properly nests. It should have been the way Bourne spelled
it from day one, but unfortunately isn't.
+ - If you want to find out if a command is available on the user's
+ $PATH, you should use 'type <command>', instead of 'which <command>'.
+ The output of 'which' is not machine parseable and its exit code
+ is not reliable across platforms.
+
- We use POSIX compliant parameter substitutions and avoid bashisms;
namely: