Add WithExitCondition feature

CliWrap/Command.Execution.cs

@@ -219,11 +219,17 @@ private async Task<CommandResult> ExecuteAsync(
             .Register(process.Interrupt)
             .ToAsyncDisposable();
 
+        // Create token to cancel piping when process is finished and we don't need to finish piping
+        using var outputProcessingCts = new CancellationTokenSource();
+        using var pipeStdOutErrCts = CancellationTokenSource.CreateLinkedTokenSource(
+            forcefulCancellationToken,
+            outputProcessingCts.Token
+        );
         // Start piping streams in the background
         var pipingTask = Task.WhenAll(
             PipeStandardInputAsync(process, stdInCts.Token),
-            PipeStandardOutputAsync(process, forcefulCancellationToken),
-            PipeStandardErrorAsync(process, forcefulCancellationToken)
+            PipeStandardOutputAsync(process, pipeStdOutErrCts.Token),
+            PipeStandardErrorAsync(process, pipeStdOutErrCts.Token)
         );
 
         try
@@ -239,8 +245,34 @@ private async Task<CommandResult> ExecuteAsync(
             // If the pipe is still trying to transfer data, this will cause it to abort.
             await stdInCts.CancelAsync();
 
-            // Wait until piping is done and propagate exceptions
-            await pipingTask.ConfigureAwait(false);
+            if (CommandExitCondition == CommandExitCondition.PipesClosed)
+            {
+                try
+                {
+                    // Wait until piping is done and propagate exceptions
+                    await pipingTask.ConfigureAwait(false);
+                }
+                catch (OperationCanceledException)
+                {
+                    // throw original token if it was the source of cancel
+                    forcefulCancellationToken.ThrowIfCancellationRequested();
+                    throw;
+                }
+            }
+            else if (CommandExitCondition == CommandExitCondition.ProcessExited)
+            {
+                try
+                {
+                    // Cancel piping if we don't need to wait for it
+                    await outputProcessingCts.CancelAsync();
+                    await pipingTask.ConfigureAwait(false);
+                }
+                catch (OperationCanceledException) { }
+            }
+            else
+            {
+                throw new NotImplementedException($"{CommandExitCondition} is not implemented.");
+            }
         }
         // Swallow exceptions caused by internal and user-provided cancellations,
         // because we have a separate mechanism for handling them below.

CliWrap/Command.cs

@@ -19,7 +19,8 @@ public partial class Command(
     CommandResultValidation validation,
     PipeSource standardInputPipe,
     PipeTarget standardOutputPipe,
-    PipeTarget standardErrorPipe
+    PipeTarget standardErrorPipe,
+    CommandExitCondition commandExitCondition
 ) : ICommandConfiguration
 {
     /// <summary>
@@ -35,7 +36,8 @@ public Command(string targetFilePath)
             CommandResultValidation.ZeroExitCode,
             PipeSource.Null,
             PipeTarget.Null,
-            PipeTarget.Null
+            PipeTarget.Null,
+            CommandExitCondition.PipesClosed
         ) { }
 
     /// <inheritdoc />
@@ -50,6 +52,9 @@ public Command(string targetFilePath)
     /// <inheritdoc />
     public Credentials Credentials { get; } = credentials;
 
+    /// <inheritdoc />
+    public CommandExitCondition CommandExitCondition { get; } = commandExitCondition;
+
     /// <inheritdoc />
     public IReadOnlyDictionary<string, string?> EnvironmentVariables { get; } =
         environmentVariables;
@@ -80,7 +85,8 @@ public Command WithTargetFile(string targetFilePath) =>
             Validation,
             StandardInputPipe,
             StandardOutputPipe,
-            StandardErrorPipe
+            StandardErrorPipe,
+            CommandExitCondition
         );
 
     /// <summary>
@@ -101,7 +107,8 @@ public Command WithArguments(string arguments) =>
             Validation,
             StandardInputPipe,
             StandardOutputPipe,
-            StandardErrorPipe
+            StandardErrorPipe,
+            CommandExitCondition
         );
 
     /// <summary>
@@ -147,7 +154,8 @@ public Command WithWorkingDirectory(string workingDirPath) =>
             Validation,
             StandardInputPipe,
             StandardOutputPipe,
-            StandardErrorPipe
+            StandardErrorPipe,
+            CommandExitCondition
         );
 
     /// <summary>
@@ -164,7 +172,8 @@ public Command WithCredentials(Credentials credentials) =>
             Validation,
             StandardInputPipe,
             StandardOutputPipe,
-            StandardErrorPipe
+            StandardErrorPipe,
+            CommandExitCondition
         );
 
     /// <summary>
@@ -196,7 +205,8 @@ public Command WithEnvironmentVariables(
             Validation,
             StandardInputPipe,
             StandardOutputPipe,
-            StandardErrorPipe
+            StandardErrorPipe,
+            CommandExitCondition
         );
 
     /// <summary>
@@ -226,7 +236,26 @@ public Command WithValidation(CommandResultValidation validation) =>
             validation,
             StandardInputPipe,
             StandardOutputPipe,
-            StandardErrorPipe
+            StandardErrorPipe,
+            CommandExitCondition
+        );
+
+    /// <summary>
+    /// Creates a copy of this command, setting the exit condition to the specified value.
+    /// </summary>
+    [Pure]
+    public Command WithExitCondition(CommandExitCondition commandExitCondition) =>
+        new(
+            TargetFilePath,
+            Arguments,
+            WorkingDirPath,
+            Credentials,
+            EnvironmentVariables,
+            Validation,
+            StandardInputPipe,
+            StandardOutputPipe,
+            StandardErrorPipe,
+            commandExitCondition
         );
 
     /// <summary>
@@ -243,7 +272,8 @@ public Command WithStandardInputPipe(PipeSource source) =>
             Validation,
             source,
             StandardOutputPipe,
-            StandardErrorPipe
+            StandardErrorPipe,
+            CommandExitCondition
         );
 
     /// <summary>
@@ -260,7 +290,8 @@ public Command WithStandardOutputPipe(PipeTarget target) =>
             Validation,
             StandardInputPipe,
             target,
-            StandardErrorPipe
+            StandardErrorPipe,
+            CommandExitCondition
         );
 
     /// <summary>
@@ -277,7 +308,8 @@ public Command WithStandardErrorPipe(PipeTarget target) =>
             Validation,
             StandardInputPipe,
             StandardOutputPipe,
-            target
+            target,
+            CommandExitCondition
         );
 
     /// <inheritdoc />

CliWrap/CommandExitCondition.cs

@@ -0,0 +1,21 @@
+using System;
+
+namespace CliWrap;
+
+/// <summary>
+/// Strategy used for veryfing the end of command exectuion.
+/// </summary>
+[Flags]
+public enum CommandExitCondition
+{
+    /// <summary>
+    /// Command is finished when process is finished and all pipes are closed.
+    /// </summary>
+    PipesClosed = 0,
+
+    /// <summary>
+    /// Command is finished when the main process exits,
+    /// even if they are child processes still running, which are reusing the same output/error streams.
+    /// </summary>
+    ProcessExited = 1
+}