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Settings and macOS. Impossible to create a ini file...



  • Hello,

    I have a problem with Qt 5.15.2 and os X. When I try to save an ini file, the Settings.status() returns QSettings::NoError but I don't have any file in the indicated directory!

    Adding settings.sync() doesn't change anything...

    How to do ?

    Thanks !

    QString p = QStandardPaths::writableLocation(QStandardPaths::HomeLocation);
    
    QSettings settings(p + "/test.ini", QSettings::IniFormat);
    
    settings.setPath(QSettings::IniFormat, QSettings::UserScope, p);
    
    settings.beginGroup("Data");
    
    settings.setValue("a1", 0.0);
    settings.setValue("a2", 0.0);
    
    settings.endGroup();
    
    return settings.status();
    


  • @Francky033 pls read the documentation for the locations where does this ini files get's stored.
    https://doc.qt.io/qt-5/qsettings.html#platform-specific-notes

    QSettings constructor is using filename not the file path..

    If format is QSettings::IniFormat, fileName (first parameter) is the name of an INI file.
    https://doc.qt.io/qt-5/qsettings.html#QSettings-3

    QSettings settings(p + "/test.ini", QSettings::IniFormat);
    

    If you want to set the path for ini files set it before the object creation
    https://doc.qt.io/qt-5/qsettings.html#setPath
    read the warning mentioned in the Qt doc

    Warning: This function doesn't affect existing QSettings objects.
    

    @Francky033 here in the code QSettings object is created and then set the path for ini file.
    use QSettings::setPath() before the object creation.



  • Hello nagesh,

    I followed your instructions and looked at the doc.

    I put the setPath before the creation of the file and I use the name of the file in file without the path but I have the same result.
    In the log, I have a strange error message that tells me that the file is in read mode : Error opening for read : "No such file or directory".

    There is no problem with the file name or directory. Here, I try to write in the directory /users/user_name/Library/preferences

    Everything works fine when I launch the program from qtcreator, but it doesn't work anymore when I install the application. There is clearly a permissions problem...

    QString p = QStandardPaths::writableLocation(QStandardPaths::HomeLocation);
    
    QSettings::setPath(QSettings::IniFormat, QSettings::UserScope, p);
    
    QSettings settings("test.ini", QSettings::IniFormat);
    
    settings.beginGroup("Data");
    
    settings.setValue("a1", 0.0);
    settings.setValue("a2", 0.0);
    
    settings.endGroup();
    
    return settings.status();
    

  • Lifetime Qt Champion

    @Francky033 said in Settings and macOS. Impossible to create a ini file...:

    tells me that the file is in read mode : Error opening for read : "No such file or directory".

    It actually tells that the file does not exist.
    You should check what the whole path looks like (value of variable p).



  • Ah, I think I found the problem. The directory QStandardPaths::HomeLocation doesn't seem to be writable. But if I use QStandardPaths::AppLocalDataLocation. Everything works !

    But QStandardPaths::writableLocation(QStandardPaths::HomeLocation) should allow write access. Why is this not the case?


  • Lifetime Qt Champion

    @Francky033 said in Settings and macOS. Impossible to create a ini file...:

    Why is this not the case?

    Could be a bug in Qt. You can check Qt bug tracker and file a bug if it is not already reported.


  • Lifetime Qt Champion

    Hi,

    @Francky033 said in Settings and macOS. Impossible to create a ini file...:

    Ah, I think I found the problem. The directory QStandardPaths::HomeLocation doesn't seem to be writable. But if I use QStandardPaths::AppLocalDataLocation. Everything works !

    But QStandardPaths::writableLocation(QStandardPaths::HomeLocation) should allow write access. Why is this not the case?

    What exact path are you getting that fails ?



    • What exact path are you getting that fails ?

    /Users/my_user_name
    ~/Library/Preferences/

    Another strange point. The save only works if I write :

    QSettings settings(file, QSettings::IniFormat);
    (with file containing the complete path )

    and if in the setPath I use the full path of the file rather than the directory in which I want to save :

    QString p = QStandardPaths::writableLocation(QStandardPaths::AppLocalDataLocation);
    
    QString file = p +"/test.ini";
    
    QSettings::setPath(QSettings::IniFormat, QSettings::UserScope, file);
    
    QSettings settings(file, QSettings::IniFormat);
    
    settings.beginGroup("Data");
    
    settings.setValue("a1", 0.0);
    settings.setValue("a2", 0.0);
    
    settings.endGroup();
    
    return settings.status();
    

    This code works but I don't know why it works in fact.



  • No, in fact, it does not work anymore.
    I always get the message "No such file or directory" when I run the application in a terminal but the result of qsettins::status() is No::ERROR



  • In fact, my code is a bit more complicated. I'm calling a getSaveFileName box just before. Could this have an effect?

