local variables in bash
jon at endpoint.com
Thu Feb 12 19:10:30 MST 2009
On Thu, 12 Feb 2009, Shane Hathaway wrote:
>> This is a problem with bash - that is if one function calls another the
>> value of the local variables are seen.
> It's a surprise, but it follows the bash documentation.
> $ help local
> local: local name[=value] ...
> Create a local variable called NAME, and give it VALUE. LOCAL
> can only be used within a function; it makes the variable NAME
> have a visible scope restricted to that function and its children.
> The "... and its children" specification is different from most
> programming languages that I'm familiar with. I guess bash searches the
> call stack for variables, rather than use scoping rules like most
> languages. Another reason not to write anything complex in bash. :-)
This is just like Perl's "local", which provides temporary scoping to a
global variable. It's not much used, with "my" being more what people are
usually looking for. See man perlsub for details, section "Temporary
Values via local()".
I wouldn't be surprised if bash borrowed the behavior & the name from
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