Variables in bash
If you want to understand a programming language, start with its variables. I’m learning Bash, so let’s see how Bash variables work.
Bash variables have names, like
They’re made of ASCII letters, digits, and
_ (and the first char must not be a digit).
(Except, possibly, for some “special” variables, like
1, the first argument.)
To assign to a variable, we write assignment statements like:
a=3 # variable `a` gets the value "3" b1= # variable `b1` gets the value "" FOO= 45 # variable `FOO` gets the value " 45" echo = baz # not an assignment! Instead, calls `echo` with two arguments
Notice that they’re all assigned strings,
and that whitespace around the
= is significant.
All bash variables are strings.
Yes, bash can treat these variables as integers sometimes,
but in “storage”, they are strings.
Bash variables are dynamically scoped. To illustrate:
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