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  • Why does File::Slurp return a scalar when it should return a list?

    - by BrianH
    I am new to the File::Slurp module, and on my first test with it, it was not giving the results I was expecting. It took me a while to figure it out, so now I am interested in why I was seeing this certain behavior. My call to File::Slurp looked like this: my @array = read_file( $file ) || die "Cannot read $file\n"; I included the "die" part because I am used to doing that when opening files. My @array would always end up with the entire contents of the file in the first element of the array. Finally I took out the "|| die" section, and it started working as I expected. Here is an example to illustrate: perl -de0 Loading DB routines from perl5db.pl version 1.22 Editor support available. Enter h or `h h' for help, or `man perldebug' for more help. main::(-e:1): 0 DB<1> use File::Slurp DB<2> $file = '/usr/java6_64/copyright' DB<3> x @array1 = read_file( $file ) 0 'Licensed material - Property of IBM.' 1 'IBM(R) SDK, Java(TM) Technology Edition, Version 6' 2 'IBM(R) Runtime Environment, Java(TM) Technology Edition, Version 6' 3 '' 4 'Copyright Sun Microsystems Inc, 1992, 2008. All rights reserved.' 5 'Copyright IBM Corporation, 1998, 2009. All rights reserved.' 6 '' 7 'The Apache Software License, Version 1.1 and Version 2.0' 8 'Copyright 1999-2007 The Apache Software Foundation. All rights reserved.' 9 '' 10 'Other copyright acknowledgements can be found in the Notices file.' 11 '' 12 'The Java technology is owned and exclusively licensed by Sun Microsystems Inc.' 13 'Java and all Java-based trademarks and logos are trademarks or registered' 14 'trademarks of Sun Microsystems Inc. in the United States and other countries.' 15 '' 16 'US Govt Users Restricted Rights - Use duplication or disclosure' 17 'restricted by GSA ADP Schedule Contract with IBM Corp.' DB<4> x @array2 = read_file( $file ) || die "Cannot read $file\n"; 0 'Licensed material - Property of IBM. IBM(R) SDK, Java(TM) Technology Edition, Version 6 IBM(R) Runtime Environment, Java(TM) Technology Edition, Version 6 Copyright Sun Microsystems Inc, 1992, 2008. All rights reserved. Copyright IBM Corporation, 1998, 2009. All rights reserved. The Apache Software License, Version 1.1 and Version 2.0 Copyright 1999-2007 The Apache Software Foundation. All rights reserved. Other copyright acknowledgements can be found in the Notices file. The Java technology is owned and exclusively licensed by Sun Microsystems Inc. Java and all Java-based trademarks and logos are trademarks or registered trademarks of Sun Microsystems Inc. in the United States and other countries. US Govt Users Restricted Rights - Use duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. ' Why does the || die make a difference? I have a feeling this might be more of a Perl precedence question instead of a File::Slurp question. I looked in the File::Slurp module and it looks like it is set to croak if there is a problem, so I guess the proper way to do it is to allow File::Slurp to croak for you. Now I'm just curious why I was seeing these differences.

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  • Java File Handling, what did I do wrong?

    - by Urda
    Wrote up a basic file handler for a Java Homework assignment, and when I got the assignment back I had some notes about failing to catch a few instances: Buffer from file could have been null. File was not found File stream wasn't closed Here is the block of code that is used for opening a file: /** * Create a Filestream, Buffer, and a String to store the Buffer. */ FileInputStream fin = null; BufferedReader buffRead = null; String loadedString = null; /** Try to open the file from user input */ try { fin = new FileInputStream(programPath + fileToParse); buffRead = new BufferedReader(new InputStreamReader(fin)); loadedString = buffRead.readLine(); fin.close(); } /** Catch the error if we can't open the file */ catch(IOException e) { System.err.println("CRITICAL: Unable to open text file!"); System.err.println("Exiting!"); System.exit(-1); } The one comment I had from him was that fin.close(); needed to be in a finally block, which I did not have at all. But I thought that the way I have created the try/catch it would have prevented an issue with the file not opening. Let me be clear on a few things: This is not for a current assignment (not trying to get someone to do my own work), I have already created my project and have been graded on it. I did not fully understand my Professor's reasoning myself. Finally, I do not have a lot of Java experience, so I was a little confused why my catch wasn't good enough.

