } // public String [] getKeywords() // { // return keywords; //} public String toString() { return "-Music-" + "\n" + "band: " + artist + "\n" + "# songs: " + number + "\n" + "members: " + Arrays.toString(members) + "\n" + super.toString() // + "keywords: " + Arrays.toString(keywords) + "\n" + "\n" ; } public void print() { System.out.println(toString()); } } class DVD extends Item { private String director; private String [] cast; private int scenes; // private String [] keywords; public DVD(String theTitle, String theDirector, int nScenes, String... keywords) { super(theTitle, keywords); this.director = theDirector; this.scenes = nScenes; // this.keywords = keywords; } public void addmoviecast(String... members) { this.cast = members; } public String [] getCast() { return cast; } public String getDirector() { return director; } // public String [] getKeywords() // { // return keywords; // } public String toString() { return "-Movie-" + "\n" + "director: " + director + "\n" + "# scenes: " + scenes + "\n" + "cast: " + Arrays.toString(cast) + "\n" + super.toString() // + "keywords: " + Arrays.toString(keywords) + "\n" + "\n" ; } public void print() { System.out.println(toString()); } } class Book extends Item { private String author; private int pages; public Book(String theTitle, String theAuthor, int nPages, String... keywords) { super(theTitle, keywords); this.author = theAuthor; this.pages = nPages; // this.keywords = keywords; } public String getAuthor() { return author; } //public String [] getKeywords() // { // return keywords; //} public void print() { System.out.println(toString()); } public String toString() { return "-Book-" + "\n" + "Author: " + author + "\n" + "# pages " + pages + "\n" + super.toString() // + "keywords: " + Arrays.toString(keywords) + "\n" + "\n" ; } } I hope i didnt confuse you? I need help with the itemsForKeyword(String keyword) function.. the first keyword being passed in is "science fiction" and i want to search the keywords in the sets and return the matches.. What am i doing so wrong? Thank you

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  • How should I clean up hung grandchild processes when an alarm trips in Perl?

    - by brian d foy
    I have a parallelized automation script which needs to call many other scripts, some of which hang because they (incorrectly) wait for standard input. That's not a big deal because I catch those with alarm. The trick is to shut down those hung grandchild processes when the child shuts down. I thought various incantations of SIGCHLD, waiting, and process groups could do the trick, but they all block and the grandchildren aren't reaped. My solution, which works, just doesn't seem like it is the right solution. I'm not especially interested in the Windows solution just yet, but I'll eventually need that too. Mine only works for Unix, which is fine for now. I wrote a small script that takes the number of simultaneous parallel children to run and the total number of forks: $ fork_bomb <parallel jobs> <number of forks> $ fork_bomb 8 500 This will probably hit the per-user process limit within a couple of minutes. Many solutions I've found just tell you to increase the per-user process limit, but I need this to run about 300,000 times, so that isn't going to work. Similarly, suggestions to re-exec and so on to clear the process table aren't what I need. I'd like to actually fix the problem instead of slapping duct tape over it. I crawl the process table looking for the child processes and shut down the hung processes individually in the SIGALRM handler, which needs to die because the rest of real code has no hope of success after that. The kludgey crawl through the process table doesn't bother me from a performance perspective, but I wouldn't mind not doing it: use Parallel::ForkManager; use Proc::ProcessTable; my $pm = Parallel::ForkManager->new( $ARGV[0] ); my $alarm_sub = sub { kill 9, map { $_->{pid} } grep { $_->{ppid} == $$ } @{ Proc::ProcessTable->new->table }; die "Alarm rang for $$!\n"; }; foreach ( 0 .. $ARGV[1] ) { print "."; print "\n" unless $count++ % 50; my $pid = $pm->start and next; local $SIG{ALRM} = $alarm_sub; eval { alarm( 2 ); system "$^X -le '<STDIN>'"; # this will hang alarm( 0 ); }; $pm->finish; } If you want to run out of processes, take out the kill. I thought that setting a process group would work so I could kill everything together, but that blocks: my $alarm_sub = sub { kill 9, -$$; # blocks here die "Alarm rang for $$!\n"; }; foreach ( 0 .. $ARGV[1] ) { print "."; print "\n" unless $count++ % 50; my $pid = $pm->start and next; setpgrp(0, 0); local $SIG{ALRM} = $alarm_sub; eval { alarm( 2 ); system "$^X -le '<STDIN>'"; # this will hang alarm( 0 ); }; $pm->finish; } The same thing with POSIX's setsid didn't work either, and I think that actually broke things in a different way since I'm not really daemonizing this. Curiously, Parallel::ForkManager's run_on_finish happens too late for the same clean-up code: the grandchildren are apparently already disassociated from the child processes at that point.

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  • how do i search from php file ?

