I am using two instances of QProcess. In some portions of my code I need process1 to redirect its output to process2.
By following Qt documentation I can use QProcess.setStandardOutput(), which is great. But, later on I have to disable this in code.
How do I redirect its output to the default behavior (stdout)? I have tried process1 = QProcess(), but it did not work.
process1 = QProcess()
process2 = QProcess()
process1.setStandardOutputProcess(process2)
process1.start("command1")
process2.start("command2")
process1.setStandardOutputProcess(QProcess())
works but is that the correct way of redistricting? Or am I creating a new "uneccessry" object?
After reporting this as a bug on Qt bug tracker.
I have received the following reply:
That is a limitation of Qt,
QProcess::setStandardOutputProcess(Qprocess *destination)expects a non-null pointer; it is not meant to be changed at runtime.
My workaround to this issue was to use process1.setStandardOutputProcess(QProcess()).
EDIT
I asked if there is a workaround and received the following reply
Is there a recommended workaround?
He replied
No. It is not designed to allow for a change of device (since there are most likely I/O buffers involved). Similarly, when doing something like
ls -l | fgrep "bla"
in the shell, there is no way the change the 2nd process in mid-flight, either.