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  • Char error C langauge

    - by Nadeem tabbaa
    i have a project for a course, i did almost everything but i have this error i dont know who to solve it... the project about doing our own shell some of them we have to write our code, others we will use the fork method.. this is the code, #include <sys/wait.h> #include <dirent.h> #include <limits.h> #include <errno.h> #include <stdlib.h> #include <string.h> #include<stdio.h> #include<fcntl.h> #include<unistd.h> #include<sys/stat.h> #include<sys/types.h> int main(int argc, char **argv) { pid_t pid; char str[21], *arg[10]; int x,status,number; system("clear"); while(1) { printf("Rshell>" ); fgets(str,21,stdin); x = 0; arg[x] = strtok(str, " \n\t"); while(arg[x]) arg[++x] = strtok(NULL, " \n\t"); if(NULL!=arg[0]) { if(strcasecmp(arg[0],"cat")==0) //done { int f=0,n; char l[1]; struct stat s; if(x!=2) { printf("Mismatch argument\n"); } /*if(access(arg[1],F_OK)) { printf("File Exist"); exit(1); } if(stat(arg[1],&s)<0) { printf("Stat ERROR"); exit(1); } if(S_ISREG(s.st_mode)<0) { printf("Not a Regular FILE"); exit(1); } if(geteuid()==s.st_uid) if(s.st_mode & S_IRUSR) f=1; else if(getegid()==s.st_gid) if(s.st_mode & S_IRGRP) f=1; else if(s.st_mode & S_IROTH) f=1; if(!f) { printf("Permission denied"); exit(1); }*/ f=open(arg[1],O_RDONLY); while((n=read(f,l,1))>0) write(1,l,n); } else if(strcasecmp(arg[0],"rm")==0) //done { if( unlink( arg[1] ) != 0 ) perror( "Error deleting file" ); else puts( "File successfully deleted" ); } else if(strcasecmp(arg[0],"rmdir")==0) //done { if( remove( arg[1] ) != 0 ) perror( "Error deleting Directory" ); else puts( "Directory successfully deleted" ); } else if(strcasecmp(arg[0],"ls")==0) //done { DIR *dir; struct dirent *dirent; char *where = NULL; //printf("x== %i\n",x); //printf("x== %s\n",arg[1]); //printf("x== %i\n",get_current_dir_name()); if (x == 1) where = get_current_dir_name(); else where = arg[1]; if (NULL == (dir = opendir(where))) { fprintf(stderr,"%d (%s) opendir %s failed\n", errno, strerror(errno), where); return 2; } while (NULL != (dirent = readdir(dir))) { printf("%s\n", dirent->d_name); } closedir(dir); } else if(strcasecmp(arg[0],"cp")==0) //not yet for Raed { FILE *from, *to; char ch; if(argc!=3) { printf("Usage: copy <source> <destination>\n"); exit(1); } /* open source file */ if((from = fopen(argv[1], "rb"))==NULL) { printf("Cannot open source file.\n"); exit(1); } /* open destination file */ if((to = fopen(argv[2], "wb"))==NULL) { printf("Cannot open destination file.\n"); exit(1); } /* copy the file */ while(!feof(from)) { ch = fgetc(from); if(ferror(from)) { printf("Error reading source file.\n"); exit(1); } if(!feof(from)) fputc(ch, to); if(ferror(to)) { printf("Error writing destination file.\n"); exit(1); } } if(fclose(from)==EOF) { printf("Error closing source file.\n"); exit(1); } if(fclose(to)==EOF) { printf("Error closing destination file.\n"); exit(1); } } else if(strcasecmp(arg[0],"mv")==0)//done { if( rename(arg[1],arg[2]) != 0 ) perror( "Error moving file" ); else puts( "File successfully moved" ); } else if(strcasecmp(arg[0],"hi")==0)//done { printf("hello\n"); } else if(strcasecmp(arg[0],"exit")==0) // done { return 0; } else if(strcasecmp(arg[0],"sleep")==0) // done { if(x==1) printf("plz enter the # seconds to sleep\n"); else sleep(atoi(arg[1])); } else if(strcmp(arg[0],"history")==0) // not done { FILE *infile; //char fname[40]; char line[100]; int lcount; ///* Read in the filename */ //printf("Enter the name of a ascii file: "); //fgets(History.txt, sizeof(fname), stdin); /* Open the file. If NULL is returned there was an error */ if((infile = fopen("History.txt", "r")) == NULL) { printf("Error Opening File.\n"); exit(1); } while( fgets(line, sizeof(line), infile) != NULL ) { /* Get each line from the infile */ lcount++; /* print the line number and data */ printf("Line %d: %s", lcount, line); } fclose(infile); /* Close the file */ writeHistory(arg); //write to txt file every new executed command //read from the file once the history command been called //if a command called not for the first time then just replace it to the end of the file } else if(strncmp(arg[0],"@",1)==0) // not done { //scripting files // read from the file command by command and executing them } else if(strcmp(arg[0],"type")==0) //not done { //if(x==1) //printf("plz enter the argument\n"); //else //type((arg[1])); } else { pid = fork( ); if (pid == 0) { execlp(arg[0], arg[0], arg[1], arg[2], NULL); printf ("EXEC Failed\n"); } else { wait(&status); if(strcmp(arg[0],"clear")!=0) { printf("status %04X\n",status); if(WIFEXITED(status)) printf("Normal termination, exit code %d\n", WEXITSTATUS(status)); else printf("Abnormal termination\n"); } } } } } } void writeHistory(char *arg[]) { FILE *file; file = fopen("History.txt","a+"); /* apend file (add text to a file or create a file if it does not exist.*/ int i =0; while(strcasecmp(arg[0],NULL)==0) { fprintf(file,"%s ",arg[i]); /*writes*/ } fprintf(file,"\n"); /*new line*/ fclose(file); /*done!*/ getchar(); /* pause and wait for key */ //return 0; } the thing is when i compile the code, this what it gives me /home/ugics/st255375/ICS431Labs/Project/Rshell.c: At top level: /home/ugics/st255375/ICS431Labs/Project/Rshell.c:264: warning: conflicting types for ‘writeHistory’ /home/ugics/st255375/ICS431Labs/Project/Rshell.c:217: note: previous implicit declaration of ‘writeHistory’ was here can any one help me??? thanks

