Create an array of all possible combinations among N arrays

Question

I have a script that runs another bash script with N optional parameters, such as:

./my_script.sh --param_1 <value> --param_2 <value> ... --param_N <value>

In my main script, i would like to have N arrays with possible values for each of the N parameters, such as:

PARAM_1_VALS=(1 10 50)
PARAM_2_VALS=(50 10 20)
PARAM_N_VALS=("a" "b" "c")

I'd like to know if there is any function that, given an array of N arrays, returns all the possible combinations among those arrays (ex: (1 50 "a"), (1 50 "b"), ..., (50 20 "c"))

The desired script would be:

all_combinations=get_all_combinations(params_array)
for combination in ${all_combinations[@]}; do
   #execute my_script.sh with combination
done

My current solution is performing badly since i'm just iterating through all arrays in nested loops to get all values. I would like to remove the nested loops and look for a better approach.

ps: what i'm looking is very similar to python's itertools.combinations() solution

Thanks

Answer 1

You can use brace expansion, but it only works on literal values, i.e. you can't use variables inside the braces.

for c in --param1\ {1,10,50}\ --param2\ {50,10,20}\ --param3\ {a,b,c} ; do
    echo "$c"
done