How to redirect Lynux "system" call output to app

Anonymous_Banned275

I am getting little " gun shy" to ask questions...
please JUST ignore my post if I asked this one, two or three years before....

I need to output "system" call to both console and my app - for user info / processing.

I want to learn more about "std" hence I am NOT interested in other options, likers QProcess etc.

int RESULT = system(" echo q  | sudo -S hcitool info 98:D3:31:F8:39:33 ") ;

This is for TEST "generating error " only

     QProcess *QP = new QProcess();
                           QP->start(" echo q  | sudo -S hcitool info 98:D3:31:F8:39:33 ") ;

Here is current console output - both "progress" and "error".
I need to put both to app.

Here is a "good " output

Requesting information ...
Can't create connection: Operation not permitted
"\u0000"
"void MainWindow_Bluewtoothctl_Dialog::on_pushButton_19_clicked()  @ line  6727"
" echo q  | sudo -S hcitool info 98:D3:31:F8:39:33 "
"void MainWindow_Bluewtoothctl_Dialog::on_pushButton_19_clicked()  @ line  6743"
[sudo] password for nov25-1: Requesting information ...
	BD Address:  98:D3:31:F8:39:33
	OUI Company: Shenzhen Bolutek Technology Co.,Ltd. (98-D3-31)
	Device Name: SPP-CA
	LMP Version: 2.1 (0x4) LMP Subversion: 0x1060
	Manufacturer: Cambridge Silicon Radio (10)
	Features page 0: 0xbf 0xc6 0x8d 0x78 0x18 0x1e 0x79 0x83
		<3-slot packets> <5-slot packets> <encryption> <slot offset>

Here with error message

Requesting information ...
Can't create connection: Operation not permitted

JonB

@AnneRanch
In this post you say " NOT interested in other options, likers QProcess". In your other post at https://forum.qt.io/topic/154638/help-to-analyze-convert-command-string you say "I need to use QProcess defined as". Let's assume you do want to know how to do equivalent of system() with QProcess.

system() takes a string, like you would type into a shell/command prompt, and passes it to a shell to execute. It uses /bin/sh as the shell. And that accepts /bin/sh -c "command_line_here" So the direct equivalent for your command using QProcess::start() is:

QP->start("/bin/sh", { "-c", "echo q  | sudo -S hcitool info 98:D3:31:F8:39:33" } );

Note that whatever your desired command line is it must be passed as a single argument after the -c first argument.

I don't have Qt6, you may do. There you might find that the newly introduced startCommand() method does the shell for you, I don't know. So

QP->startCommand("echo q  | sudo -S hcitool info 98:D3:31:F8:39:33" } );

might work. But the first case with sh -c definitely works.