    - by Tum Bin
    Dear Friends, im totally new in php. Just learning. I got 2 Assingment with php and html. Assignment 01: I have to mansion some pplz name and all of them some friends name. and I have to print common friend if there have common friend. Bt there have a prob that I got also msg which dnt have any common friend like “Rana has 0 friends in common with Roni.” I want to stop this and how can i? Assignment 02: I made a html form to search a person from that php file. Like: when I will search for Rana php form will b open and and print : Rana have 4 friends and he has a common friend with Nandini and Mamun. when I will search for Tanmoy the page will be open and print: Tonmoy is Rana’s friend who have 4 friend and common friends with Nandini and Mamun. for this I have to use the function “post/get/request” Plz plz plzzzzzzzzzz help me! Here im posting my codes; <?php # Function: finfCommon function findCommon($current, $arr) { $cUser = $arr[$current]; unset($arr[$current]); foreach ($arr As $user => $friends) { $common = array(); $total = array(); foreach ($friends As $friend) { if (in_array($friend, $cUser)) { $common[] = $friend; } } $total = count($common); $add = ($total != 1) ? 's' : ''; $final[] = "<i>{$current} has {$total} friend{$add} in common with {$user}.</i>"; } return implode('<br />', $final); } # Array of users and friends $Friends = array( "Rana" => array("Pothik", "Zaman", "Tanmoy", "Ishita"), "Nandini" => array("Bonna", "Shakib", "Kamal", "Minhaj", "Ishita"), "Roni" => array("Akbar", "Anwar", "Khakan", "Pavel"), "Liton" => array("Mahadi", "Pavel"), "Mamun" => array("Meheli", "Tarek", "Zaman") ); # Creating the output value $output = "<ul>"; foreach ($Friends As $user => $friends) { $total = count($friends); $common = findCommon($user, $Friends); $output .= "<li><u>{$user} has {$total} friends.</u><br /><strong>Friends:</strong>"; if (is_array($friends) && !empty($friends[0])) { $output .= "<ul>"; foreach ($friends As $friend) { $output .= "<li>{$friend}</li>"; } $output .= "</ul>"; } $output .= "{$common}<br /><br /></li>"; } $output .= "</ul>"; # Printing the output value print $output; ?>

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  • tkinter frame does not show on startup

    - by Jzz
    this is my first question on SO, so correct me please if I make a fool of myself. I have this fairly complicated python / Tkinter application (python 2.7). On startup, the __init__ loads several frames, and loads a database. When that is finished, I want to set the application to a default state (there are 2 program states, 'calculate' and 'config'). Setting the state of the application means that the appropriate frame is displayed (using grid). When the program is running, the user can select a program state in the menu. Problem is, the frame is not displayed on startup. I get an empty application (menu bar and status bar are displayed). When I select a program state in the menu, the frame displays as it should. Question: What am I doing wrong? Should I update idletasks? I tried, but no result. Anything else? Background: I use the following to switch program states: def set_program_state(self, state): '''sets the program state''' #try cleaning all the frames: try: self.config_frame.grid_forget() except: pass try: self.tidal_calculations_frame.grid_forget() except: pass try: self.tidal_grapth_frame.grid_forget() except: pass if state == "calculate": print "Switching to calculation mode" self.tidal_calculations_frame.grid() #frame is preloaded self.tidal_calculations_frame.fill_data(routes=self.routing_data.routes, deviations=self.misc_data.deviations, ship_types=self.misc_data.ship_types) self.tidal_grapth_frame.grid() self.program_state = "calculate" elif state == "config": print "Switching to config mode" self.config_frame = GUI_helper.config_screen_frame(self, self.user) #load frame first (contents depend on type of user) self.config_frame.grid() self.program_state = "config" I understand that this is kind of messy to read, so I simplified things for testing, using this: def set_program_state(self, state): '''sets the program state''' #try cleaning all the frames: try: self.testlabel_1.grid_forget() except: pass try: self.testlabel_2.grid_forget() except: pass if state == "calculate": print "switching to test1" self.testlabel_1 = tk.Label(self, text="calculate", borderwidth=1, relief=tk.RAISED) self.testlabel_1.grid(row=0, sticky=tk.W+tk.E) elif state == "config": print "switching to test1" self.testlabel_2 = tk.Label(self, text="config", borderwidth=1, relief=tk.RAISED) self.testlabel_2.grid(row=0, sticky=tk.W+tk.E) But the result is the same. The frame (or label in this test) is not displayed at startup, but when the user selects the state (calling the same function) the frame is displayed. UPDATE the sample code in the comments (thanks for that!) pointed me in another direction. Further testing revealed (what I think) the cause of the problem. Disabling the display of the status bar made the program work as expected. Turns out, I used pack to display the statusbar and grid to display the frames. And they are in the same container, so problems arise. I fixed that by using only pack inside the main container. But the same problem is still there. This is what I use for the statusbar: self.status = GUI_helper.StatusBar(self.parent) self.status.pack(side=tk.BOTTOM, fill=tk.X) And if I comment out the last line (pack), the config frame loads on startup, as per this line: self.set_program_state("config") But if I let the status bar pack inside the main window, the config frame does not show. Where it does show when the user asks for it (with the same command as above).