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  • Handling the Outlook 2007 AutoArchive PST file

    - by Doug Luxem
    We encourage our users to enable AutoArchive in Outlook 2007 as a way to manage their mailbox sizes. However, we frequently end up running in to problems with the archive.pst file that is generated. The two main problems we have are: The archive.pst file is located in the user's local profile directory and is never backed up. A dead hard drive or stolen laptop could result in months or years of missing email. All other personal data is stored on network shares, but we can't do that for Outlook PST files. Without some sort of manual intervention, the archive will grow to enormous sizes. Although Outlook 2007 SP2 handles the large files better than before, it still results in slow response times from Outlook and an increase likelihood of a corrupt PST file. To mitigate these problems personally, I move the archives to a c:\Outlook folder and manually back that up to a shared drive every month or so. Additionally, I rotate archive files every year so that I have one file for each year (archive2008.pst, etc). Obviously, asking our users to do this same wouldn't help much. We need some sort of automated solution to take care of points 1 and 2. I have to imagine this is a common problem for Exchange organizations, so what is the best method to handle this?

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  • Is it possible to have a global exception hook?

    - by Heinrich Ulbricht
    Hi, my code is fairly well covered with exception handling (try..except). Some exceptions are not expected to happen and some exceptions happen fairly often, which is expected and ok. Now I want to add some automated tests for this code. It would be good to know how many exceptions happened during execution, so I can later see if the expected number was raised or anything unexpected happened. I don't want to clutter every exception handling block with debug code, so my question is: Is there a way to install some kind of global exception handler which sits right before all other exception handling blocks? I am searching for a central place to log these exceptions. Thanks for any suggestions! (And if this matters: it is Delphi 2009)

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  • File path for J2ME FileConnection?

    - by Kilnr
    Hi, I'm writing a MIDlet which needs to write file. I'm using FileConnection from JSR-75 to accomplish this. The intention is to have this MIDlet runnning on as much devices as possible (all MIDP 2.0 devices with JSR-75 support, ideally). On several emulators and an HTC Touch Pro2, I can perfectly use the following code to get the root of the filesystem: Enumeration drives = FileSystemRegistry.listRoots(); String root = (String) drives.nextElement(); String path = "file:///" + root; However, on a Nokia S60 5th edition emulator, trying to open a FileConnection to this path throws a java.lang.SecurityException. Apparently S60 devices do not allow connections to the root of the filesystem. I realise I can use something like System.getProperty("fileconn.dir.photos"), but that isn't supported on all devices either. So, my actual question: what is the best approach to get a path to create a FileConnection with, that allows for maximum portability? Thanks. Edit: I suppose I could iterate over all the roots in the Enumeration, and check for a writable one, but that's hardly optimal for two reasons. First, there aren't necessarily any writable roots. Second, this could be the phone memory or a memory card, so the storage method wouldn't be consistent across devices, which is rather ugly.

