From 1a53f8559663090f4d1fafbeac6ba828f2c05f39 Mon Sep 17 00:00:00 2001
From: Guillaume Nodet <gnodet@gmail.com>
Date: Fri, 5 Mar 2021 08:59:08 +0100
Subject: [PATCH] Support stream inheritance for the forked process, fixes #71

---
 .../java/org/codehaus/mojo/exec/ExecMojo.java | 12 +++-
 .../codehaus/mojo/exec/ExtendedExecutor.java  | 56 +++++++++++++++++++
 2 files changed, 67 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/org/codehaus/mojo/exec/ExtendedExecutor.java

diff --git a/src/main/java/org/codehaus/mojo/exec/ExecMojo.java b/src/main/java/org/codehaus/mojo/exec/ExecMojo.java
index c997889b..9fbd5a74 100644
--- a/src/main/java/org/codehaus/mojo/exec/ExecMojo.java
+++ b/src/main/java/org/codehaus/mojo/exec/ExecMojo.java
@@ -148,6 +148,16 @@ public class ExecMojo
     @Parameter( property = "exec.outputFile" )
     private File outputFile;
 
+    /**
+     * Program standard input, output and error streams will be inherited from the maven process.
+     * This allow tighter control of the streams and the console.
+     *
+     * @since 3.0.1
+     * @see ProcessBuilder#inheritIO()
+     */
+    @Parameter( property = "exec.inheritIo" )
+    private boolean inheritIo;
+
     /**
      * When enabled, program standard and error output will be redirected to the
      * Maven logger as <i>Info</i> and <i>Error</i> level logs, respectively. If not enabled the
@@ -384,7 +394,7 @@ else if ( !StringUtils.isEmpty( argsProp ) )
 
             commandLine.addArguments( args, false );
 
-            Executor exec = new DefaultExecutor();
+            Executor exec = new ExtendedExecutor( inheritIo );
             if ( this.timeout > 0 )
             {
                 exec.setWatchdog( new ExecuteWatchdog( this.timeout ) );
diff --git a/src/main/java/org/codehaus/mojo/exec/ExtendedExecutor.java b/src/main/java/org/codehaus/mojo/exec/ExtendedExecutor.java
new file mode 100644
index 00000000..8e7d0fb0
--- /dev/null
+++ b/src/main/java/org/codehaus/mojo/exec/ExtendedExecutor.java
@@ -0,0 +1,56 @@
+package org.codehaus.mojo.exec;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import org.apache.commons.exec.CommandLine;
+import org.apache.commons.exec.DefaultExecutor;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.Map;
+
+/**
+ * An executor which has the ability to use the {@link ProcessBuilder#inheritIO()} flag.
+ * 
+ * @author Guillaume Nodet (gnodet@gmail.com)
+ */
+public class ExtendedExecutor extends DefaultExecutor {
+
+    private final boolean inheritIo;
+
+    public ExtendedExecutor(boolean inheritIo) {
+        this.inheritIo = inheritIo;
+    }
+
+    @Override
+    protected Process launch(CommandLine command, Map<String, String> env, File dir) throws IOException {
+        if (dir != null && !dir.exists()) {
+            throw new IOException(dir + " doesn't exist.");
+        }
+        ProcessBuilder pb = new ProcessBuilder(command.toStrings());
+        pb.environment().putAll(env);
+        pb.directory(dir);
+        if (inheritIo) {
+            pb.inheritIO();
+        }
+        return pb.start();
+    }
+
+}