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  • urllib2 misbehaving with dynamically loaded content

    - by Sheena
    Some Code headers = {} headers['user-agent'] = 'User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:16.0) Gecko/20100101 Firefox/16.0' headers['Accept'] = 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8' headers['Accept-Language'] = 'en-gb,en;q=0.5' #headers['Accept-Encoding'] = 'gzip, deflate' request = urllib.request.Request(sURL, headers = headers) try: response = urllib.request.urlopen(request) except error.HTTPError as e: print('The server couldn\'t fulfill the request.') print('Error code: {0}'.format(e.code)) except error.URLError as e: print('We failed to reach a server.') print('Reason: {0}'.format(e.reason)) else: f = open('output/{0}.html'.format(sFileName),'w') f.write(response.read().decode('utf-8')) A url http://groupon.cl/descuentos/santiago-centro The situation Here's what I did: enable javascript in browser open url above and keep an eye on the console disable javascript repeat step 2 use urllib2 to grab the webpage and save it to a file enable javascript open the file with browser and observe console repeat 7 with javascript off results In step 2 I saw that a whole lot of the page content was loaded dynamically using ajax. So the HTML that arrived was a sort of skeleton and ajax was used to fill in the gaps. This is fine and not at all surprising Since the page should be seo friendly it should work fine without js. in step 4 nothing happens in the console and the skeleton page loads pre-populated rendering the ajax unnecessary. This is also completely not confusing in step 7 the ajax calls are made but fail. this is also ok since the urls they are using are not local, the calls are thus broken. The page looks like the skeleton. This is also great and expected. in step 8: no ajax calls are made and the skeleton is just a skeleton. I would have thought that this should behave very much like in step 4 question What I want to do is use urllib2 to grab the html from step 4 but I cant figure out how. What am I missing and how could I pull this off? To paraphrase If I was writing a spider I would want to be able to grab plain ol' HTML (as in that which resulted in step 4). I dont want to execute ajax stuff or any javascript at all. I don't want to populate anything dynamically. I just want HTML. The seo friendly site wants me to get what I want because that's what seo is all about. How would one go about getting plain HTML content given the situation I outlined? To do it manually I would turn off js, navigate to the page and copy the html. I want to automate this. stuff I've tried I used wireshark to look at packet headers and the GETs sent off from my pc in steps 2 and 4 have the same headers. Reading about SEO stuff makes me think that this is pretty normal otherwise techniques such as hijax wouldn't be used. Here are the headers my browser sends: Host: groupon.cl User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:16.0) Gecko/20100101 Firefox/16.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Language: en-gb,en;q=0.5 Accept-Encoding: gzip, deflate Connection: keep-alive Here are the headers my script sends: Accept-Encoding: identity Host: groupon.cl Accept-Language: en-gb,en;q=0.5 Connection: close Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 User-Agent: User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:16.0) Gecko/20100101 Firefox/16.0 The differences are: my script has Connection = close instead of keep-alive. I can't see how this would cause a problem my script has Accept-encoding = identity. This might be the cause of the problem. I can't really see why the host would use this field to determine the user-agent though. If I change encoding to match the browser request headers then I have trouble decoding it. I'm working on this now... watch this space, I'll update the question as new info comes up

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  • Why is parsing a jSON response to a jQUERY ajax request not working

