Bash Sleep vs crontab and bash serial port
I've got a couple of questions that I need some advice on.
1. I need to have a piece of software running in the background as root, to make some system changes based on what it finds in a file. I was either going to run a script on startup and then sleep the script for a minute, or going to set the script to run from cron. Does anyone know of any performance issues to doing it either way?
2. I need to do some basic RS232 through the serial port. It will literally be one byte out and then reading a reply of one byte in. Can bash do serial comms, if so does anyone have some source code or a website with details?
I'm trying to stay away from doing some C, but if I have no choice then... I'd really like to do it in bash.