Check if variable is defined in PostBuildEvent

Question

I am using the following PostBuildEvent

<PostBuildEvent>
  IF DEFINED $(MyEnvVar) (
   mkdir "C:\tmp\"
   copy "$(TargetPath)" "$(MyEnvVar)/Addins/Software/bin/$(PlatformName)/$(TargetFileName)"
 )
</PostBuildEvent>

This event works if my MyEnvVar is defined. However, I get an error MSB3073 (exited with code 255) if the variable is not defined.

How can I define my PostBuild task to do some cmd operations, (create folders copy files as shown above), if the variable exists, or do nothing if it not?

Answer 1

You should not really be using post build events, at all, ever. Just create a target and have it run after the build target. In that target, have it copy the files you want. Something like this:

<Target Name="CopyMyStuff" AfterTargets="Build" Condition="exists('$(MyEnvVar)')" >
   <Copy SourceFiles="$(TargetPath)" DestinationFolder="$(MyEnvVar)\Addins\Software\bin\$(PlatformName)\" SkipUnchangedFiles="true" />
</Target>

I think this copy task will create the directory if it doesn't exist. A nice bonus.