Open a character device

[A Former User]

Hai, We created character device in dev/ folder.

from normal c application to open device in this folder we use open() system call, read the data from that using read().

my question is from Qt how can I open the device and read the data from that device?

I tired using QFile, but it is not opened.

can any one give some example regarding this
Thanks in advance

[mlong]

Is there possibly a permissions problem with the device you created? Is it readable by the user which is running the app?

Can you show a snippet of your code where you're trying to open and read from the device?

[A Former User]

@

QFile *file = new QFile("/dev/fp");
if(!file->open(QFile::ReadWrite))
{
qDebug()<<"file not opened\n";
}
@

this is tested on desktop, but my application is in embedded development board

[mlong]

How about the file permissions on /dev/fp are they reasonable for the user?

[A Former User]

its not readable.

[mlong]

Do you need to chmod a+r /dev/fp then?

[A Former User]

we have already root privileges in dev folder. but when i open from qt its not opened that file any thing different?