Weird behavior of QProcess and multiple qoutes

[jsulm]

@Guanhong Then add proper error handling and also read from std error of your process to see whether it prints any errors.

[Guanhong]

@jsulm
QString strResult4 = prcsWlan4.readAllStandardOutput();
strResult4 is FAIL

[jsulm]

@Guanhong said in Weird behavior of QProcess and multiple qoutes:

readAllStandardOutput()

I was talking about std ERROR (https://doc.qt.io/qt-5/qprocess.html#readAllStandardError)...

[Christian Ehrlicher]

Please run it on the command line. Maybe you don't have the proper privileges.

[Guanhong]

@Christian-Ehrlicher
I have run it on the command line, it is no problem.

[Christian Ehrlicher]

@Guanhong Please show how you run it on the command line

[Guanhong]

@Guanhong said in Weird behavior of QProcess and multiple qoutes:

<

wpa_cli -i wlan0 set_network 1 ssid '"hima24g"'
I run it on an Ubuntu console, and it can run successfully

[jsulm]

@Guanhong said in Weird behavior of QProcess and multiple qoutes:

wpa_cli -i wlan0 set_network 1 ssid '"hima24g"'

wpa_cli -i wlan0 set_network 1 ssid hima24g

should work just as good

[Christian Ehrlicher]

set_network 1

is not

"set_network" << "0"

[Guanhong]

wpa_cli -i wlan0 set_network 1 ssid hima24g
without quotes, it does not work on my console.

set_network 1 or set_network 0 does not matter.
It depends.

[jsulm]

@Guanhong So, did you try to print out https://doc.qt.io/qt-5/qprocess.html#readAllStandardError ?

[Christian Ehrlicher]

Looks like wpa_cli really needs additional double quotes... strange and weird program (see google for a lot of confusion due to this behavior).
So it must be

arguments << "-i" << "wlan0" << "set_network" << "0"<< "ssid" << "\"" + strSSID + "\"";

[Guanhong]

@Christian-Ehrlicher
this command includes not only double quotes but also single quotes outside. Can QProcess handle it？

[Christian Ehrlicher]

The outer quotes are only needed so the inner ones are not removed by the shell.

[Guanhong]

@Christian-Ehrlicher
I don't think so. both quotes are necessary, without either, the command doesn't work on command line.

[JonB]

@Guanhong
Do you understand that, certainly quote-wise, what you type into a shell/command-line is not the same as what you would put into the QStringList for the arguments to QProcess::start()?

Meanwhile if you helped us by using the forum's Code toolbutton around what you are entering on the command-line it would be a lot easier to read/understand.

[Christian Ehrlicher]

@Guanhong said in Weird behavior of QProcess and multiple qoutes:

I don't think so. both quotes are necessary, without either, the command doesn't work on command line.

I'm giving up.... don't know how often I must explain that your shell/command line removes the outer quotes...

[Guanhong]

@Christian-Ehrlicher
thank you very much ,
arguments << "-i" << "wlan0" << "set_network" << "0"<< "ssid" << """ + strSSID + """;
works.

sorry for my poor understanding.