QProcess unknown error

Question

I got strange problem. QProcess just not working!

And error is unknown.

I got global var in header

QProcess *importModule;

An I

Answer 1

startDetached() is a static method and doesn't operate on importModule at all. It starts a process and then stops caring. Thus the error()/errorState() in importModule has nothing to do with the startDetached() call. What you want is start(). However, as QProcess is asynchronous, nothing will have happened yet immediately after start() returns. You must connect to the started(), error() and finished() signals to learn about the result.

connect(importModule, SIGNAL(started()), this, SLOT(importModuleStarted()));
connect(importModule, SIGNAL(finished(int, QProcess::ExitStatus)), this, SLOT(importModuleFinished(int, QProcess::ExitStatus)));
CONNECT(importModule, SIGNAL(error(QProcess::ProcessError)), this, SLOT(importModuleError(QProcess::ProcessError)));
importModule->start(QStringLiteral("importdb_module"), QStringList());

Alternatively you can use the blocking wait functions:

importModule->start(QStringLiteral("importdb_module"), QStringList());
importModule->waitForStarted(); // waits until starting is completed
importModule->waitForFinished(); // waits until the process is finished

However, I strongly advise against using them in the main thread, as they block the UI then.