It's a very outdated version of the Bash shell on Mac OSX. maybe like GNU bash, version 3.2 I needed full features of a recent version of bash. There are many exceptions in an old version of bash like this. $ printf %d "'가'" -22 so just I did this to version up. $ brew install bash and I can get the below version $ bash --version GNU bash, 버전 5.1.4(1)-release (x86\_64-apple-darwin19.6.0) Copyrig..