Best way to create list of parameters from string

Question

I have a variable with space separated list of paths. I need to send these paths to a program as a parameter like this script.sh -i /dir1 -i /dir2. What is the best way to create such parameter list? Something like $(echo "$paths" | sed 's|\([^[:space:]]\+\)|-i \1|g) will work but it's unreadable given the fact that it's part of the makefile.

Answer 1

list="one two three"
for i in $list; do params="$params -i $i"; done
script.sh $params

You will have troubles with paths with spaces, using : as paths separator is better

Answer 2

use bash arrays

paths="/dir1 /dir2"
params=()
for path in $paths; do params+=( -i $path ); done
script.sh "${params[@]}"