[Solved] How to read sysfs entries from qt and put it into qprogressbar?

[Ajith_P_V]

Hi,
I have a small application in which I need to get the sysfs (say example '/sys/class/power_supply/modelgauge_battery/capacity') details and put that one into QProgressbar.
Since, sysfs entries are treated as files under linux, I have tried with accessing the sysfs entries using QFile.
i.e. QFile file("/sys/class/power_supply/modelgauge_battery/capacity");
Now, I want to read the value of the file and that value I need to pass into QProgressbar's value as below
progressBar->setValue(<value_read_from_file>)

I tried some experiments, but nothing yield to the desired result. Could anyone can help me to figure out how to achieve this.
PS: the value which I need in this case is integer (setValue( ) accepts integer).

Looking forward to your reply.
Thank you in advance,
Ajith P V

[jsulm]

Can you post your code?
What is the content of /sys/class/power_supply/modelgauge_battery/capacity?
Reading from a file is as simple as file.readAll() and converting the QByteArray to what ever you need.
If the content of the file is an integer number then you can do: file.readAll().toInt()

[Ajith_P_V]

@jsulm Thank you for your reply.
/sys/class/power_supply/modelgauge_battery/capacity shows the battery percentage in number when we run it from a console (terminal) with cat command. I would like to know whether I can take the 'sysfs' entries like how I'm doing.
Please see my code snippet below (I'm using Qt Creator):

QFile file("/sys/class/power_supply/modelgauge_battery/capacity");
if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
return;
QDataStream in(&file);
int battery_value;
in >> battery_value;
ui->progressBar->setValue(battery_value);

I also tried file.readAll( ).toInt( ) earlier but the Progressbar shown 0 always (meaning not taking or invalid value I guess) in all cases.

[jsulm]

Well, there is probably a new-line at the end of the file content, try this:
file.readAll( ).trimmed().toInt( );

[Ajith_P_V]

@jsulm said:

file.readAll( ).trimmed().toInt( );

Wow! just wow! It got solved :)

[jsulm]

Nice to hear that it works now :-)