Search Results

Search found 22427 results on 898 pages for 'opn program'.

Page 808/898 | < Previous Page | 804 805 806 807 808 809 810 811 812 813 814 815  | Next Page >

• Writing own Unix shell in C - Problems with PATH and execv

  - by user1287523

  I'm writing my own shell in C. It needs to be able to display the users current directory, execute commands based on the full path (must use execv), and allow the user to change the directory with cd. This IS homework. The teacher only gave us a basic primer on C and a very brief skeleton on how the program should work. Since I'm not one to give up easily I've been researching how to do this for three days, but now I'm stumped. This is what I have so far: Displays the user's username, computername, and current directory (defaults to home directory). Prompts the user for input, and gets the input Splits the user's input by " " into an array of arguments Splits the environment variable PATH by ":" into an array of tokens I'm not sure how to proceed from here. I know I've got to use the execv command but in my research on google I haven't really found an example I understand. For instance, if the command is bin/ls, how does execv know the display all files/folders from the home directory? How do I tell the system I changed the directory? I've been using this site a lot which has been helpful: http://linuxgazette.net/111/ramankutty.html but again, I'm stumped. Thanks for your help. Let me know if I should post some of my existing code, I'm wasn't sure if it was necessary though.

  Read the article

• Best (functional?) programming language to learn coming from Mathematica

  - by Will Robertson

  As a mechanical engineering PhD student, I haven't had a great pedigree in programming as part of my “day job”. I started out in Matlab (having written some Hypercard and Applescript back in the day, and being introduced to Ada, of all things, in my 1st undergrad year), learned to program—if you can call it that—in (La)TeX; and finally discovered and fell for Mathematica. Now I'm interested in learning a "real" programming language that I can enjoy in the same sort of style as Mathematica, which tries to stress functional programming since it seems to map more nicely to how certain kinds of mathematics can be written algorithmically. So which functional language should I learn? I guess the obvious answer is “as many as possible”, but let's start out humble and give a single, well-considered option a good crack. I've heard good things about, say, Haskell and Scala, but I wonder if (given my non–computer science background) I'd be better off starting in more “grounded” territory and going with Ruby or Python (the latter having the big advantage of being used for Sage, which I'd also like to investigate…after my PhD). Well, I guess this is pretty subjective, so perhaps I could rephrase: would it be better to start looking at Haskell (say) straight after an ad-hoc education to functional programming in Mathematica, or will I get more out of learning Python (say) first? In reference to the question "what do I want to do with it?", I guess my answer is "fun, and learning more". I've got this list of languages that I'd like to look at, and I don't know how to trim them down. And I'd rather start with something a little higher-level than C simply so that I can be somewhat productive without having to re-invent many wheels for any code I'd like to write.

  Read the article

• Design for fastest page download

  - by mexxican

  I have a file with millions of URLs/IPs and have to write a program to download the pages really fast. The connection rate should be at least 6000/s and file download speed at least 2000 with avg. 15kb file size. The network bandwidth is 1 Gbps. My approach so far has been: Creating 600 socket threads with each having 60 sockets and using WSAEventSelect to wait for data to read. As soon as a file download is complete, add that memory address(of the downloaded file) to a pipeline( a simple vector ) and fire another request. When the total download is more than 50Mb among all socket threads, write all the files downloaded to the disk and free the memory. So far, this approach has been not very successful with the rate at which I could hit not shooting beyond 2900 connections/s and downloaded data rate even less. Can somebody suggest an alternative approach which could give me better stats. Also I am working windows server 2008 machine with 8 Gig of memory. Also, do we need to hack the kernel so as we could use more threads and memory. Currently I can create a max. of 1500 threads and memory usage not going beyond 2 gigs [ which technically should be much more as this is a 64-bit machine ]. And IOCP is out of question as I have no experience in that so far and have to fix this application today. Thanks Guys!

  Read the article

• Which is faster: Appropriate data input or appropriate data structure?

