3. How do I set environment variables in MSBuild file?

Question

3.  How do I set environment variables in MSBuild file?

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Answer 1

There is no direct way to set environment variables by default in an MSBuild file, but you can write a task to do this. The first thing you need is to create a new C# class library project, and write a task like this:

 

Code Sample:

using Microsoft.Build.Framework;

using Microsoft.Build.Utilities;

namespace MSBuildtasks

{

    public class SetEnvVar : Task

    {

        private string _variable;

        private string _value;

 

        [Required]

        public string Variable

        {

            get { return _variable; }

            set { _variable = value; }

        }

 

        [Required]

        public string Value

        {

            get { return _value; }

            set { _value = value; }

        }

 

        public override bool Execute()

        {

            Environment.SetEnvironmentVariable(_variable, _value);

            return true;

        }

    }

}

And then use it in the project file as follows:

 

Code Sample:

<UsingTask TaskName="MSBuildTasks.SetEnvVar"

         AssemblyFile="$(RootDir)Tools\Bin\MSBuildTasks.dll"/>

 

 <PropertyGroup>

  <TestPath>$(VS90COMNTOOLS)..\..</TestPath>

 </PropertyGroup>

 

 <Target Name="PrepareBuildEnvironment">

  <!-- To dump the env run msbuild with /p:DumpEnv=y switch -->

  <SetEnvVar Variable="TestPath" Value="$(TestPath)"/>

  <Message Condition="'$(DumpEnv)' != ''" Text="DumpEnv Requested:" />

  <Exec Condition="'$(DumpEnv)' != ''" Command="set" />

 </Target>

 

Relative threads:

http://social.msdn.microsoft.com/Forums/en-US/msbuild/thread/0fb8d97d-513e-4d37-8528-52973f65a034