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  • Iterating arrays in a batch file

    - by dboarman-FissureStudios
    I am writing a batch file (I asked a question on SU) to iterate over terminal servers searching for a specific user. So, I got the basic start of what I'm trying to do. Enter a user name Iterate terminal servers Display servers where user is found (they can be found on multiple servers now and again depending on how the connection is lost) Display a menu of options Iterating terminal servers I have: for /f "tokens=1" %%Q in ('query termserver') do (set __TermServers.%%Q) Now, I am getting the error... Environment variable __TermServers.SERVER1 not defined ...for each of the terminal servers. This is really the only thing in my batch file at this point. Any idea on why this error is occurring? Obviously, the variable is not defined, but I understood the SET command to do just that. I'm also thinking that in order to continue working on the iteration (each terminal server), I will need to do something like: :Search for /f "tokens=1" %%Q in ('query termserver') do (call Process) goto Break :Process for /f "tokens=1" %%U in ('query user %%username%% /server:%%Q') do (set __UserConnection = %%C) goto Search However, there are 2 things that bug me about this: Is the %%Q value still alive when calling Process? When I goto Search, will the for-loop be starting over? I'm doing this with the tools I have at my disposal, so as much as I'd like to hear about PowerShell and other ways to do this, it would be futile. I have notepad and that's it. Note: I would continue this line of questions on SuperUser, except that it seems to be getting more into programming specifics.

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  • File extensions and MIME Types in .NET

    - by Marc Climent
    I want to get a MIME Content-Type from a given extension (preferably without accessing the physical file). I have seen some questions about this and the methods described to perform this can be resumed in: Use registry information. Use urlmon.dll's FindMimeFromData. Use IIS information. Roll your own MIME mapping function. Based on this table, for example. I've been using no.1 for some time but I realized that the information provided by the registry is not consistent and depends on the software installed on the machine. Some extensions, like .zip don't use to have a Content-Type specified. Solution no.2 forces me to have the file on disk in order to read the first bytes, which is something slow but may get good results. The third method is based on Directory Services and all that stuff, which is something I don't like much because I have to add COM references and I'm not sure it's consistent between IIS6 and IIS7. Also, I don't know the performance of this method. Finally, I didn't want to use my own table but at the end seems the best option if I want a decent performance and consistency of the results between platforms (even Mono). Do you think there's a better option than using my own table or one of other described methods are better? What's your experience?

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  • File Format DOS/Unix/MAC code sample

    - by mac
    I have written the following method to detemine whether file in question is formatted with DOS/ MAC, or UNIX line endings. I see at least 1 obvious issue: 1. i am hoping that i will get the EOL on the first run, say within first 1000 bytes. This may or may not happen. I ask you to review this and suggest improvements which will lead to hardening the code and making it more generic. THANK YOU. new FileFormat().discover(fileName, 0, 1000); and then public void discover(String fileName, int offset, int depth) throws IOException { BufferedInputStream in = new BufferedInputStream(new FileInputStream(fileName)); FileReader a = new FileReader(new File(fileName)); byte[] bytes = new byte[(int) depth]; in.read(bytes, offset, depth); a.close(); in.close(); int thisByte; int nextByte; boolean isDos = false; boolean isUnix = false; boolean isMac = false; for (int i = 0; i < (bytes.length - 1); i++) { thisByte = bytes[i]; nextByte = bytes[i + 1]; if (thisByte == 10 && nextByte != 13) { isDos = true; break; } else if (thisByte == 13) { isUnix = true; break; } else if (thisByte == 10) { isMac = true; break; } } if (!(isDos || isMac || isUnix)) { discover(fileName, offset + depth, depth + 1000); } else { // do something clever } }

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  • Websphere logs report {0} File not found, but application continues to work without issues

