This article is not specifically about Bash, but about the shell command language sh. The POSIX Shell is a standardized subset of Bash which has even better portability. I would recommend learning and using sh unless you really need Bash.
Your script will use sh if it starts with #!/bin/sh (instead of #!/bin/bash).
I can also recommend ShellCheck which is a shell script analysis tool (implemented in Haskell) which can find errors and potential problems in your scripts. On a Debian system, installing ShellScheck is as simple as `sudo apt install shellcheck'.
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V...
Your script will use sh if it starts with #!/bin/sh (instead of #!/bin/bash).
I can also recommend ShellCheck which is a shell script analysis tool (implemented in Haskell) which can find errors and potential problems in your scripts. On a Debian system, installing ShellScheck is as simple as `sudo apt install shellcheck'.