    - by Ankur
    I know there are several similar questions on SO, I have used some of them to get this far. I am trying to list a set of urls that match my input values. I have a servlet which takes some input e.g. "aus" in the example below and returns some output using out.print() e.g. the two urls I have shown below. EXAMPLE Input: "aus" Output: [{"url":"http://dbpedia.org/resource/Stifel_Nicolaus"},{"url":"http://sempedia.org/ontology/object/Australia"}] Which is exactly what I want. I have seen that firebug doesn't seem to have anything in the response section despite having called out.print(jsonString); and it seems that out.print(jsonString); is working as expected which suggests that the variable 'jsonString' contains the expected values. However I am not exactly sure what is wrong. -------- The jQuery --------- $(document).ready(function() { $("#input").keyup(function() { var input = $("#input").val(); //$("#output").html(input); ajaxCall(input); }); }); function ajaxCall(input) { // alert(input); $.ajax({ url: "InstantSearchServlet", data: "property="+input, beforeSend: function(x) { if(x && x.overrideMimeType) { x.overrideMimeType("application/j-son;charset=UTF-8"); } }, dataType: "json", success: function(data) { for (var i = 0, len = datalength; i < len; ++i) { var urlData = data[i]; $("#output").html(urlData.url); } } }); } ------ The Servlet that calls the DAO class - and returns the results ------- public class InstantSearchServlet extends HttpServlet{ private static final long serialVersionUID = 1L; public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { System.out.println("You called?"); response.setContentType("application/json"); PrintWriter out = response.getWriter(); InstantSearch is = new InstantSearch(); String input = (String)request.getParameter("property"); System.out.println(input); try { ArrayList<String> urllist; urllist = is.getUrls(input); String jsonString = convertToJSON(urllist); out.print(jsonString); System.out.println(jsonString); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } private String convertToJSON(ArrayList<String> urllist) { Iterator<String> itr = urllist.iterator(); JSONArray jArray = new JSONArray(); int i = 0; while (itr.hasNext()) { i++; JSONObject json = new JSONObject(); String url = itr.next(); try { json.put("url",url); } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); } jArray.put(json); } String results = jArray.toString(); return results; } }

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  • I'm looking for a reliable way to verify T-SQL stored procedures. Anybody got one?

    - by Cory Larson
    Hi all-- We're upgrading from SQL Server 2005 to 2008. Almost every database in the 2005 instance is set to 2000 compatibility mode, but we're jumping to 2008. Our testing is complete, but what we've learned is that we need to get faster at it. I've discovered some stored procedures that either SELECT data from missing tables or try to ORDER BY columns that don't exist. Wrapping the SQL to create the procedures in SET PARSEONLY ON and trapping errors in a try/catch only catches the invalid columns in the ORDER BYs. It does not find the error with the procedure selecting data from the missing table. SSMS 2008's intellisense, however, DOES find the issue, but I can still go ahead and successfully run the ALTER script for the procedure without it complaining. So, why can I even get away with creating a procedure that fails when it runs? Are there any tools out there that can do better than what I've tried? The first tool I found wasn't very useful: DbValidator from CodeProject, but it finds fewer problems than this script I found on SqlServerCentral, which found the invalid column references. ------------------------------------------------------------------------- -- Check Syntax of Database Objects -- Copyrighted work. Free to use as a tool to check your own code or in -- any software not sold. All other uses require written permission. ------------------------------------------------------------------------- -- Turn on ParseOnly so that we don't actually execute anything. SET PARSEONLY ON GO -- Create a table to iterate through declare @ObjectList table (ID_NUM int NOT NULL IDENTITY (1, 1), OBJ_NAME varchar(255), OBJ_TYPE char(2)) -- Get a list of most of the scriptable objects in the DB. insert into @ObjectList (OBJ_NAME, OBJ_TYPE) SELECT name, type FROM sysobjects WHERE type in ('P', 'FN', 'IF', 'TF', 'TR', 'V') order by type, name -- Var to hold the SQL that we will be syntax checking declare @SQLToCheckSyntaxFor varchar(max) -- Var to hold the name of the object we are currently checking declare @ObjectName varchar(255) -- Var to hold the type of the object we are currently checking declare @ObjectType char(2) -- Var to indicate our current location in iterating through the list of objects declare @IDNum int -- Var to indicate the max number of objects we need to iterate through declare @MaxIDNum int -- Set the inital value and max value select @IDNum = Min(ID_NUM), @MaxIDNum = Max(ID_NUM) from @ObjectList -- Begin iteration while @IDNum <= @MaxIDNum begin -- Load per iteration values here select @ObjectName = OBJ_NAME, @ObjectType = OBJ_TYPE from @ObjectList where ID_NUM = @IDNum -- Get the text of the db Object (ie create script for the sproc) SELECT @SQLToCheckSyntaxFor = OBJECT_DEFINITION(OBJECT_ID(@ObjectName, @ObjectType)) begin try -- Run the create script (remember that PARSEONLY has been turned on) EXECUTE(@SQLToCheckSyntaxFor) end try begin catch -- See if the object name is the same in the script and the catalog (kind of a special error) if (ERROR_PROCEDURE() <> @ObjectName) begin print 'Error in ' + @ObjectName print ' The Name in the script is ' + ERROR_PROCEDURE()+ '. (They don''t match)' end -- If the error is just that this already exists then we don't want to report that. else if (ERROR_MESSAGE() <> 'There is already an object named ''' + ERROR_PROCEDURE() + ''' in the database.') begin -- Report the error that we got. print 'Error in ' + ERROR_PROCEDURE() print ' ERROR TEXT: ' + ERROR_MESSAGE() end end catch -- Setup to iterate to the next item in the table select @IDNum = case when Min(ID_NUM) is NULL then @IDNum + 1 else Min(ID_NUM) end from @ObjectList where ID_NUM > @IDNum end -- Turn the ParseOnly back off. SET PARSEONLY OFF GO Any suggestions?

