Please limit your shell scripting to POSIX sh for the sake of broad compatibility with current and future operating systems. There's a quick reference here: ht

Please limit your shell scripting to POSIX sh for the sake of broad compatibility with current and future operating systems. There's a quick reference here: https://shellhaters.org/ https://shellhaters.org/ If you find yourself frustrated by the lack of bash extensions, your program is probably complex enough that you probably shouldn't be writing a shell script.