    - by Eric
    A websphere 6.1 server is running a struts application that seems to be working fine. In the logs, however, I'm seeing the following error message, which is being continually emailed to the support staff. com.ibm.ws.webcontainer.webapp.WebAppErrorReport: SRVE0190E: File not found: {0} at com.ibm.ws.webcontainer.webapp.WebAppDispatcherContext.sendError(WebAppDispatcherContext.java:536) at com.ibm.ws.webcontainer.srt.SRTServletResponse.sendError(SRTServletResponse.java:930) at com.ibm.ws.webcontainer.extension.DefaultExtensionProcessor.handleRequest(DefaultExtensionProcessor.java:524) at com.ibm.ws.wswebcontainer.extension.DefaultExtensionProcessor.handleRequest(DefaultExtensionProcessor.java:111) at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:3129) at com.ibm.ws.webcontainer.webapp.WebGroup.handleRequest(WebGroup.java:238) at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:811) at com.ibm.ws.wswebcontainer.WebContainer.handleRequest(WebContainer.java:1433) at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:93) I can narrow down the issue to a single Action and JSP, which are too big to show here, but here's the action definition in struts-config.xml: <action path="/HappyDefaultThing" name="HappyDefaultThingActionForm" type="com.foo.webadministration.action.HappyDefaultThingAction" validate="true" input="/WaAssignDefaultHappyThing.jsp" scope="session"> <forward name="success" path="/WaAssignDefaultHappyThing.jsp"/> <forward name="failure" path="/WaAssignDefaultHappyThing.jsp"/> </action> As far as I can see, nothing is missing, and everything necessary is being found, but the logs say "File not found: {0}" What is "{0}"?? The stack trace only shows IBMs code, which I can't see the source of, and therefore can't trace. Is this a bug in the websphere code? I'd appreciate any help.

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  • Using fgets to read strings from file in C

    - by Ivan
    I am trying to read strings from a file that has each string on a new line but I think it reads a newline character once instead of a string and I don't know why. If I'm going about reading strings the wrong way please correct me. i=0; F1 = fopen("alg.txt", "r"); F2 = fopen("tul.txt", "w"); if(!feof(F1)) { do{ //start scanning file fgets(inimene[i].Enimi, 20, F1); fgets(inimene[i].Pnimi, 20, F1); fgets(inimene[i].Kood, 12, F1); printf("i=%d\nEnimi=%s\nPnimi=%s\nKaad=%s",i,inimene[i].Enimi,inimene[i].Pnimi,inimene[i].Kood); i++;} while(!feof(F1));}; /*finish getting structs*/ The printf is there to let me see what was read into what and here is the result i=0 Enimi=peter Pnimi=pupkin Kood=223456iatb i=1 Enimi= Pnimi=masha Kaad=gubkina i=2 Enimi=234567iasb Pnimi=sasha Kood=dudkina As you can see after the first struct is read there is a blank(a newline?) onct and then everything is shifted. I suppose I could read a dummy string to absorb that extra blank and then nothing would be shifted, but that doesn't help me understand the problem and avoid in the future.

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  • Append data to file in iPhone app

    - by zp26
    I have a problem. I want to create a file like XML. I have create a code for this but the file not append the information but rewrite and save only the last NSData. Can you help me/ This is my code -(void)salvataggioInXML:(NSString*)name:(float)x:(float)y:(float)z{ NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectoryPath = [paths objectAtIndex:0]; NSString *filePath = [documentsDirectoryPath stringByAppendingPathComponent:@"filePosizioni.xml"]; NSFileHandle *myHandle = [NSFileHandle fileHandleForUpdatingAtPath:filePath]; [myHandle seekToEndOfFile]; NSString *tagName = [NSString stringWithFormat:@"<name>%@<name>", name]; NSString *tagX = [NSString stringWithFormat:@"<x>%f<x>", name]; NSString *tagY = [NSString stringWithFormat:@"<y>%f<y>", name]; NSString *tagZ = [NSString stringWithFormat:@"<z>%f<z>", name]; NSData* dataName = [tagName dataUsingEncoding: NSASCIIStringEncoding]; NSData* dataX = [tagX dataUsingEncoding: NSASCIIStringEncoding]; NSData* dataY = [tagY dataUsingEncoding: NSASCIIStringEncoding]; NSData* dataZ = [tagZ dataUsingEncoding: NSASCIIStringEncoding]; if ([dataName writeToFile:filePath atomically:YES]) NSLog(@"writeok"); [myHandle seekToEndOfFile]; if ([dataX writeToFile:filePath atomically:YES]) NSLog(@"writeok"); [myHandle seekToEndOfFile]; if ([dataY writeToFile:filePath atomically:YES]) NSLog(@"writeok"); [myHandle seekToEndOfFile]; if ([dataZ writeToFile:filePath atomically:YES]) NSLog(@"writeok"); [myHandle seekToEndOfFile]; NSLog(@"zp26 %@",filePath); }

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  • How to load an HTML file into an included PHP file from another PHP?

