Hi

I had write a program using I/O port in it but
i don't know how i can find out the port number to use in my program
spectioally com ports number

if linux has a file to finding out the port number please help me




I have read the /proc/ioports but this file doesn't contain
more information about my problem


thanks

It depends on what you mean by I/O port number.

Typically you mean the hardware port numbers which run from 0000 to ffff and control I/O between the processor and various hardware devices (that's a simplified view). In which case /proc/ioports will list the currently assigned ports.

You mention "com"; do you mean DOS-style COM0, COM1, COM2 etc? In linux these are called serial TTY devices and are listed in ioports as "serial", "serial1" etc. They can also be accessed through /dev/ttyS0, /dev/ttyS1 and so on. You may find it easier to use the device files because then you won't need explicit root access.

If that doesn't help, then perhaps you could explain in more detail what kind of IO port number you are actually wanting (and perhaps what you want it for)?

Hope that helps,

—Robert J Lee