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  • Perl kill(0, $pid) in Windows always returning 1

    - by banshee_walk_sly
    I'm trying to make a Perl script that will run a set of other programs in Windows. I need to be able to capture the stdout, stderr, and exit code of the process, and I need to be able to see if a process exceeds it's allotted execution time. Right now, the pertinent part of my code looks like: ... $pid = open3($wtr, $stdout, $stderr, $command); if($time < 0){ waitpid($pid, 0); $return = $? >> 8; $death_sig = $? & 127; $core_dump = $? & 128; } else{ # Do timeout stuff, currently not working as planned print "pid: $pid\n"; my $elapsed = 0; #THIS LOOP ONLY TERMINATES WHEN $time > $elapsed ...? while(kill 0, $pid and $time > $elapsed){ Time::HiRes::usleep(1000); # sleep for milliseconds $elapsed += 1; $return = $? >> 8; $death_sig = $? & 127; $core_dump = $? & 128; } if($elapsed >= $time){ $status = "FAIL"; print $log "TIME LIMIT EXCEEDED\n"; } } #these lines are needed to grab the stdout and stderr in arrays so # I may reuse them in multiple logs if(fileno $stdout){ @stdout = <$stdout>; } if(fileno $stderr){ @stderr = <$stderr>; } ... Everything is working correctly if $time = -1 (no timeout is needed), but the system thinks that kill 0, $pid is always 1. This makes my loop run for the entirety of the time allowed. Some extra details just for clarity: This is being run on Windows. I know my process does terminate because I have get all the expected output. Perl version: This is perl, v5.10.1 built for MSWin32-x86-multi-thread (with 2 registered patches, see perl -V for more detail) Copyright 1987-2009, Larry Wall Binary build 1007 [291969] provided by ActiveState http://www.ActiveState.com Built Jan 26 2010 23:15:11 I appreciate your help :D For that future person who may have a similar issue I got the code to work, here is the modified code sections: $pid = open3($wtr, $stdout, $stderr, $command); close($wtr); if($time < 0){ waitpid($pid, 0); } else{ print "pid: $pid\n"; my $elapsed = 0; while(waitpid($pid, WNOHANG) <= 0 and $time > $elapsed){ Time::HiRes::usleep(1000); # sleep for milliseconds $elapsed += 1; } if($elapsed >= $time){ $status = "FAIL"; print $log "TIME LIMIT EXCEEDED\n"; } } $return = $? >> 8; $death_sig = $? & 127; $core_dump = $? & 128; if(fileno $stdout){ @stdout = <$stdout>; } if(fileno $stderr){ @stderr = <$stderr>; } close($stdout); close($stderr);

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  • reading a random access file

    - by user1067332
    The file I create has text in it, but when i try to read it, the output is null. here is the file the creates the text file, it creates the file and puts it in the right postion import java.util.*; import java.io.*; public class CreateCustomerFile { public static void main(String[] args) throws IOException { int pos; RandomAccessFile it = new RandomAccessFile("CustomerFile.txt", "rw"); Scanner input = new Scanner(System.in); int id; String name; int zip; final int RECORDSIZE = 100; final int NUMRECORDS = 1000; final int STOP = 99; try { for(int x = 0; x < NUMRECORDS; ++x) { it.writeInt(0); it.writeUTF(""); it.writeInt(0); } } catch(IOException e) { System.out.println("Error: " + e.getMessage()); } finally { it.close(); } it = new RandomAccessFile("CustomerFile.txt","rw"); try { System.out.print("Enter ID number" + " or " + STOP + " to quit "); id = input.nextInt(); while(id != STOP) { input.nextLine(); System.out.print("Enter last name"); name = input.nextLine(); System.out.print("Enter zipcode "); zip = input.nextInt(); pos = id - 1; it.seek(pos * RECORDSIZE); it.writeInt(id); it.writeUTF(name); it.writeInt(zip); System.out.print("Enter ID number" + " or " + STOP + " to quit "); id = input.nextInt(); } } catch(IOException e) { System.out.println("Error: " + e.getMessage()); } finally { it.close(); } } } Here is the file to read, the pos is correct but ouput always goes to the error: null. import javax.swing.*; import java.io.*; public class CustomerItemOrder { public static void main(String[] args) throws IOException { int pos; RandomAccessFile it = new RandomAccessFile("CustomerFile.txt","rw"); String inputString; int id, zip; String name; final int RECORDSIZE = 100; final int STOP = 99; inputString = JOptionPane.showInputDialog(null, "Enter id or "+ STOP + " to quit"); id = Integer.parseInt(inputString); try { while(id != STOP) { pos = id -1 ; it.seek(pos * RECORDSIZE ); id = it.readInt(); name = it.readLine(); zip = it.readInt(); JOptionPane.showMessageDialog(null, "ID:" + id + " last name is " + name + " and zipcode is " + zip); inputString = JOptionPane.showInputDialog(null, "Enter id or " + STOP + " to quit"); id = Integer.parseInt(inputString); } } catch(IOException e) { System.out.println("Error: " + e.getMessage()); } finally { it.close(); } } }

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  • How does java.util.Collections.contains() perform faster than a linear search?

