How to run a command in the background and get no output?

Question

I wrote two shell scripts a.sh and b.sh. In a.sh and b.sh I have a infinite for loop and they print some output to the te

Answer 1

Redirect the output to a file like this:

./a.sh > somefile 2>&1 &

This will redirect both stdout and stderr to the same file. If you want to redirect stdout and stderr to two different files use this:

./a.sh > stdoutfile 2> stderrfile &

You can use /dev/null as one or both of the files if you don't care about the stdout and/or stderr.

See bash manpage for details about redirections.