Passing arrays as parameters in bash

Question

How can I pass an array as parameter to a bash function?

Note: After not finding an answer here on SO, I posted my somewhat crude sollution myself. It allows for only one array being passed, and it being the last element of the parameter list. Actually, it is not passing the array at all, but a list of its elements, which are re-assembled into an array by called_function(), but it worked for me. If someone knows a better way, feel free to add it here.

Answer 1

calling_function()
{
    variable="a"
    array=( "x", "y", "z" )
    called_function "${variable}" "${array[@]}"
}

called_function()
{
    local_variable="${1}"
    shift
    local_array=("${@}")
}

Improved by TheBonsai, thanks.

Answer 2

Here you have nice reference and tons of examples.

Answer 3

DevSolar's answer has one point I don't understand (maybe he has a specific reason to do so, but I can't think of one): He sets the array from the positional parameters element by element, iterative.

An easier approuch would be

called_function()
{
  ...
  # do everything like shown by DevSolar
  ...

  # now get a copy of the positional parameters
  local_array=("$@")
  ...
}

Answer 4

this doesnt work if there are spaces in one array element

Answer 5

You can pass multiple arrays as arguments using something like this:

takes_ary_as_arg()
{
    declare -a argAry1=("${!1}")
    echo "${argAry1[@]}"

    declare -a argAry2=("${!2}")
    echo "${argAry2[@]}"
}
try_with_local_arys()
{
    # array variables could have local scope
    local descTable=(
        "sli4-iread"
        "sli4-iwrite"
        "sli3-iread"
        "sli3-iwrite"
    )
    local optsTable=(
        "--msix  --iread"
        "--msix  --iwrite"
        "--msi   --iread"
        "--msi   --iwrite"
    )
    takes_ary_as_arg descTable[@] optsTable[@]
}
try_with_local_arys

will echo:

sli4-iread sli4-iwrite sli3-iread sli3-iwrite
--msix --iread --msix --iwrite --msi --iread --msi --iwrite