  - by Anon

  I have a dataset whose columns look like this: Consumer ID | Product ID | Time Period | Product Score 1 | 1 | 1 | 2 2 | 1 | 2 | 3 and so on. As part of a program (written in C) I need to process the product scores given by all consumers for a particular product and time period combination for all possible combinations. Suppose that there are 3 products and 2 time periods. Then I need to process the product scores for all possible combinations as shown below: Product ID | Time Period 1 | 1 1 | 2 2 | 1 2 | 2 3 | 1 3 | 2 I will need to process the data along the above lines lots of times ( 10k) and the dataset is fairly large (e.g., 48k consumers, 100 products, 24 time periods etc). So speed is an issue. I came up with two ways to process the data and am wondering which is the faster approach or perhaps it does not matter much? (speed matters but not at the cost of undue maintenance/readability): Sort the data on product id and time period and then loop through the data to extract data for all possible combinations. Store the consumer ids of all consumers who provided product scores for a particular combination of product id and time period and process the data accordingly. Any thoughts? Any other way to speed up the processing? Thanks

  Read the article

• Is there a way to receive data as unsigned char over UDP on Qt?

  - by user269037

  I need to send floating point numbers using a UDP connection to a Qt application. Now in Qt the only function available is qint64 readDatagram ( char * data, qint64 maxSize, QHostAddress * address = 0, quint16 * port = 0 ) which accepts data in the form of signed character buffer. I can convert my float into a string and send it but it will obviously not be very efficient converting a 4 byte float into a much longer sized character buffer. I got hold of these 2 functions to convert a 4 byte float into an unsinged 32 bit integer to transfer over network which works fine for a simple C++ UDP program but for Qt I need to receive the data as unsigned char. Is it possible to avoid converting the floatinf point data into a string and then sending it? uint32_t htonf(float f) { uint32_t p; uint32_t sign; if (f < 0) { sign = 1; f = -f; } else { sign = 0; } p = ((((uint32_t)f)&0x7fff)<<16) | (sign<<31); // Whole part and sign. p |= (uint32_t)(((f - (int)f) * 65536.0f))&0xffff; // Fraction. return p; } float ntohf(uint32_t p) { float f = ((p>>16)&0x7fff); // Whole part. f += (p&0xffff) / 65536.0f; // Fraction. if (((p>>31)&0x1) == 0x1) { f = -f; } // Sign bit set. return f; }

  Read the article

• Python 2.6 does not like appending to existing archives in zip files

  - by user313661

  Hello, In some Python unit tests of a program I'm working on we use in-memory zipfiles for end to end tests. In SetUp() we create a simple zip file, but in some tests we want to overwrite some archives. For this we do "zip.writestr(archive_name, zip.read(archive_name) + new_content)". Something like import zipfile from StringIO import StringIO def Foo(): zfile = StringIO() zip = zipfile.ZipFile(zfile, 'a') zip.writestr( "foo", "foo content") zip.writestr( "bar", "bar content") zip.writestr( "foo", zip.read("foo") + "some more foo content") print zip.read("bar") Foo() The problem is that this works fine in Python 2.4 and 2.5, but not 2.6. In Python 2.6 this fails on the print line with "BadZipfile: File name in directory "bar" and header "foo" differ." It seems that it is reading the correct file bar, but that it thinks it should be reading foo instead. I'm at a loss. What am I doing wrong? Is this not supported? I tried searching the web but could find no mention of similar problems. I read the zipfile documentation, but could not find anything (that I thought was) relevant, especially since I'm calling read() with the filename string. Any ideas? Thank you in advance!

