GNU parallel combination of array arguments?

Question

I have a bash function:

println(){echo "$1" "$2" "$3"}

and

export -f println

I want to use GNU parallel to run println. The command should take inputs of the following arrays:

a1=(a b c) 

a2=(x y)

a3=(z1 z2)

It should output the follows:

   a x a3
   a y a3
   b x a3
   b y a3
   c x a3
   c y a3

Which command can do that? I expect the command like:

 parallel ... println ... a1 ... a2 .... a3

Thank you!

KamilCuk · Accepted Answer · 2021-07-24 18:42:52Z

5

Just put ::: in between:

$ parallel println ::: "${a1[@]}" ::: "${a2[@]}" ::: "${a3[@]}"
a y z1
a x z1
a y z2
a x z2
b x z2
b x z1
b y z2
b y z1
c x z2
c x z1
c y z1
c y z2

The println(){echo "$1" "$2" "$3"} is invalid, it needs to be println(){ echo "$1" "$2" "$3"; }.

answered Jul 24, 2021 at 9:50

KamilCuk

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nezabudka · Accepted Answer · 2021-07-24 11:09:44Z

1

Can be applied Brace Expansion in bash with variable IFS

(IFS=,; eval printf %s "{${a1[*]}}\ {${a2[*]}}\ {${a3[*]}}\$'\n'")

a x z1
a x z2
a y z1
a y z2
b x z1
b x z2
b y z1
b y z2
c x z1
c x z2
c y z1
c y z2

(...) - We execute in a subshell so as not to return the value to the IFS variable.

Or exactly like in your example:

(IFS=,; eval printf %s "{${a1[*]}}\ {${a2[*]}}\ a3\$'\n'")
a x a3
a y a3
b x a3
b y a3
c x a3
c y a3

answered Jul 24, 2021 at 10:50

nezabudka

2,4568 silver badges15 bronze badges

2 Answers 2