Re: Expanding variables in ReturnsZero function

[Mark . Burgess]

This would not work anyway as written.
Seems like some additional operators would be useful

IsDefined(var)
StrCmp(s1,s2)

etc. Will add to next release -- once my RSI allows me to work again.

M

On 25 Jul, paguerlais@airfrance.fr wrote:
> 
> Hi all,
> 
> I want to give a variable with a default value if it's not already defined.
> The only way I found to do that was to use a ReturnsZero function to test
> the current value of the variable, and to initialize it it's null :
> <cut>
> control:
>       host1::
>             my_var = ( value_for_host1 )
>       host2::
>             my_var = ( value_for_host2 )
> 
> groups:
>       my_var_is_already_valued = ( ReturnsZero(/bin/test -n "$(my_var)") )
> 
> control:
>       !my_var_is_already_valued::
>             my_var = ( some_default_value )
> </cut>
> 
> It doesn't work because cfengine doesn't expand variables used in a command
> for an internal function (I've spent some time reading functions.c,
> popen.c, misc.c and varstring.c). Is this done in purpose (and the next
> question is why), or was this feature simply forgot ? I'd like that feature
> not only for command arguments, but also for the command itself (you define
> a variable named TEST and valued with /bin/test, and you call ReturnsZero
> ($(TEST) ... ))
> 
> Next, is there a better way to test if a variable has a value ?
> 
> Thanks
> Patrice
> 
> 
> 
> 
> 
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