    - by Peter NGM
    i have 2 PHP file and 1 HTML. i want to include file2.php in file1.php. file1.php is: <html> <head>...</head> <body> ... <?php include("file2.php"); ?> ... </body> </html> i want to load an HTML file in file2.php: file2.php is: <?php $doc = new DOMDocument(); $doc->loadHTMLFile("sample.html"); echo $doc->saveHTML(); ?> and sample.html is: ... <b>Hello World!</b> ... my problem is this error: Warning: DOMDocument::loadHTMLFile() [domdocument.loadhtmlfile]: I/O warning : failed to load external entity "sample.html" in C:\xampp\htdocs\project\file2.php on line 3 please help me to solve this problem.

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  • max file upload size change in web.config

    - by Christopher Johnson
    using .net mvc 3 and trying to increase the allowable file upload size. This is what I've added to web.config: <system.webServer> <validation validateIntegratedModeConfiguration="false"/> <modules runAllManagedModulesForAllRequests="true"> <add name="ErrorLog" type="Elmah.ErrorLogModule, Elmah" preCondition="managedHandler" /> <add name="ErrorMail" type="Elmah.ErrorMailModule, Elmah" preCondition="managedHandler" /> <add name="ErrorFilter" type="Elmah.ErrorFilterModule, Elmah" preCondition="managedHandler" /> </modules> <handlers> <add name="Elmah" path="elmah.axd" verb="POST,GET,HEAD" type="Elmah.ErrorLogPageFactory, Elmah" preCondition="integratedMode" /> </handlers> <security> <requestFiltering> <requestLimits maxAllowedContentLength="104857600"/> </requestFiltering> </security> *ignore the elmah stuff. it's still not allowing file sizes larger than 50MB and this should allow up to 100MB no? any ideas?

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  • find and replace values in a flat-file using PHP

    - by peirix
    I'd think there was a question on this already, but I can't find one. Maybe the solution is too easy... Anyway, I have a flat-file and want to let the user change the values based on a name. I've already sorted out creating new name+value-pairs using the fopen('a') mode, using jQuery to send the AJAX call with newValue and newName. But say the content looks like this: host|http:www.stackoverflow.com folder|/questions/ folder2|/users/ And now I want to change the folder value. So I'll send in folder as oldName and /tags/ as newValue. What's the best way to overwrite the value? The order in the list doesn't matter, and the name will always be on the left, followed by a |(pipe), the value and then a new-line. My first thought was to read the list, store it in an array, search all the [0]'s for oldName, then change the [1] that belongs to it, and then write it back to a file. But I feel there is a better way around this? Any ideas? Maybe regex?

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  • Atomic int writes on file

    - by Waneck
    Hello! I'm writing an application that will have to be able to handle many concurrent accesses to it, either by threads as by processes. So no mutex'es or locks should be applied to this. To make the use of locks go down to a minimum, I'm designing for the file to be "append-only", so all data is first appended to disk, and then the address pointing to the info it has updated, is changed to refer to the new one. So I will need to implement a small lock system only to change this one int so it refers to the new address. How is the best way to do it? I was thinking about maybe putting a flag before the address, that when it's set, the readers will use a spin lock until it's released. But I'm afraid that it isn't at all atomic, is it? e.g. a reader reads the flag, and it is unset on the same time, a writer writes the flag and changes the value of the int the reader may read an inconsistent value! I'm looking for locking techniques but all I find is either for thread locking techniques, or to lock an entire file, not fields. Is it not possible to do this? How do append-only databases handle this? Thanks! Cauê

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  • MalformedURLException with file URI