    QString file = QFileDialog::getSaveFileName(
    		this, tr("Save a configuration file..."), QStandardPaths::writableLocation(QStandardPaths::AppLocalDataLocation),
    		"configuration file (*.ini)");
    
    QSettings::setPath(QSettings::IniFormat, QSettings::UserScope, file);
    
    QSettings settings(file, QSettings::IniFormat);
    
    settings.beginGroup("Data");
    
    settings.setValue("a1", 0.0);
    settings.setValue("a2", 0.0);
    
    settings.endGroup();
    
    return settings.status();
    

  • Lifetime Qt Champion

    @Francky033 said in Settings and macOS. Impossible to create a ini file...:

    QSettings::setPath(QSettings::IniFormat, QSettings::UserScope, file);

    Shouldn't you actually provide a path to a folder, not to a file? So, using setPath you set the folder where ini files should be stored, then if you create a QSettings instance you pass the name of an ini file which then stored in the folder specified by setPath.



  • I modified my code this way but it still doesn't work...

    QString file = QFileDialog::getSaveFileName(
    		this, tr("Save a configuration file..."), QStandardPaths::writableLocation(QStandardPaths::AppLocalDataLocation), "configuration file (*.ini)");
    
    QString d = file.left(file .lastIndexOf("/"));
    
    QSettings::setPath(QSettings::IniFormat, QSettings::UserScope, d);
    
    QSettings settings(file, QSettings::IniFormat);
    
    settings.beginGroup("Data");
    
    settings.setValue("a1", 0.0);
    settings.setValue("a2", 0.0);
    
    settings.endGroup();
    
    return settings.status();
    

  • Lifetime Qt Champion

    @Francky033 said in Settings and macOS. Impossible to create a ini file...:

    QSettings settings(file, QSettings::IniFormat);

    file should be only file name here.

    "QString d = file.left(file .lastIndexOf("/"));" - use QFileInfo::absolutePath() to get the folder without file name.



  • jsulm, I modified my code this way, but no effect

    QString file = QFileDialog::getSaveFileName(
    		this, tr("Save a configuration file..."), QStandardPaths::writableLocation(QStandardPaths::AppLocalDataLocation), "configuration file (*.ini)");
    
    QFileInfo f(file);
    
    QString d = f.absoluteFilePath();
    QString name = f.fileName();
    
    QSettings::setPath(QSettings::IniFormat, QSettings::UserScope, d);
    
    QSettings settings(f, QSettings::IniFormat);
    
    settings.beginGroup("Data");
    
    settings.setValue("a1", 0.0);
    settings.setValue("a2", 0.0);
    
    settings.endGroup();
    
    return settings.status();
    

  • Lifetime Qt Champion

    But why are you using setPath at all ?



  • I removed the setPath and I still have the same result. When I start the program from qtcreator, everything works. But it does not work anymore when the program is installed on the OS.
    This seems to me to be a permissions problem. But how to solve this?


  • Lifetime Qt Champion

    Did you used macdeployqt before running it outside of Qt ?



  • @Francky033 If it is permission problem OS should ask user upon the startup if read/write permission to folder should be granted (like it happens every time I deploy my software).
    It's ok if you run it from QtCreator as child process of QtCreator is allowed standard access to the home tree.



  • SGaist : Yes !

    artwaw : But if it is not a problem of permissions, where can the problem come from? What also surprises me is the message "No such file or directory" that appears in the log when the settings variable is created and the NoERROR as result of settings::status() at the end of the record.


  • Moderators

    I believe you've been let a stray, this code is taken from my working application:

    QString appDataPath = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation) +QString("/");
    
    QString settingsPath = appDataPath + QString("data/Settings.ini");
    
    //And used this way
    auto settings = new QSettings(settingsPath(), QSettings::IniFormat);
    

    this results in a directory path

    qDebug() << Q_FUNC_INFO << settings->fileName();
    

    "/Users/jonashilk/Library/Application Support/CompanyName/Applicationname/data/Settings.ini"



  • @Francky033 I don't have idea what's happening in your system. I'd try to debug the problem by hardcoding known path to the file though, like /Users/[username]/settings.ini or something.



  • Hello everyone and thanks for your help!

    I finally discovered the problem: I had to put a settings.sync() before the settings.status();

    While the sync function doesn't seem to have any effect under Windows, Android and linux, it seems necessary to use it under macOS.

    The documentation is a bit vague on this: "This function is called automatically from QSettings's destructor and by the event loop at regular intervals, so you normally don't need to call it yourself."

    My problem is solved and I hope this can give a clue to people in the same situation as me. Thanks to the Qt forum and its members!



  • Hello,

    I am again confronted with the same problem. Everything was working fine and the next day, no directory was accessible for saving using this piece of code!
    When the save box opens, I noticed that all the elements in the directory (including .ini files) are grayed out...
    What I don't understand is the extremely capricious result of this function (which is so simple). One day it works, the next day it doesn't...

    Is it a bug in Qt?

    Have a nice day!

    Francky033


  • Lifetime Qt Champion

    Did you restart a build from scratch ?
    Re-run macdeployqt on your app bundle ?

    Apple has introduced several security feature with regard to accessing the user environnement which might trigger here.


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