  Read the article

• iOS TableView crash don't know how. Here is the app

  - by jollyr0ger

  Hi! In my app that you can download here: http://ge.tt/2DDqfJa I've started a discussion but is died here iOS TableView crash loading different data The problem is when I back from viewing the YouTube video to the recipes list, the app crash... And when i select a category for the second time, where have to load a tableview with different data source, it crash. This is the crash log Program received signal: “EXC_BAD_ACCESS”. (gdb) bt #0 0x00f0da63 in objc_msgSend () #1 0x04b27ca0 in ?? () #2 0x00002665 in -[RecipesListController viewWillAppear:] (self=0x4b38a00, _cmd=0x6d81a2, animated=1 '\001') at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/RecipesListController.m:67 #3 0x00370c9a in -[UINavigationController _startTransition:fromViewController:toViewController:] () #4 0x0036b606 in -[UINavigationController _startDeferredTransitionIfNeeded] () #5 0x0037283e in -[UINavigationController pushViewController:transition:forceImmediate:] () #6 0x04f49549 in -[UINavigationControllerAccessibility(SafeCategory) pushViewController:transition:forceImmediate:] () #7 0x0036b4a0 in -[UINavigationController pushViewController:animated:] () #8 0x00003919 in -[CategoryViewController tableView:didSelectRowAtIndexPath:] (self=0x4b27ca0, _cmd=0x6d19e3, tableView=0x500c200, indexPath=0x4b2d650) at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/CategoryViewCotroller.m:104 #9 0x0032a794 in -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:] () #10 0x00320d50 in -[UITableView _userSelectRowAtPendingSelectionIndexPath:] () #11 0x000337f6 in __NSFireDelayedPerform () #12 0x00d8cfe3 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ () #13 0x00d8e594 in __CFRunLoopDoTimer () #14 0x00ceacc9 in __CFRunLoopRun () #15 0x00cea240 in CFRunLoopRunSpecific () #16 0x00cea161 in CFRunLoopRunInMode () #17 0x016e0268 in GSEventRunModal () #18 0x016e032d in GSEventRun () #19 0x002c342e in UIApplicationMain () #20 0x00001c08 in main (argc=1, argv=0xbfffef58) at /Users/claudiocanino/Documents/iOS/CottoMangiato/main.m:15 Another bt log: (gdb) bt #0 0x00cd76a1 in __CFBasicHashDeallocate () #1 0x00cc2bcb in _CFRelease () #2 0x00002dd6 in -[RecipesListController setRecipesArray:] (self=0x6834d50, _cmd=0x4293, _value=0x4e3bc70) at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/RecipesListController.m:16 #3 0x00002665 in -[RecipesListController viewWillAppear:] (self=0x6834d50, _cmd=0x6d81a2, animated=1 '\001') at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/RecipesListController.m:67 #4 0x00370c9a in -[UINavigationController _startTransition:fromViewController:toViewController:] () #5 0x0036b606 in -[UINavigationController _startDeferredTransitionIfNeeded] () #6 0x0037283e in -[UINavigationController pushViewController:transition:forceImmediate:] () #7 0x091ac549 in -[UINavigationControllerAccessibility(SafeCategory) pushViewController:transition:forceImmediate:] () #8 0x0036b4a0 in -[UINavigationController pushViewController:animated:] () #9 0x00003919 in -[CategoryViewController tableView:didSelectRowAtIndexPath:] (self=0x4b12970, _cmd=0x6d19e3, tableView=0x5014400, indexPath=0x4b2bd00) at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/CategoryViewCotroller.m:104 #10 0x0032a794 in -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:] () #11 0x00320d50 in -[UITableView _userSelectRowAtPendingSelectionIndexPath:] () #12 0x000337f6 in __NSFireDelayedPerform () #13 0x00d8cfe3 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ () #14 0x00d8e594 in __CFRunLoopDoTimer () #15 0x00ceacc9 in __CFRunLoopRun () #16 0x00cea240 in CFRunLoopRunSpecific () #17 0x00cea161 in CFRunLoopRunInMode () #18 0x016e0268 in GSEventRunModal () #19 0x016e032d in GSEventRun () #20 0x002c342e in UIApplicationMain () #21 0x00001c08 in main (argc=1, argv=0xbfffef58) at /Users/claudiocanino/Documents/iOS/CottoMangiato/main.m:15 Thanks

  Read the article

• Using functions and arrays

  - by Ordo

  Hello! My little program below shall take 5 numbers from the user, store them into an array of integers and use a function to print them out. Sincerly it doesn't work and my output is always "00000". I can't find a mistake, so i would be glad about any advice. Thanks. #include <stdio.h> void printarray(int intarray[], int n) { int i; for(i = 0; i < n; i ++) { printf("%d", intarray[i]); } } int main () { const int n = 5; int temp = 0; int i; int intarray [n]; char check; printf("Please type in your numbers!\n"); for(i = 0; i < n; i ++) { printf(""); scanf("&d", &temp); intarray[i] = temp; getchar(); getchar(); } printf("Do you want to print them out? (yes/no): "); scanf("%c", &check); if (check == 'y') printarray(intarray, n); getchar(); getchar(); return 0; }

