Nios II, nonblocking i/o, anyone

Hi NiosII users,

I also need a nonblocking uart read, but I am having some trouble with the defined switches.

// if I open a stream in this way:

fp = fopen("/dev/uart1","r+");

//then

fread(buff,sizeof(char),1,fp);

// it works OK but blocks until a character is available.

// but if I use the defined switch (from fcntl.h)

fp = fopen("/dev/uart1","O_RDWR");

// it dosnt read or write!

I wish to use:

fp = fopen("/dev/uart1","O_RDWR|O_NONBLOCK");

By the way, the second argument to fopen should be of type 'const char*' (eg. "O_RDWR|O_NONBLOCK"), no

t an integer produced by: O_RDWR|O_NONBLOCK

fp = fopen("/dev/uart1",O_RDWR);

The above line will compile with a (implicit cast) warning, but should not give correct operation.

Any ideas?