Environment.GetCommandLineArgs()[0] preserves the apphost invocation name

When you launch an app through its apphost, Environment.GetCommandLineArgs() now preserves the invocation name, including a relative path or symlink name. The behavior for dotnet <application.dll> is unchanged.

Version introduced

.NET 11 Preview 7

Previous behavior

Previously, when you launched an app through its apphost, Environment.GetCommandLineArgs()[0] returned the managed assembly path or the resolved executable path, rather than the invocation name.

New behavior

Starting in .NET 11, when you launch an app through its apphost, Environment.GetCommandLineArgs()[0] preserves the invocation name, including relative paths and symlink names. For example, if special_myapp is a symlink to myapp, and you run ./special_myapp, the value is ./special_myapp.

When you launch an app with dotnet <application.dll>, the behavior is unchanged.

Type of breaking change

This change is a behavioral change.

Reason for change

To align .NET with native process behavior, the runtime now preserves the value of argv[0] supplied at launch. This behavior also lets an app distinguish which symlink name launched it.

Recommended action

To get the executable path, use Environment.ProcessPath. To get the managed entry assembly location, use Assembly.GetEntryAssembly()?.Location (see Assembly.GetEntryAssembly() and Assembly.Location). The location is an empty string for bundled assemblies in single-file apps. Keep using Environment.GetCommandLineArgs()[0] when you need the invocation name.

Affected APIs

• System.Environment.GetCommandLineArgs()