  Read the article

• Launching and Intent from file and mime type

  - by stonedonkey

  I've reviewed all the similar questions here, but I can't for the life of me figure out what I'm doing wrong. I've written an application that tries to launch various files, sort of a file browser, when a file is clicked it tries to launch the program based on it's associated MIME type or I want it to present the "Choose Application to Launch" dialog. Here's the code I'm using to launch: File file = new File(app.mediaPath() + "/" +_mediaFiles.get(position)); Intent myIntent = new Intent(android.content.Intent.ACTION_VIEW); String extension = android.webkit.MimeTypeMap.getFileExtensionFromUrl(Uri.fromFile(file).toString()); String mimetype = android.webkit.MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension); myIntent.setDataAndType(Uri.fromFile(file),mimetype); startActivity(myIntent); This fails and generates a: android.content.ActivityNotFoundException: No Activity found to handle Intent { act=android.intent.action.VIEW dat=file:///file:/mnt/sdcard/roms/nes/Baseball_simulator.nes } Now if I install OI File Manager for instance, it opens instead of this error being thrown, and then if I click the same file from within in it, it launches the approriate dialogs. I have noticed that the MIME type for that particular file fails, but other mime types like .zip do return values. Am I missing something that when the MIME type is null to call a dialog that lets the user select? I've tried other variations of launching the app, including not setting the mime type and only using .setData with no success. The action I want to happen is, a user clicks a file, if it's associated with an application that app launches, if not, the user gets the "Complete action using" dialog with a list of apps. Thanks for any advice.

  Read the article

• C++ reference variable again!!!

  - by kumar_m_kiran

  Hi All, I think most would be surprised about the topic again, However I am referring to a book "C++ Common Knowledge: Essential Intermediate Programming" written by "Stephen C. Dewhurst". In the book, he quotes a particular sentence (in section under Item 5. References Are Aliases, Not Pointers), which is as below A reference is an alias for an object that already exists prior to the initialization of the reference. Once a reference is initialized to refer to a particular object, it cannot later be made to refer to a different object; a reference is bound to its initializer for its whole lifetime Can anyone please explain the context of "cannot later be made to refer to a different object" Below code works for me, #include <iostream> using namespace std; int main(int argc, char *argv[]) { int i = 100; int& ref = i; cout<<ref<<endl; int k = 2000; ref = k; cout<<ref<<endl; return 0; } Here I am referring the variable ref to both i and j variable. And the code works perfectly fine. Am I missing something? I have used SUSE10 64bit linux for testing my sample program. Thanks for your input in advance.

  Read the article

• How can I use io.StringIO() with the csv module?

  - by Tim Pietzcker

  I tried to backport a Python 3 program to 2.7, and I'm stuck with a strange problem: >>> import io >>> import csv >>> output = io.StringIO() >>> output.write("Hello!") # Fail: io.StringIO expects Unicode Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: unicode argument expected, got 'str' >>> output.write(u"Hello!") # This works as expected. 6L >>> writer = csv.writer(output) # Now let's try this with the csv module: >>> csvdata = [u"Hello", u"Goodbye"] # Look ma, all Unicode! (?) >>> writer.writerow(csvdata) # Sadly, no. Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: unicode argument expected, got 'str' According to the docs, io.StringIO() returns an in-memory stream for Unicode text. It works correctly when I try and feed it a Unicode string manually. Why does it fail in conjunction with the csv module, even if all the strings being written are Unicode strings? Where does the str come from that causes the Exception? (I do know that I can use StringIO.StringIO() instead, but I'm wondering what's wrong with io.StringIO() in this scenario)

  Read the article

• JQuery transition animation

  - by kk-dev11

  This program randomly selects two employees from a json-object Employees array, winnerPos is already defined. For better user experience I programmed these functions to change pictures one by one. The animation stops when the randomly selected person is shown on the screen. The slideThrough function will be triggered when the start button is pressed. function slideThrough() { counter = 0; start = true; clearInterval(picInterval); picInterval = setInterval(function () { changePicture(); }, 500); } function changePicture() { if (start) { if (counter > winnerPos) { setWinner(); start = false; killInterval(); } else { var employee = Employees[counter]; winnerPic.fadeOut(200, function () { this.src = 'img/' + employee.image; winnerName.html(employee.name); $(this).fadeIn(300); }); counter++; } } } The problem is the animation doesn't work smoothly. At first it works, but not perfect. The second time the transition happens in an irregular way, i.e. different speed and fadeIn/fadeOut differs from picture to picture. Could anyone help me to fine-tune the transition?

