NAnt: cannot resolve to boolean value

<if test="${deployErrors} &gt; 0">
   <fail message="MSDeploy failed" />
</if>

${deployErrors} is populated from a regex capture group and either has a numeric value or empty string. How can I check if this is greater than 0 in a NAnt if block? Here's the error I'm getting if deploy errors contains '1'

'1 > 0' is not a valid value for attribute 'test' of . Cannot resolve '1 > 0' to boolean value. String was not reco开发者_如何学编程gnized as a valid Boolean.

I've not tried it, but I think you need the whole of your expression within the curly braces:

<if test="${deployErrors > 0}">

See also the second example in the documentation page.

Update from OP:

This worked:

<if test="${deployErrors != ''}">

If you need to do something with the actual numeric value then you could do something like this:

<if test="${int::parse('0' + deployErrors) > 10}">

Similar to Trystan's answer - to parse a string to a bool, for a string e.g. true, false

<if test="${bool::parse(isEnabled)}">

From http://nant.sourceforge.net/release/0.85/help/functions/bool.parse.html