    - by The111
    I've been fooling around with a bunch of different ways of searching collections, collections of collections, etc. Doing lots of stupid little tests to verify my understanding. Here is one which boggles me (source code further below). In short, I am generating N random integers and adding them to a list. The list is NOT sorted. I then use Collections.contains() to look for a value in the list. I intentionally look for a value that I know won't be there, because I want to ensure that the entire list space is probed. I time this search. I then do another linear search manually, iterating through each element of the list and checking if it matches my target. I also time this search. On average, the second search takes 33% longer than the first one. By my logic, the first search must also be linear, because the list is unsorted. The only possibility I could think of (which I immediately discard) is that Java is making a sorted copy of my list just for the search, but (1) I did not authorize that usage of memory space and (2) I would think that would result in MUCH more significant time savings with such a large N. So if both searches are linear, they should both take the same amount of time. Somehow the Collections class has optimized this search, but I can't figure out how. So... what am I missing? import java.util.*; public class ListSearch { public static void main(String[] args) { int N = 10000000; // number of ints to add to the list int high = 100; // upper limit for random int generation List<Integer> ints; int target = -1; // target will not be found, forces search of entire list space long start; long end; ints = new ArrayList<Integer>(); start = System.currentTimeMillis(); System.out.print("Generating new list... "); for (int i = 0; i < N; i++) { ints.add(((int) (Math.random() * high)) + 1); } end = System.currentTimeMillis(); System.out.println("took " + (end-start) + "ms."); start = System.currentTimeMillis(); System.out.print("Searching list for target (method 1)... "); if (ints.contains(target)) { // nothing } end = System.currentTimeMillis(); System.out.println(" Took " + (end-start) + "ms."); System.out.println(); ints = new ArrayList<Integer>(); start = System.currentTimeMillis(); System.out.print("Generating new list... "); for (int i = 0; i < N; i++) { ints.add(((int) (Math.random() * high)) + 1); } end = System.currentTimeMillis(); System.out.println("took " + (end-start) + "ms."); start = System.currentTimeMillis(); System.out.print("Searching list for target (method 2)... "); for (Integer i : ints) { // nothing } end = System.currentTimeMillis(); System.out.println(" Took " + (end-start) + "ms."); } }

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  • Why does this program stop running?

    - by designloper
    Hi everyone....I am developing a card making system...nothing fancy. Right got this far but program now stops running with no error when running after the first card sample i.e. " Enter 'OK' if this card is OK, otherwise enter an alternative border character: + ". Any suggestions Java Masters? //Ask user for input //makes use of print line method System.out.println("Enter name: "); //took the variables //called the object of the scanner 'cardOrder' //and use the Scanner objects method '.nextLine' //to read the next line of the input firstName = cardOrder.nextLine(); mInitial = cardOrder.nextLine(); lastName = cardOrder.nextLine(); //Print out the "Here is a sample card" + the first name, middle initial and last name System.out.println("Here is a sample card: \n\n" + firstName + mInitial + lastName + "**************" + "**************" + firstName + mInitial + lastName + "\n* *" + "\n*" + " " + firstName + mInitial + lastName + " *" + "\n* *\n" + firstName + mInitial + lastName +"**************" + "**************" + firstName + mInitial + lastName + "\n"); //Ask user is the card is OK to proceed to order query or if they want an alternative border character: + System.out.println("Enter 'OK' if this card is OK, otherwise enter an alternative border character: + "); //Check if user entered "OK" and store it in var optionA optionA = cardOrder.nextLine(); //test if (a == optionA){ System.out.println("\nHow many cards would you like? "); cardsOrdered = cardOrder.nextInt(); equals = (int) (cardPriceA * cardsOrdered); System.out.println("The price of " + cardsOrdered + " cards"+ " is £" + equals + ".\n"); System.out.println("No Discount given."); } else if(b == optionA) { //Print out the "Here is a sample card" + the first name, middle initial and last name System.out.println("Here is a sample card: \n\n" + firstName + mInitial + lastName + "++++++++++++++" + "++++++++++++++" + firstName + mInitial + lastName + "\n+ +" + "\n+" + " " + firstName + mInitial + lastName + " +" + "\n+ +\n" + firstName + mInitial + lastName +"++++++++++++++" + "++++++++++++++" + firstName + mInitial + lastName + "\n"); //Ask user is the card is OK to proceed to order query or if they want an alternative border character: + System.out.println("Enter 'OK' if this card is OK, otherwise enter an alternative border character: OK "); //Check if user entered "OK" and store it in var optionA optionA = cardOrder.nextLine(); if (a == optionA){ System.out.println("\nHow many cards would you like? "); cardsOrdered = cardOrder.nextInt(); equals = (int) (cardPriceA * cardsOrdered); System.out.println("The price of " + cardsOrdered + " cards"+ " is £" + equals + ".\n"); System.out.println("No Discount given."); } } else if (c == optionA) {//Print out the "Here is a sample card" + the first name, middle initial and last name System.out.println("Here is a sample card: \n\n" + firstName + mInitial + lastName + "**************" + "**************" + firstName + mInitial + lastName + "\n* *" + "\n*" + " " + firstName + mInitial + lastName + " *" + "\n* *\n" + firstName + mInitial + lastName +"**************" + "**************" + firstName + mInitial + lastName + "\n"); //Ask user is the card is OK to proceed to order query or if they want an alternative border character: + System.out.println("Enter 'OK' if this card is OK, otherwise enter an alternative border character: + "); //Check if user entered "OK" and store it in var optionA optionA = cardOrder.nextLine(); if (a == optionA){ System.out.println("\nHow many cards would you like? "); cardsOrdered = cardOrder.nextInt(); equals = (int) (cardPriceA * cardsOrdered); System.out.println("The price of " + cardsOrdered + " cards"+ " is £" + equals + ".\n"); System.out.println("No Discount given."); } }