  Read the article

• Compile Apache 2.4.3 on Centos 6.2 (64bit)

  - by RiseCakoPlusplus

  I attempt to compile Apache 2.4.3 with apr-1.4.6 and apr-util-1.5.1 on Centos 6.2 (64bit). ./configure --build=x86_64-unknown-linux-gnu --host=x86_64-unknown-linux-gnu --target=x86_64-redhat-linux-gnu --program-prefix= --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64 --libexecdir=/usr/libexec --localstatedir=/var --sharedstatedir=/var/lib --mandir=/usr/share/man --infodir=/usr/share/info --cache-file=../config.cache --with-libdir=lib64 --with-config-file-path=/etc --with-config-file-scan-dir=/etc/php.d --disable-debug --with-pic --disable-rpath --without-pear --with-bz2 --with-exec-dir=/usr/bin --with-freetype-dir=/usr --with-png-dir=/usr --with-xpm-dir=/usr --enable-gd-native-ttf --with-t1lib=/usr --without-gdbm --with-gettext --with-gmp --with-iconv --with-jpeg-dir=/usr --with-openssl --with-zlib --with-layout=GNU --enable-exif --enable-ftp --enable-magic-quotes --enable-sockets --with-kerberos --enable-ucd-snmp-hack --enable-shmop --enable-calendar --with-libxml-dir=/usr --enable-xml --with-system-tzdata --with-mhash --with-apxs2=/usr/sbin/apxs --libdir=/usr/lib64/php --enable-pdo=shared --with-mysql=shared,/usr --with-mysqli=shared,/usr/lib64/mysql/mysql_config --with-pdo-mysql=shared,/usr/lib64/mysql/mysql_config --without-pdo-sqlite --without-gd --disable-dom --disable-dba --without-unixODBC --disable-xmlreader --disable-xmlwriter --without-sqlite3 --disable-phar --disable-fileinfo --disable-json --without-pspell --disable-wddx --without-curl --disable-posix --disable-sysvmsg --disable-sysvshm --disable-sysvsem ./configure --with-included-apr --with-included-apr-util and when I issue make this happen: /root/httpd-2.4.3/srclib/apr/libtool: line 5989: cd: yes/lib: No such file or directory libtool: link: cannot determine absolute directory name of yes/lib' make[3]: *** [libaprutil-1.la] Error 1 make[3]: Leaving directory/root/httpd-2.4.3/srclib/apr-util' make[2]: * [all-recursive] Error 1 make[2]: Leaving directory /root/httpd-2.4.3/srclib/apr-util' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory/root/httpd-2.4.3/srclib' make: * [all-recursive] Error 1 anything I missed?

  Read the article

• Unable to Connect to Management Studio Server

  - by Phil Hilliard

  I have a nasty situation. I am using Microsoft SQL Server Management Studio Express edition locally on my pc for testing, and once tested I upload database changes to a remote server. I have a situation where I deleted the Default Database on my local machine, and instead of searching hard enough to find an answer to that problem, I uninstalled and reinstalled Management Studio. Since then Management Studio has not been able to connect to the server. Is there any help (or hope for me for that matter), out there????? The following is the detailed error message: =================================== Cannot connect to LENOVO-E7A54767\SQLEXPRESS. =================================== A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) (.Net SqlClient Data Provider) ------------------------------ For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&EvtSrc=MSSQLServer&EvtID=-1&LinkId=20476 ------------------------------ Error Number: -1 Severity: 20 State: 0 ------------------------------ Program Location: at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) at System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, SqlConnection owningObject) at System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject) at System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart) at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.SqlClient.SqlConnection.Open() at Microsoft.SqlServer.Management.UI.VSIntegration.ObjectExplorer.ObjectExplorer.ValidateConnection(UIConnectionInfo ci, IServerType server) at Microsoft.SqlServer.Management.UI.ConnectionDlg.Connector.ConnectionThreadUser()

  Read the article

• zend_db and join

  - by premtemp

  Hello, I am trying to understand how to use Zend_DB in my program but I have some problem. The class below (DatabaseService) work when I pass it a simple query. However, if I pass it it query with a join clause my page just hangs and not error is return. I cut and paste the qry in a query browesr and it is valid Any help would be great $SQL = "select name from mytable" $db = new DatabaseService($dbinfo) $db ->fetchall($SQL ) // works ----------------------------------------------------------- $SQL = "select count(*) as cnt from EndPoints join CallID on EndPoints.`CallID` = CallID.CallID where EndPoints.LastRegister >= '2010-04-21 00:00:01' and EndPoints.LastRegister <= '2010-04-21 23:59:59' " $db = new DatabaseService($dbinfo) $db ->fetchall($SQL ) // DOES NO WORK class DatabaseService { function DatabaseService($dbinfo,$dbname="") { try { $dbConfig = array( 'host' => $this->host, 'username' => $this->username, 'password' => $password, 'dbname' => $this->dbname ); $this->db = Zend_Db::factory($this->adapter, $dbConfig); Zend_Db_Table::setDefaultAdapter($this->db); } catch(Zend_Exception $e) { $this->error = $e->getMessage(); Helper::log($this->error); return false; } } public function connnect() { if($this->db !=null) { try { $this->db->getConnection(); return true; } catch (Zend_Exception $e) { $err = "FAILED ::".$e->getMessage()." <br />"; } } return false; } public function fetchall($sql) { $res= $this->db->fetchAll($sql); return $res; } }

