setstandardoutputprocess vs piped shell script

i need to read out the signal strength of a modem to my qt program like this:

Code:

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echo at+csq > /dev/ttyUSB2 | head -n 4 /dev/ttyUSB2

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which is the best to use:

Qprocess::setStandardOutputProcess with two Qprocesses, one for "echo at+csq > /dev/ttyUSB2" and one for "head -n 4 /dev/ttyUSB2 " or a single Qprocess that runs a shell script with pipe

Like this

Code:

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#!/bin/bash
 
echo at+csq > /dev/ttyUSB2 | head -n 4 /dev/ttyUSB2

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Neither of them. If you have a native C++ application, you should not depend on bash. Open the device directly in Qt.

How do i do that?

I think QFile is your friend.