On 4/12/2012 2:16 PM, dethrophes wrote:
Am 12.04.2012 14:27, schrieb Chet Ramey:
On 4/11/12 4:12 PM, dethrophes wrote:
I've also noticed weird behavior with "declare -gr" the r sometimes
seems
to override the g, but not specific to functions It seems to be
specific
either to the source file or to the compound statement. I haven't
been able
to figure out exactly whats going on there. I haven't been able to
reproduce it in a simple example. this is most readily noticeable
with set
-o nounset
An example would help. The above is supposed to create a global
readonly
variable. I suspect that you see the `global' as being `overridden'
because it's being created in a subshell environment.
Chet
It took me a second to reproduce it, but here it is:
----------------------
#! /bin/bash
A()
{
typeset v1=Hello
B
echo "IN B:$v1"
}
B()
{
typeset -r v1=Goodbye
:
}
typeset -r v1=abc
A
echo "v1:$v1"
--------------------------
This is 4.0.35(1).
The v1 that's set to abc is the global one.
A defines a local copy that's not readonly and B defines one that is.
When I run it I get:
950 > ./foo.sh
./foo.sh: line 5: typeset: v1: readonly variable
./foo.sh: line 13: typeset: v1: readonly variable
IN B:abc
v1:abc
This means that the typeset failed is both A and B and the references
in the routines fell back to the global instance of v1.
Does this help?
I only see the problem in large complex cases, I've tried to reproduce a
simple example a couple of times but without success.
no its not a subshell problem, I avoid subshells as much as possible.
also when I expereimented with the problem a couple of times I
discovered the
following-
declare -g works
declare -gr doesn't work
my current workaround is I've just stopped using the readonly
attribute which
works. or just stopped using declare altogether.
or do something like this
var=x
typeset -r var
I've also seen some strange behavior with
declare in a conditional sourced global context. it only seems to
happen when
the code size is 10000s+ lines long.
I think this is exasperated by the fact that i source my files inside
conditional statements. the result is that I now even in a global
context set
the global flag.
any ideas what could be causing it would help me try to figure out
how to test
for it.
Sorry about the weak description but I've been working around it now for
months waiting for it to make sense and I'm no closer to figuring out
whats
going on.
the problem is so erratic it has to be some sort of partial lost
context or
something.
can you give me any tips on how to debug it if I can reproduce it
again? is
their an easy way to track the validity of a variable?