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  • Custom language - FOR loop in a clojure interpeter?

    - by Mark
    I have a basic interpreter in clojure. Now i need to implement for (initialisation; finish-test; loop-update) { statements } Implement a similar for-loop for the interpreted language. The pattern will be: (for variable-declarations end-test loop-update do statement) The variable-declarations will set up initial values for variables.The end-test returns a boolean, and the loop will end if end-test returns false. The statement is interpreted followed by the loop-update for each pass of the loop. Examples of use are: (run ’(for ((i 0)) (< i 10) (set i (+ 1 i)) do (println i))) (run ’(for ((i 0) (j 0)) (< i 10) (seq (set i (+ 1 i)) (set j (+ j (* 2 i)))) do (println j))) inside my interpreter. I will attach my interpreter code I got so far. Any help is appreciated. Interpreter (declare interpret make-env) ;; needed as language terms call out to 'interpret' (def do-trace false) ;; change to 'true' to show calls to 'interpret' ;; simple utilities (def third ; return third item in a list (fn [a-list] (second (rest a-list)))) (def fourth ; return fourth item in a list (fn [a-list] (third (rest a-list)))) (def run ; make it easy to test the interpreter (fn [e] (println "Processing: " e) (println "=> " (interpret e (make-env))))) ;; for the environment (def make-env (fn [] '())) (def add-var (fn [env var val] (cons (list var val) env))) (def lookup-var (fn [env var] (cond (empty? env) 'error (= (first (first env)) var) (second (first env)) :else (lookup-var (rest env) var)))) ;; for terms in language ;; -- define numbers (def is-number? (fn [expn] (number? expn))) (def interpret-number (fn [expn env] expn)) ;; -- define symbols (def is-symbol? (fn [expn] (symbol? expn))) (def interpret-symbol (fn [expn env] (lookup-var env expn))) ;; -- define boolean (def is-boolean? (fn [expn] (or (= expn 'true) (= expn 'false)))) (def interpret-boolean (fn [expn env] expn)) ;; -- define functions (def is-function? (fn [expn] (and (list? expn) (= 3 (count expn)) (= 'lambda (first expn))))) (def interpret-function ; keep function definitions as they are written (fn [expn env] expn)) ;; -- define addition (def is-plus? (fn [expn] (and (list? expn) (= 3 (count expn)) (= '+ (first expn))))) (def interpret-plus (fn [expn env] (+ (interpret (second expn) env) (interpret (third expn) env)))) ;; -- define subtraction (def is-minus? (fn [expn] (and (list? expn) (= 3 (count expn)) (= '- (first expn))))) (def interpret-minus (fn [expn env] (- (interpret (second expn) env) (interpret (third expn) env)))) ;; -- define multiplication (def is-times? (fn [expn] (and (list? expn) (= 3 (count expn)) (= '* (first expn))))) (def interpret-times (fn [expn env] (* (interpret (second expn) env) (interpret (third expn) env)))) ;; -- define division (def is-divides? (fn [expn] (and (list? expn) (= 3 (count expn)) (= '/ (first expn))))) (def interpret-divides (fn [expn env] (/ (interpret (second expn) env) (interpret (third expn) env)))) ;; -- define equals test (def is-equals? (fn [expn] (and (list? expn) (= 3 (count expn)) (= '= (first expn))))) (def interpret-equals (fn [expn env] (= (interpret (second expn) env) (interpret (third expn) env)))) ;; -- define greater-than test (def is-greater-than? (fn [expn] (and (list? expn) (= 3 (count expn)) (= '> (first expn))))) (def interpret-greater-than (fn [expn env] (> (interpret (second expn) env) (interpret (third expn) env)))) ;; -- define not (def is-not? (fn [expn] (and (list? expn) (= 2 (count expn)) (= 