BASH: Is there any way to cut string returned by function using shell expansion tricks?

Question

What i have:

MUSTBE_TIME=`GetPastHours $[$i-1]|cut -c 1-2`

It works. But is there away to do something like this ?

MUSTBE_TIME=${`GetPastHours $[$i-1]`:1:2}

Thanks,

Answer 1

(Incidentally, $[...] is an obsolete syntax; you should use $((...)) instead.)

bash doesn't allow nesting of parameter expansions, you can can't use the result of a command substitution as if it were a parameter. You can use a combination of the read command and process substitution, though.

read -n 2 MUSTBE_TIME < <(GetPastHours $((i-1)))