Check file if the file is writable or used by another process

[Naahmi]

Hello,

is there a way to check if the file is used by another process like soffice?
Under Windows it works perfect but under mac/linux is doesnt work. I think mac/linux doesn't make the file only readable.

My Testcase:

QString fileName = childElement.text();
         fileName = QDir::tempPath() + "/" + fileName;
 
         for(int i=0; i < 100; i++)
         {
             QFile file(fileName);
 
             if(file.open(QIODevice::WriteOnly))
             {
                 qDebug() << "JA";
             } else {
                 qDebug() << "NEIN";
             }

QString fileName = childElement.text();
         fileName = QDir::tempPath() + "/" + fileName;

         for(int i=0; i < 100; i++)
         {
             QFile file(fileName);

             if(file.open(QIODevice::WriteOnly))
             {
                 qDebug() << "JA";
             } else {
                 qDebug() << "NEIN";
             }

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[Charvi]

Unfortunately there is no file locking in Unix.
What you can do is call a system command and use a combination of fuser and grep to find if some other process is using the file.

[Naahmi]

Unfortunately there is no file locking in Unix.
What you can do is call a system command and use a combination of fuser and grep to find if some other process is using the file.

unix create a ".~lock.filename#" logfile. but i have hope there is a better way to handle this. We are open the file with QDesktopService:penUrl(...);

[wysota]

Unix doesn't create any lock files. If an application doesn't lock the file for exclusive access (and on Unix applications rarely do that), there is no way of knowing if a file is open other than processing the /proc tree (if it exists and you have access to it).