    - by Paul Reiners
    While executing the following code: doc = builder.parse(file); where doc is an instance of org.w3c.dom.Document and builder is an instance of javax.xml.parsers.DocumentBuilder, I'm getting the following exception: Exception in thread "main" java.net.MalformedURLException: unknown protocol: c at java.net.URL.<init>(Unknown Source) at java.net.URL.<init>(Unknown Source) at java.net.URL.<init>(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.setupCurrentEntity(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startEntity(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startDTDEntity(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDTDScannerImpl.setInputSource(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.next(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source) at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown Source) at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(Unknown Source) at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(Unknown Source) at javax.xml.parsers.DocumentBuilder.parse(Unknown Source) at com.acme.ItemToThetaValues.createFiles(ItemToThetaValues.java:47) It's choking on this line of the file: <!DOCTYPE questestinterop SYSTEM "C:\Program Files\Acme\parsers\acme_full.dtd"> I am not getting this error on my machine, while a user is getting it on his machine. We are both using version 6 of the Sun JRE. This error also occurs when he's uses double backslashes in the path instead of single backslashes and when he uses forward slashes instead of backslashes. First of all, is the XML correct? Is the path expressed correctly? Second of all, why is this error occurring on one computer but not on another?

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  • Looking for a very simple file-based CMS

    - by nfm
    I'm building a site for a friend for free, and am trying to work out a good way for her to be able to easily make updates. I haven't used any CMSs before. I was browsing the web today looking at some, and they all seem way too complicated for what I'm after. Basically, all I want is a really simple CMS that pulls together HTML snippets in particular subdirectories, and wraps them in header/footer HTML and inserts them into a template page in the appropriate section. I'm imagining a site layout something like this: / /index.php /blog_template.php /news_template.php /blog/ /blog/header.php /blog/footer.php /blog/my-first-blog.html /blog/blogs-rule.html /blog/... Say index.php contains div#blog. PHP would wrap each /blog/*.html file in /blog/header.php and blog/footer.php, and insert them into the div#blog as div#blog([0-9]*). I haven't been able to find anything this basic, and am one step away from throwing something together myself, but I'm a bit short on time at the moment and figured I'd post here first. Has anyone come across something like this? I don't want any DB, extensions, user accounts, installation, config, updates... just a simple file based solution. Thanks :) Forgot to mention - needs to be FOSS and run on Linux!

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  • Fastest Java way to remove the first/top line of a file (like a stack)

    - by christangrant
    I am trying to improve an external sort implementation in java. I have a bunch of BufferedReader objects open for temporary files. I repeatedly remove the top line from each of these files. This pushes the limits of the Java's Heap. I would like a more scalable method of doing this without loosing speed because of a bunch of constructor calls. One solution is to only open files when they are needed, then read the first line and then delete it. But I am afraid that this will be significantly slower. So using Java libraries what is the most efficient method of doing this. --Edit-- For external sort, the usual method is to break a large file up into several chunk files. Sort each of the chunks. And then treat the sorted files like buffers, pop the top item from each file, the smallest of all those is the global minimum. Then continue until for all items. http://en.wikipedia.org/wiki/External_sorting My temporary files (buffers) are basically BufferedReader objects. The operations performed on these files are the same as stack/queue operations (peek and pop, no push needed). I am trying to make these peek and pop operations more efficient. This is because using many BufferedReader objects takes up too much space.

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  • Online file storage similar to Amazon S3

    - by Joel G
    I am looking to code a file storage application in perl similar to amazon s3. I already have a amazon s3 clone that I found online called parkplace but its in ruby and is old also isn't built for high loads. I am not really sure what modules and programs I should use so id like some help picking them out. My requirements are listed below (yes I know there are lots but I could start simple then add more once I get it going): Easy API implementation for client side apps. (maybe RESTful but extras like mkdir and cp (?) Centralized database server for the USERDB (maybe PostgreSQL (?). Logging of all connections, bandwidth used, well pretty much everything to a centralized server (maybe PostgreSQL again (?). Easy server side configuration (config file(s) stored on the servers). Web based control panel for admin(s) and user(s) to show logs. (could work just running queries from the databases) Fast High Uptime Low memory usage Some sort of load distribution/load balancer (maybe a dns based or pound or perlbal or something else (?). Maybe a cache of some sort (memcached or parlbal or something else (?). Thanks in advance

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  • Read/Write/Find/Replace huge csv file

