How to pass quoted parameters to another program

Question

In a bash script, I need to pass a parameter to another program. The parameter has spaces in so must be quoted. Everything works fine in this simple case 1:

/bin         


        

Answer 1

Use an array; this is why they were introduced.

FOO="ghi"
# Contains one element, but not the literal quotes
DEFAULTS=(--param="abc def $FOO")
# command gets 1 argument, the single element of the array
/some/command "${DEFAULTS[@]}"

# Two elements
DEFAULTS=(--param="abc def $FOO" --other="foo bar")
# command gets 2 arguments
/some/command "${DEFAULTS[@]}"

Answer 2

You are almost there. You just have to put the $DEFAULTS into double quotes so that bash doesn't do the word spliting.

DEFAULTS='param="ac def ghi"'
perl -le'print $ARGV[0]' "$DEFAULTS"

Output:

param="ac def ghi"