The Bash FAQ has a whole entry about calling by reference / indirection.

In the simple case, a better alternative to the eval suggested by other answers, that makes the quoting much easier.

func() {
    local retvar=$1
    printf -v "$retvar"  '%s ' "${@:2}"  # concat all the remaining args
}

Bash-completion (the code that runs when you hit tab) has switched over to printf -v instead of eval for its internal functions, because it's more readable and probably faster.

For returning arrays, the Bash FAQ suggests using read -a to read into sequential array indices of an array variable:

# Bash
aref=realarray
IFS=' ' read -d '' -ra "$aref" <<<'words go into array elements'

Bash 4.3 introduced a feature that makes call-by-reference massively more convenient. Bash 4.3 is still new-ish (2014).

func () {
    typeset -n ref1=$1   # ref1 is a nameref variable.
    shift   # remove the var name from the positional parameters
    echo "${!ref1} = $ref1"  # prints the name and contents of the real variable
    ref1=( "foo" "bar" "$@" )  # sets the caller's variable.
}

Note that the wording of the bash man page is slightly confusing. It says the -n attribute can't be applied to array variables. This means you can't have an array of references, but you can have a reference to an array.

The Bash FAQ has a whole entry about calling by reference / indirection.

In the simple case, a better alternative to the eval suggested by other answers, that makes the quoting much easier.

func() {  # set the caller's simple non-array variable
    local retvar=$1
    printf -v "$retvar"  '%s ' "${@:2}"  # concat all the remaining args
}

Bash-completion (the code that runs when you hit tab) has switched over to printf -v instead of eval for its internal functions, because it's more readable and probably faster.

For returning arrays, the Bash FAQ suggests using read -a to read into sequential array indices of an array variable:

# Bash
aref=realarray
IFS=' ' read -d '' -ra "$aref" <<<'words go into array elements'

Bash 4.3 introduced a feature that makes call-by-reference massively more convenient. Bash 4.3 is still new-ish (2014).

func () { # return an array in a var named by the caller
    typeset -n ref1=$1   # ref1 is a nameref variable.
    shift   # remove the var name from the positional parameters
    echo "${!ref1} = $ref1"  # prints the name and contents of the real variable
    ref1=( "foo" "bar" "$@" )  # sets the caller's variable.
}

Note that the wording of the bash man page is slightly confusing. It says the -n attribute can't be applied to array variables. This means you can't have an array of references, but you can have a reference to an array.

The Bash FAQ has a whole entry about calling by reference / indirection.

In the simple case, a better alternative to the eval suggested by other answers, that makes the quoting much easier.

func() {
    local retvar=$1
    printf -v "$retvar"  '%s ' "${@:2}"  # concat all the remaining args
}

Bash-completion (the code that runs when you hit tab) has switched over to printf -v instead of eval for its internal functions, because it's more readable and probably faster.

For returning arrays, the Bash FAQ suggests using read -a to read into sequential array indices of an array variable:

# Bash
aref=realarray
IFS=' ' read -d '' -ra "$aref" <<<'words go into array elements'

The Bash FAQ has a whole entry about calling by reference / indirection.

In the simple case, a better alternative to the eval suggested by other answers, that makes the quoting much easier.

func() {
    local retvar=$1
    printf -v "$retvar"  '%s ' "${@:2}"  # concat all the remaining args
}

Bash-completion (the code that runs when you hit tab) has switched over to printf -v instead of eval for its internal functions, because it's more readable and probably faster.

For returning arrays, the Bash FAQ suggests using read -a to read into sequential array indices of an array variable:

# Bash
aref=realarray
IFS=' ' read -d '' -ra "$aref" <<<'words go into array elements'

Bash 4.3 introduced a feature that makes call-by-reference massively more convenient. Bash 4.3 is still new-ish (2014).

func () {
    typeset -n ref1=$1   # ref1 is a nameref variable.
    shift   # remove the var name from the positional parameters
    echo "${!ref1} = $ref1"  # prints the name and contents of the real variable
    ref1=( "foo" "bar" "$@" )  # sets the caller's variable.
}

Note that the wording of the bash man page is slightly confusing. It says the -n attribute can't be applied to array variables. This means you can't have an array of references, but you can have a reference to an array.