[CMake] if(string MATCHES regex) question

[Eric Noulard]

2009/7/1 Marcel Loose <loose at astron.nl>:
> Hi all,
>
> In a number of standard CMake modules I encountered the following line:
>
>  IF("${VARIABLE}" MATCHES "^${VARIABLE}$")
>
> Can anyone explain the rationale of this conditional to me.

The rational no but ....

> To my cluttered mind this seems to be an "always-true" condition.

this is definitely not always true.
The variable your are testing may contain "un-evaluated" var
or some special regex character( *, ?, ...)

See attached example, you may test it with
$ cmake -P matches.cmake
MATCHES -- MYVAR = A good var
Look that one = double-dollar = blah / single-dollar = MYVAR2
NO MATCHES ** MYVAR = MYVAR2
$

However I have no such usage currently :-)

-- 
Erk
Membre de l'April - « promouvoir et défendre le logiciel libre » -
http://www.april.org
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