Variables TCL regsub到变量？

我正在设置宏，设置，然后说。在程序中定义

proc Set {key value args} {
    set ::$key $value
            set "::key2" "$key"
}

proc Say {key} {
puts $key
}

proc Say2 {key} {
set key3 [regsub "\%" $key "\$"]
puts $key3
eval puts $key3
}

这允许我执行以下操作：

Set "test" "this should display this test text"
Say $key2 ;#should display the key "test" which is what we just set
Say $test ;#presents the value of the key test

输出

% Set "test" "this should display this test text"
test
% Say $key2 ;#should display the key "test" which is what we just set
test
% Say $test ;#presents the value of the key test
this should display this test text

% Set "mouse" "squeak" ;#set key mouse with value string of "squeak"
mouse
% Say $mouse ;#displays the value as set above correctly
squeak
% Say2 %mouse ;#start using our own characters to represent variables
$mouse
can't read "mouse": no such variable

现在让我们假设我想重新分配变量$to%

Set "mouse" "squeak" ;#set key mouse with value string of "squeak"
Say $mouse ;#displays the value as set above correctly
Say2 %mouse ;#start using our own characters to represent variables - switch the % for a $ and then output

但是当我使用eval时

 can't read "mouse": no such variable

输出

% Set "test" "this should display this test text"
test
% Say $key2 ;#should display the key "test" which is what we just set
test
% Say $test ;#presents the value of the key test
this should display this test text

% Set "mouse" "squeak" ;#set key mouse with value string of "squeak"
mouse
% Say $mouse ;#displays the value as set above correctly
squeak
% Say2 %mouse ;#start using our own characters to represent variables
$mouse
can't read "mouse": no such variable

我觉得这很奇怪，因为我们在上面设置了它，我们可以使用标准$调用值，我可以证明Say2中的regsub工作正常，它应该用$替换%

%鼠标变为$mouse，这是一个有效变量。 Eval$鼠标输出，不带此类变量

我错过什么了吗

---

谢谢

问题在于

程序

：

proc Say2 {key} {
    set key3 [regsub {%} $key {$}]
    puts $key3
    eval puts $key3 ;# here
}

$mouse

在此

proc

中不存在。它不是作为参数传递的，也不是用

set

创建的。但是，它存在于全局命名空间中。在这种情况下，一种方法是使用

uplevel

：

proc Say2 {key} {
    set key3 [regsub {%} $key {$}]
    puts $key3
    uplevel puts $key3
}

我经常使用的另一个选项是

upvar

，将变量放入其中（尽管在本例中，我们不再需要

$

）：

---

PS：我还删除了一些反斜杠，因为在这种情况下它们并不真正需要。

现在我了解了upvar的用法。太好了！