'not (first expn))))) (def interpret-not (fn [expn env] (not (interpret (second expn) env)))) ;; -- define or (def is-or? (fn [expn] (and (list? expn) (= 3 (count expn)) (= 'or (first expn))))) (def interpret-or (fn [expn env] (or (interpret (second expn) env) (interpret (third expn) env)))) ;; -- define and (def is-and? (fn [expn] (and (list? expn) (= 3 (count expn)) (= 'and (first expn))))) (def interpret-and (fn [expn env] (and (interpret (second expn) env) (interpret (third expn) env)))) ;; -- define print (def is-print? (fn [expn] (and (list? expn) (= 2 (count expn)) (= 'println (first expn))))) (def interpret-print (fn [expn env] (println (interpret (second expn) env)))) ;; -- define with (def is-with? (fn [expn] (and (list? expn) (= 3 (count expn)) (= 'with (first expn))))) (def interpret-with (fn [expn env] (interpret (third expn) (add-var env (first (second expn)) (interpret (second (second expn)) env))))) ;; -- define if (def is-if? (fn [expn] (and (list? expn) (= 4 (count expn)) (= 'if (first expn))))) (def interpret-if (fn [expn env] (cond (interpret (second expn) env) (interpret (third expn) env) :else (interpret (fourth expn) env)))) ;; -- define function-application (def is-function-application? (fn [expn env] (and (list? expn) (= 2 (count expn)) (is-function? (interpret (first expn) env))))) (def interpret-function-application (fn [expn env] (let [function (interpret (first expn) env)] (interpret (third function) (add-var env (first (second function)) (interpret (second expn) env)))))) ;; the interpreter itself (def interpret (fn [expn env] (cond do-trace (println "Interpret is processing: " expn)) (cond ; basic values (is-number? expn) (interpret-number expn env) (is-symbol? expn) (interpret-symbol expn env) (is-boolean? expn) (interpret-boolean expn env) (is-function? expn) (interpret-function expn env) ; built-in functions (is-plus? expn) (interpret-plus expn env) (is-minus? expn) (interpret-minus expn env) (is-times? expn) (interpret-times expn env) (is-divides? expn) (interpret-divides expn env) (is-equals? expn) (interpret-equals expn env) (is-greater-than? expn) (interpret-greater-than expn env) (is-not? expn) (interpret-not expn env) (is-or? expn) (interpret-or expn env) (is-and? expn) (interpret-and expn env) (is-print? expn) (interpret-print expn env) ; special syntax (is-with? expn) (interpret-with expn env) (is-if? expn) (interpret-if expn env) ; functions (is-function-application? expn env) (interpret-function-application expn env) :else 'error))) ;; tests of using environment (println "Environment tests:") (println (add-var (make-env) 'x 1)) (println (add-var (add-var (add-var (make-env) 'x 1) 'y 2) 'x 3)) (println (lookup-var '() 'x)) (println (lookup-var '((x 1)) 'x)) (println (lookup-var '((x 1) (y 2)) 'x)) (println (lookup-var '((x 1) (y 2)) 'y)) (println (lookup-var '((x 3) (y 2) (x 1)) 'x)) ;; examples of using interpreter (println "Interpreter examples:") (run '1) (run '2) (run '(+ 1 2)) (run '(/ (* (+ 4 5) (- 2 4)) 2)) (run '(with (x 1) x)) (run '(with (x 1) (with (y 2) (+ x y)))) (run '(with (x (+ 2 4)) x)) (run 'false) (run '(not false)) (run '(with (x true) (with (y false) (or x y)))) (run '(or (= 3 4) (> 4 3))) (run '(with (x 1) (if (= x 1) 2 3))) (run '(with (x 2) (if (= x 1) 2 3))) (run '((lambda (n) (* 2 n)) 4)) (run '(with (double (lambda (n) (* 2 n))) (double 4))) (run '(with (sum-to (lambda (n) (if (= n 0) 0 (+ n (sum-to (- n 1)))))) (sum-to 100))) (run '(with (x 1) (with (f (lambda (n) (+ n x))) (with (x 2) (println (f 3))))))

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