One construct I use in almost any script I write is : ${FOOBAR:=/etc/foobar.conf} to set a default value for a variable if it is unset or null. – Jens. Mar 10 ' ... ... <看更多>

Bash variables. A variable is a common concept shared by many programming languages. Variables are essentially a symbolic/temporary name for, or a reference to, ... ... <看更多>

So does Bash first run through the whole script to find variables? Nope. As you yourself discovered in your example, Bash scripts are ... ... <看更多>

And it's also important to have a consistent way in your scripts. Deprecated conventions. variable name started with an underscore ( _foo_bar ). ... <看更多>