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Re: param expansion with single-character special vars in the environmen
From: |
Piotr Grzybowski |
Subject: |
Re: param expansion with single-character special vars in the environment |
Date: |
Wed, 27 Apr 2016 23:22:46 +0200 |
On 27 Apr 2016, at 21:49, Eduardo A. Bustamante López wrote:
>
> Actually, this seems to be a special case, just because '5' is an invalid
> variable name. But the problem still exists:
>
> | dualbus@hp ...src/gnu/bash % ./bash -c 'declare -r RO=x; r=$RO; declare -n
> r; x=y; declare -n RO; RO=z; declare -p RO; echo "$RO"'
> | declare -nr RO="x"
> | z
ok lets take a look:
> declare -r RO=x; r=$RO;
a read only variable RO and variable r with value "x"
> declare -n r;
from now on every assignment to r assigns to variable of name x
> x=y;
variavle of name x has value y
> declare -n RO;
here you make RO a nameref, from now on assignments to RO are not assignments
to readonly variable RO but to variable of name "$RO" in this case variable x
> RO=z;
assigment to variable x via a nameref called RO
> declare -p RO; echo "$RO"
print the value of the variable referenced to by $RO, in that case x.
No assignment to readonly variables whatsoever.
if you want to make a nameref that has the same name as the readonly variable,
feel free.
The only bug I see, is the apparent impossibility of removing the nameref from
readonly variable, I assure you, if you could remove the nameref from RO you
would recover "x" because it is still there in the entry of variables table, as
seen by declare -p.
I do not see other bug here.
What do you think?
cheers,
pg
- Re: param expansion with single-character special vars in the environment, (continued)
- Re: param expansion with single-character special vars in the environment, Grisha Levit, 2016/04/25
- Re: param expansion with single-character special vars in the environment, Piotr Grzybowski, 2016/04/27
- Re: param expansion with single-character special vars in the environment, Grisha Levit, 2016/04/27
- Re: param expansion with single-character special vars in the environment, Piotr Grzybowski, 2016/04/27
- Re: param expansion with single-character special vars in the environment, Eduardo A . Bustamante López, 2016/04/27
- Re: param expansion with single-character special vars in the environment, Eduardo A . Bustamante López, 2016/04/27
- Re: param expansion with single-character special vars in the environment, Piotr Grzybowski, 2016/04/27
- Re: param expansion with single-character special vars in the environment, Eduardo A . Bustamante López, 2016/04/27
- Re: param expansion with single-character special vars in the environment, Eduardo A . Bustamante López, 2016/04/27
- Re: param expansion with single-character special vars in the environment, Grisha Levit, 2016/04/27
- Re: param expansion with single-character special vars in the environment,
Piotr Grzybowski <=
- Re: param expansion with single-character special vars in the environment, Piotr Grzybowski, 2016/04/27
- Re: param expansion with single-character special vars in the environment, Grisha Levit, 2016/04/27
- Re: param expansion with single-character special vars in the environment, Piotr Grzybowski, 2016/04/27
Re: param expansion with single-character special vars in the environment, Piotr Grzybowski, 2016/04/27
- Re: param expansion with single-character special vars in the environment, Piotr Grzybowski, 2016/04/27
- Re: param expansion with single-character special vars in the environment, Grisha Levit, 2016/04/27
- Re: param expansion with single-character special vars in the environment, Piotr Grzybowski, 2016/04/28
- Re: param expansion with single-character special vars in the environment, Piotr Grzybowski, 2016/04/28
- Re: param expansion with single-character special vars in the environment, Grisha Levit, 2016/04/28
Re: param expansion with single-character special vars in the environment, Eduardo A . Bustamante López, 2016/04/27