  Read the article

• how can i make sure to get the server response correctly when i invoke the server with QNetworkReque

  - by noname

  I wrote the server site call in Qt, but i haven't get the server response for every server invoking. I have to use the server reply to continue the program flow. The request is correctly reached to server and server do reply.The server is also on my machine. Here is the code how i make the server site call; QNetworkAccessManager nam1 = new QNetworkAccessManager(this); qnetmg=nam1; QObject::connect(nam1, SIGNAL(finished(QNetworkReply*)),this,SLOT(finishedGettingMarker(QNetworkReply*))); QString strurl="http://localhost:8080/ServerWeb"; QUrl url(strurl); QNetworkRequest preq(url); QNetworkReply* reply = nam1->get(preq); qreply=reply; Inside finisedGettingMarker slot, i have already eliminate for QNetworkReply-error case and i used one global variable for QNetworkAccessManager;"qnetmg" and one global variable for QNetworkReply;"qreply". And also i make qnetmg.disconnect(this,0); and qreply.abort(); inside that slot method. But the problem is i haven't got the response for every server invoking time. If anyone who know the way to solve it , please reply me. This situation happened only in Opera. Thanks in advance.

  Read the article

• C vs C++ function questions

  - by james

  I am learning C, and after starting out learning C++ as my first compiled language, I decided to "go back to basics" and learn C. There are two questions that I have concerning the ways each language deals with functions. Firstly, why does C "not care" about the scope that functions are defined in, whereas C++ does? For example, int main() { donothing(); return 0; } void donothing() { } the above will not compile in a C++ compiler, whereas it will compile in a C compiler. Why is this? Isn't C++ mostly just an extension on C, and should be mostly "backward compatible"? Secondly, the book that I found (Link to pdf) does not seem to state a return type for the main function. I check around and found other books and websites and these also commonly do not specify return types for the main function. If I try to compile a program that does not specify a return type for main, it compiles fine (although with some warnings) in a C compiler, but it doesn't compile in a C++ compiler. Again, why is that? Is it better style to always specify the return type as an integer rather than leaving it out? Thanks for any help, and just as a side note, if anyone can suggest a better book that I should buy that would be great!

  Read the article

• TCP/IP Implementation General Questions

  - by user2971023

  I've implemented the concepts shown here; http://wiki.unity3d.com/index.php/Simple_TCP/IP_Client_-_Server outside of unity and it works. (though i had to create the TCPIPServerApp from scratch as i could not find the base project anywhere). I have some general questions on how to use tcp/ip properly however. I've done some research on tcp/ip itself but I'm still a little confused. It seems like using the method above doesn't guarantee that I'll see the message (res). It just checks on every update to see if there is a different message in res. What if multiple messages are sent and the program lags or something, will i miss the earlier packet(s)? Should i instead do an array so it stores the last X messages? How do i know the data was received? Do I need to add a message id and build in my own ack into the data? Should i check to see if the port is in use before setting up a connection? Sorry for all the questions. This is all new to me but I enjoy this very much! ... Below already answered By Anton, Thanks It sounds like tcp uses its own packet numbering to ensure the packets end up in the right order on the other side. What if a packet is missed, are the subsequent packets thrown away? Or is this numbering and packet ordering, only for handling data that is broken out into multiple packets? TCP will automatically break the data into multiple packets if necessary right?

  Read the article

• C++: Simple data type for a variable in IF statement?

  - by Jason

  I am new to C++ and am making a simple text RPG, anyway, The scenario is I have a "welcome" screen with choices 1-3, and have a simple IF statement to check them, here: int choice; std::cout << "--> "; std::cin >> choice; if(choice == 1) { //.. That works fine, but if someone enters a letter as selection (instead of 1, 2 or 3) it'll become "-392493492"or something and crash the program. So I came up with: char choice; std::cout << "--> "; std::cin >> choice; if(choice == 1) { //.. This works kinda fine, but when I enter a number it seems to skip the IF statements completely.. Is the char "1" the same as the number 1? I get a compiler errro with this (ISO-CPP or something): if(choice == "1") So how on earth do I see if they entered 1-3 correctly!?

