Reading a file into variable without newlines

Question

I am not expert with bash but I would imagine this would be a simple script. I am trying to read a file with a few lines into a single bash variable without the new lines.

My current script reads them in but keeps the presence of newlines

options=$(<vm.options)
echo "$options"

The file looks something like this:

-Random 1
-Letters2
-Occur 3
-In
-Passwords9

The script would read this into a variable where its output would look like:

-Random 1 -Letters2 -Occur 3 -In -Passwords9

Answer 1

You can do search/replace in bash after reading file content:

options=$(<vm.options)
# replace \n with space
options="${options//$'\n'/ }"

Now examine options variable:

declare -p options

declare -- options="-Random 1 -Letters2 -Occur 3 -In -Passwords9"

Answer 2

This also produces the desired output:

echo "\
-Random 1
-Letters2
-Occur 3
-In
-Passwords9" > tmp

var=$(cat tmp | tr -s '\n' ' ')

echo $var

resulting in:

-Random 1 -Letters2 -Occur 3 -In -Passwords9

the part with cat is not pretty (and may break in specific instances) but it works for this case.