read-write to stdin-stdout or to a file?

[Pedro Zorzenon Neto]

Hi list,

   I wrote a program that needs to run setuid root due to direct hardware 
access (Package: avrprog).

   This program needs to read data from a file and also write to other file.

   I could use some options like this:

      $ avrprog -i input.data -o output.data

   But I chose to use stdin/stdout instead.

      $ avrprog < input.data > output.data

   Than I don't need to check if the user has permission to read/write that 
file, don't need to check for symlink... because the shell will do this for me.
   
   Is this right? Did I make the right option when I decided to use 
stdin/stdout.

       Thanks in advance,
       Pedro

Note: user messages and error messages go to stderr.