  Read the article

• SEO Problem for new dictionary site, google hasn't indexed content.

  - by John

  I loaded about 15,000 pages, letters A & B of a dictionary and submitted to google a text site map. I'm using google's search with advertisement as the planned mechanism to go through my site. Google's webmaster accepted the site mapps as good but then did not index. My index page has been indexed by google and at this point have not linked to any pages. So to get google's search to work I need to get all my content indexed. It appears google will not just index from the site map and so I was thinking of adding pages that spider in links from the main index page. But I don't want to create a bunch of pages that programicly link all of the pages without knowing if this has a chance to work. Eventually I plan on having about 150,000 pages each page being a word or phrase being defined. I wrote a program that is pulling this from a dictionary database. I would like to prove the content that I have to anyone interested to show the value of the dictionary in releation to the dictionary software that I'm completing. Suggestions for getting the entire site indexed by google so I can appear in the search results? Thanks

  Read the article

• Why does reusing arrays increase performance so significantly in c#?

  - by Willem

  In my code, I perform a large number of tasks, each requiring a large array of memory to temporarily store data. I have about 500 tasks. At the beginning of each task, I allocate memory for an array : double[] tempDoubleArray = new double[M]; M is a large number depending on the precise task, typically around 2000000. Now, I do some complex calculations to fill the array, and in the end I use the array to determine the result of this task. After that, the tempDoubleArray goes out of scope. Profiling reveals that the calls to construct the arrays are time consuming. So, I decide to try and reuse the array, by making it static and reusing it. It requires some additional juggling to figure out the minimum size of the array, requiring an extra pass through all tasks, but it works. Now, the program is much faster (from 80 sec to 22 sec for execution of all tasks). double[] tempDoubleArray = staticDoubleArray; However, I'm a bit in the dark of why precisely this works so well. Id say that in the original code, when the tempDoubleArray goes out of scope, it can be collected, so allocating a new array should not be that hard right? I ask this because understanding why it works might help me figuring out other ways to achieve the same effect, and because I would like to know in what cases allocation gives performance issues.

  Read the article

• Type-safe generic data structures in plain-old C?

  - by Bradford Larsen

  I have done far more C++ programming than "plain old C" programming. One thing I sorely miss when programming in plain C is type-safe generic data structures, which are provided in C++ via templates. For sake of concreteness, consider a generic singly linked list. In C++, it is a simple matter to define your own template class, and then instantiate it for the types you need. In C, I can think of a few ways of implementing a generic singly linked list: Write the linked list type(s) and supporting procedures once, using void pointers to go around the type system. Write preprocessor macros taking the necessary type names, etc, to generate a type-specific version of the data structure and supporting procedures. Use a more sophisticated, stand-alone tool to generate the code for the types you need. I don't like option 1, as it is subverts the type system, and would likely have worse performance than a specialized type-specific implementation. Using a uniform representation of the data structure for all types, and casting to/from void pointers, so far as I can see, necessitates an indirection that would be avoided by an implementation specialized for the element type. Option 2 doesn't require any extra tools, but it feels somewhat clunky, and could give bad compiler errors when used improperly. Option 3 could give better compiler error messages than option 2, as the specialized data structure code would reside in expanded form that could be opened in an editor and inspected by the programmer (as opposed to code generated by preprocessor macros). However, this option is the most heavyweight, a sort of "poor-man's templates". I have used this approach before, using a simple sed script to specialize a "templated" version of some C code. I would like to program my future "low-level" projects in C rather than C++, but have been frightened by the thought of rewriting common data structures for each specific type. What experience do people have with this issue? Are there good libraries of generic data structures and algorithms in C that do not go with Option 1 (i.e. casting to and from void pointers, which sacrifices type safety and adds a level of indirection)?

  Read the article

• What is better for a student programming in C++ to learn for writing GUI: C# vs QT?

