参考
proc = new QProcess(this);
connect(proc, SIGNAL(readyReadStandardOutput()), this, SLOT(readFromStdout()));
connect(proc, SIGNAL(readyReadStandardError()), this, SLOT(readFromStderr()));
connect(proc, SIGNAL(finished(int, QProcess::ExitStatus)), this, SLOT(done(int, QProcess::ExitStatus)));