I am trying to set environment variables using project file (ex. .vcxproj)
I looked at property functions but it didn't seem to have such function.
I know there is a way to retrieve environment variable but couldn't find how to set it.
I feel like there should be way to set environment variables in project file.
The coded task can be put right at the project file since MSBuild v4.0. Like this:
<UsingTask
TaskName="SetEnvironmentVariableTask"
TaskFactory="CodeTaskFactory"
AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v$(MSBuildToolsVersion).dll">
<ParameterGroup>
<Name ParameterType="System.String" Required="true" />
<Value ParameterType="System.String" Required="true" />
</ParameterGroup>
<Task>
<Using Namespace="System" />
<Code Type="Fragment" Language="cs">
<![CDATA[
Environment.SetEnvironmentVariable(Name, Value);
]]>
</Code>
</Task>
</UsingTask>
Note that in MSBuild 14+, the AssemblyFile reference should be just:
AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.Core.dll"
The SetEnvironmentVariableTask can be then used from the target:
<Target Name="SampleTarget" BeforeTargets="Build">
<SetEnvironmentVariableTask Name="TEST_ENV_VAR" Value="$(MSBuildProjectName)" />
</Target>
That's much handier than authoring a separate .DLL for small MSBuild task(s).
In the more recent versions of MS Build (since 2016), you can simply do this:
<Target Name="MyEnvironmentVariables">
<Exec Command="A command that needs environment variables" EnvironmentVariables="HANDY_ENV_VAR_1=500;HANDY_ENV_VAR_2=A Useful Value" />
</Target>
Make sure to separate the variables with a semicolon. You don't need a trailing semicolon though.
...then you can use the standard MSBuild variables (aka properties) instead of trying to set an environment variable. You can set properties when running msbuild using the /property switch (aka /p switch) (more here), as shown in the example below, which sets the PublishProfile property to the value Debug and the VisualStudioVersion property to the value 15.0
msbuild Project.csproj /p:PublishProfile=Debug /p:VisualStudioVersion=15.0
Find a list of the standard MSBuild's variables/properties at this question
You could also define arbitrary properties in the csproj file itself, using the <PropertyGroup> element. More on that here
...well, it's not an out-of-box thing. You can write a custom task and then leverage it in the project file. Here's a link to an MSDN thread that outlines how to do this:
How to set envrionment variables in MSBuild file? This example creates a new C# class SetEnvVar which inherits from the Task class (Microsoft.Build.Utilities.Task), in the MSBuildTasks namespace.
//...
using Microsoft.Build.Framework;
using Microsoft.Build.Utilities;
namespace MSBuildTasks
{
public class SetEnvVar : Task
{
//...
public override bool Execute()
{
Environment.SetEnvironmentVariable(_variable, _value);
return true;
}
... and then the task is invoked by this part of the csproj file:
<UsingTask
TaskName="MSBuildTasks.SetEnvVar"
AssemblyFile="$(RootDir)Tools\Bin\MSBuildTasks.dll"/>
You might consider writing the environment variables to a text file (.cmd) as a sequence of SET XXX=$(XXX) lines. Then execute the .cmd in the command window.
e.g. Define an ItemGroup with all the SET commands, then use Task 'WriteLinesToFile' to write each item to a line in the .cmd text file.
<ItemGroup>
<BuildEnvItem Include="REM This file is auto generated. Do not edit" />
<BuildEnvItem Include="SET TEST_ENV_VAR=$(TEST_ENV_VAR)" />
<!-- add more as needed -->
<ItemGroup>
<Target Name="DefineBuildEnvironmentVariables">
<WriteLinesToFile File="Build_env.cmd" Lines="@(BuildEnvItem)" Overwrite="true" Encoding="Unicode"/>
</Target>
This is may be useful in the situation where there is an existing .cmd that is using msbuild. The initial .cmd uses msbuild to generate the Build_env.cmd, and then calls Build_env.cmd before proceeding.