  - by flashnik

  I'm a teacher(instructor) of CS in the university. The course is based on Cormen and Knuth and students program algorithms in C++. But sometimes it is good to show how an algorithm works or just a result of task through GUI. Also in my opinion it's very imporant to be able to write full programs. They will have courses concerning GUI but a three years, later, in fact, before graduatuion. I think that they should be able to write simple GUI applications earlier. So I want to teach them it. How do you think, what is more useful for them to learn: programming GUI with QT or writing GUI in C# and calling unmanaged C++ library? Update. For developing C++ applications students use MS Visual studio, so C# is already installed. But QT AFAIK also can be integrated into VS. I have following pros of C# (some were suggested there in answers): The need to make an additional layer. It's more work, but it forces you explicitly specify contract between GUI and processing data. The border between GUI and algorithms becomes very clear. It's more popular among employers. At least, in Russia where we live. It's rather common to write performance-critical algorithms in C++ and PInvoke them from well-looking C# application/ASP.Net website. Maybe it is not so widespread in the rest of the world but in Russia Windows is very popular, especially in companies and corporations due to some reasons, so most of b2b applications are Windows applications. Rapid development. It's much quicker to code in .Net then in C++ due to many reasons. And the con is that it's a new language with own specific for students. And the mess with invoking calls to library.

  Read the article

• .net remoting - Better solution to wait for a service to initialize ?

  - by CitizenInsane

  Context I have a client application (which i cannot modify, i.e. i only have the binary) that needs to run from time to time external commands that depends on a resource which is very long to initialize (about 20s). I thus decided to initialize this resource once for all in a "CommandServer.exe" application (single instance in the system tray) and let my client application call an intermediate "ExecuteCommand.exe" program that uses .net remoting to perform the operation on the server. The "ExecuteCommand.exe" is in charge for starting the server on first call and then leave it alive to speed up further commands. The service: public interface IMyService { void ExecuteCommand(string[] args); } The "CommandServer.exe" (using WindowsFormsApplicationBase for single instance management + user friendly splash screen during resource initializations): private void onStartupFirstInstance(object sender, StartupEventArgs e) { // Register communication channel channel = new TcpServerChannel("CommandServerChannel", 8234); ChannelServices.RegisterChannel(channel, false); // Register service var resource = veryLongToInitialize(); service = new MyServiceImpl(resource); RemotingServices.Marshal(service, "CommandServer"); // Create icon in system tray notifyIcon = new NotifyIcon(); ... } The intermediate "ExecuteCommand.exe": static void Main(string[] args) { startCommandServerIfRequired(); var channel = new TcpClientChannel(); ChannelServices.RegisterChannel(channel, false); var service = (IMyService)Activator.GetObject(typeof(IMyService), "tcp://localhost:8234/CommandServer"); service.RunCommand(args); } Problem As the server is very long to start (about 20s to initialize the required resources), the "ExecuteCommand.exe" fails on service.RunCommand(args) line because the server is yet not available. Question Is there a elegant way I can tune the delay before to receive "service not available" when calling service.RunCommand ? NB1: Currently I'm working around the issue by adding a mutex in server to indicate for complete initiliazation and have "ExecuteCommand.exe" to wait for this mutex before to call service.RunCommand. NB2: I have no background with .net remoting, nor WCF which is recommended replacer. (I chose .net remoting because this looked easier to set-up for this single shot issue in running external commands).

  Read the article

• Aliasing `T*` with `char*` is allowed. Is it also allowed the other way around?

  - by StackedCrooked

  Note: This question has been renamed and reduced to make it more focused and readable. Most of the comments refer to the old text. According to the standard objects of different type may not share the same memory location. So this would not be legal: int i = 0; short * s = reinterpret_cast<short*>(&i); // BAD! The standard however allows an exception to this rule: any object may be accessed through a pointer to char or unsigned char: int i = 0; char * c = reinterpret_cast<char*>(&i); // OK However, it is not clear to me if this is also allowed the other way around. For example: char * c = read_socket(...); unsigned * u = reinterpret_cast<unsigned*>(c); // huh? Summary of the answers The answer is NO for two reasons: You an only access an existing object as char*. There is no object in my sample code, only a byte buffer. The pointer address may not have the right alignment for the target object. In that case dereferencing it would result in undefined behavior. On the Intel and AMD platforms it will result performance overhead. On ARM it will trigger a CPU trap and your program will be terminated! This is a simplified explanation. For more detailed information see answers by @Luc Danton, @Cheers and hth. - Alf and @David Rodríguez.

  Read the article

< Previous Page | 804 805 806 807 808 809 810 811 812 813 814 815  | Next Page >