How to get all the keys in an associative array in Bash?
Posted on In TutorialHow to get all the keys of an associative array in Bash?
There are at least 2 ways to get the keys from an associative array of Bash. Let’s start with an example associative array:
$ declare -A aa
$ aa["foo"]=bar
$ aa["a b"]=c
We can use the @
special index to get all the keys and store them in an array:
$ aakeys=("${!aa[@]}")
The array content is all the keys (note the key “a b” has a space within itself):
$ echo ${aakeys[*]}
foo a b
Another more convenient way to operate on the keys from an associative array is to loop the keys as follows:
$ for key in "${!aa[@]}"; do echo $key; done
foo
a b
The spaces are well handled in the for loop.