On 3/11/24 8:26 AM, Adrian Ho wrote:
Thanks much for all the insights, everyone! Indeed, the man page isn't clear on how to reason about `local -g`. I'm now left with the following understanding:1. There is *nothing local* about `local -g`; it operates entirely at the global level.
It exists to allow shell functions to create variables at the global scope with attributes that require the use of `declare', which is not possible without `-g'.
In particular, it does *not* create a local reference to a global var, which is the natural assumption given the typical behaviour of `declare/local`.
I would disagree that this assumption is `natural'.
2. Because of this, there is no way to *read* a global var if a calling scope declares a shadowing var, short of unsetting that shadow var.
This is how dynamic scoping works.
The `-g` option forces variables to be created or modified at the global scope, even when `declare` is executed in a shell function. to: The `-g` option forces variables to be created or modified at the global scope, even when `declare` is executed in a shell function, *and no references to these variables are created in that function's scope*.
I disagree that this particular addition is needed. I'd be happy to
entertain other suggestions about how to clarify the documentation.
Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU c...@case.edu http://tiswww.cwru.edu/~chet/
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