It is always helpful in recording if any bash behavior changes when it is not running in POSIX mode. This is most common in Debian and Ubuntu, where ash is /bi

It is always helpful in recording if any bash behavior changes when it is not running in POSIX mode. This is most common in Debian and Ubuntu, where ash is /bin/sh, and /bin/bash does not run in POSIX mode by default. Some behavior of legacy bash of the '80s, prior to POSIX.2, can be surprising. https://w3.pppl.gov/info/bash/Bash_POSIX_Mode.html https://w3.pppl.gov/info/bash/Bash_POSIX_Mode.html