bash: IFSと配列の[*]の挙動

arr_ifs.md

$ bash --version
GNU bash, version 4.3.46(1)-release (x86_64-pc-linux-gnu)
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>

This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

$ arr=("aa" "bb" "cc")
$ export IFS=@

クオートで囲まないとIFSは使われない

$ echo ${arr[*]}
aa bb cc

$ echo "${arr[*]}"
aa@bb@cc

exportしないと変わらない

$ IFS="-" echo "${arr[*]}"
aa@bb@cc

$ export IFS="-"; echo "${arr[*]}"
aa-bb-cc