    - by notapipe
    I have a huge (4,5 GB) csv file.. I need to perform basic cut and paste, replace operations for some columns.. the data is pretty well organized.. the only problem is I cannot play with it with Excel because of the size (2000 rows, 550000 columns). here is some part of the data: ID,Affection,Sex,DRB1_1,DRB1_2,SENum,SEStatus,AntiCCP,RFUW,rs3094315,rs12562034,rs3934834,rs9442372,rs3737728 D0024949,0,F,0101,0401,SS,yes,?,?,A_A,A_A,G_G,G_G D0024302,0,F,0101,7,SN,yes,?,?,A_A,G_G,A_G,?_? D0023151,0,F,0101,11,SN,yes,?,?,A_A,G_G,G_G,G_G I need to remove 4th, 5th, 6th, 7th, 8th and 9th columns; I need to find every _ character from column 10 onwards and replace it with a space ( ) character; I need to replace every ? with zero (0); I need to replace every comma with a tab; I need to remove first row (that has column names; I need to replace every 0 with 1, every 1 with 2 and every ? with 0 in 2nd column; I need to replace F with 2, M with 1 and ? with 0 in 3rd column; so that in the resulting file the output reads: D0024949 1 2 A A A A G G G G D0024302 1 2 A A G G A G 0 0 D0023151 1 2 A A G G G G G G (both input and output should read one line per row, ne extra blank row) Is there a memory efficient way of doing that with java(and I need a code to do that) or a usable tool for playing with this large data so that I can easily apply Excel functionality..

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  • Looking for the log file on iPhone

    - by zp26
    Hi, I have a problem. I have the code below for save a data on file. I build my app on the device, and run. The result variable is TRUE, but i don't find the file on the my iPhone device. Can you help me? Thank and sorry for my english XP -(void)saveXML:(NSString*)name:(float)x:(float)y:(float)z{ NSMutableData *data = [NSMutableData data]; NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data]; [archiver setOutputFormat:NSPropertyListXMLFormat_v1_0]; [archiver encodeFloat:x forKey:@"x"]; [archiver encodeFloat:y forKey:@"y"]; [archiver encodeFloat:z forKey:@"z"]; [archiver encodeObject:name forKey:@"name"]; [archiver finishEncoding]; NSString* filePath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingPathComponent:@"XML Position"]; BOOL result = [data writeToFile:filePath atomically:YES]; if(result) [self updateTextView:@"success"]; [archiver release]; }

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  • How to delete duplicate/aggregate rows faster in a file using Java (no DB)

    - by S. Singh
    I have a 2GB big text file, it has 5 columns delimited by tab. A row will be called duplicate only if 4 out of 5 columns matches. Right now, I am doing dduping by first loading each coloumn in separate List , then iterating through lists, deleting the duplicate rows as it encountered and aggregating. The problem: it is taking more than 20 hours to process one file. I have 25 such files to process. Can anyone please share their experience, how they would go about doing such dduping? This dduping will be a throw away code. So, I was looking for some quick/dirty solution, to get job done as soon as possible. Here is my pseudo code (roughly) Iterate over the rows i=current_row_no. Iterate over the row no. i+1 to last_row if(col1 matches //find duplicate && col2 matches && col3 matches && col4 matches) { col5List.set(i,get col5); //aggregate } Duplicate example A and B will be duplicate A=(1,1,1,1,1), B=(1,1,1,1,2), C=(2,1,1,1,1) and output would be A=(1,1,1,1,1+2) C=(2,1,1,1,1) [notice that B has been kicked out]

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  • how to write binary copy of structure array to file

    - by cerr
    I would like to write a binary image of a structure array to a binary file. I have tried this so far: #include <stdio.h> #include <string.h> #define NUM 256 const char *fname="binary.bin"; typedef struct foo_s { int intA; int intB; char string[20]; }foo_t; void main (void) { foo_t bar[NUM]; bar[0].intA = 10; bar[0].intB = 999; strcpy(bar[0].string,"Hello World!"); Save(bar); printf("%s written succesfully!\n",fname); } int Save(foo_t* pData) { FILE *pFile; int ptr = 0; int itr = 0; pFile = fopen(fname, "w"); if (pFile == NULL) { printf("couldn't open %s\n", fname); return; } for (itr = 0; itr<NUM; itr++) { for (ptr=0; ptr<sizeof(foo_t); ptr++) { fputc((unsigned char)*((&pData[itr])+ptr), pFile); } fclose(pFile); } } but the compiler is saying aggregate value used where an integer was expected fputc((unsigned char)*((&pData[itr])+ptr), pFile); and I don't quite understand why, what am I doing wrong? Thanks!

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