Is there in bash scripts a way of using variables to specify different bash arrays [duplicate]

Question

For example in this simple script

    #!/bin/bash
    
    declare -a MYARRAY1
    declare -a MYARRAY2
    
    function updatearray {
    ARRAY=$1
    VALUE=$2
    
    $ARRAY+=$VALUE
    
    }

    updatearray MYARRAY1  "yyyy "
    updatearray MYARRAY2  "bbbb "
    
    echo "${MYARRAY1[@]}"
    echo "${MYARRAY2[@]}"
    
    exit 0

Just results in "line 10: MYARRAY1+=yyyy: command not found" rather than updating the array. This is actually for a more complex bash script I'm working on that has more arrays I want to update, so I'm hoping to avoid 'case' statements which would mean a big function body

You need bash 4.3 or later; the feature you want is called namerefs — Charles Duffy
– Charles Duffy, Commented Aug 3, 2021 at 14:51
By the way, it's better form to use POSIX function declarations -- updatearray() { with no function. See wiki.bash-hackers.org/scripting/obsolete — Charles Duffy
– Charles Duffy, Commented Aug 3, 2021 at 14:51

chepner · Accepted Answer · 2021-08-03 14:52:08Z

1

You can use namerefs, but take care:

updatearray () {
    declare -n a=$1
    a+=$2
}

answered Aug 3, 2021 at 14:52

chepner

538k77 gold badges594 silver badges746 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Is there in bash scripts a way of using variables to specify different bash arrays [duplicate]

1 Answer 1

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Linked

Related