Passing a variable in System() c++ - c++

Question

if (t.elapsed_millisecs() > 500) {
system(("powershell(Get - WmiObject - Namespace root / WMI - Class WmiMonitorBrightnessMethods).WmiSetBrightness(1, " + brightness + string(")")).c_str());
t = {};
}
brightness is just an int that can be set from 1 to 100
I'm trying to change the brightness over a certain amount of time but I'm having problem with system() function. When the program tries to execute the system() function, the cmd outputs " '_' is not recognized as an internal or external command, operable program or batch file."
My question is how do you pass a variable to the system function correctly?

Answer 1

You are taking liberty with spaces in your example.
This one runs OK:
int brightness = 42;
string s = "powershell(Get-WmiObject -Namespace root/WMI -Class WmiMonitorBrightnessMethods).WmiSetBrightness(1, ";
s += to_string(brightness);
s += ")";
cout << s;
system(s.c_str());
It doesn't change the brightness though, but I don't know WMI...
I can run this in PowerShell console:
$myMonitor = Get-WmiObject -Namespace root\wmi -Class WmiMonitorBrightnessMethods
$myMonitor.wmisetbrightness(3,50)
Same result - no errors, no effect.
UPDATE:
It works! (I was testing over Remote Desktop at first)