From 14cfd6abeba3a6b488ab72c648e80d4f12620eb8 Mon Sep 17 00:00:00 2001
From: huanghongxun <i@huangyuhui.net>
Date: Wed, 8 Apr 2020 21:18:25 +0800
Subject: [PATCH] add: support variables in prelaunch command which is
 supported by MultiMC. Closes #698

---
 .../org/jackhuang/hmcl/launch/DefaultLauncher.java  | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/launch/DefaultLauncher.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/launch/DefaultLauncher.java
index 9924d5e2e..f4c52d83d 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/launch/DefaultLauncher.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/launch/DefaultLauncher.java
@@ -283,9 +283,18 @@ public class DefaultLauncher extends Launcher {
 
         File runDirectory = repository.getRunDirectory(version.getId());
 
-        if (StringUtils.isNotBlank(options.getPreLaunchCommand()))
-            new ProcessBuilder(options.getPreLaunchCommand())
+        if (StringUtils.isNotBlank(options.getPreLaunchCommand())) {
+            String versionName = Optional.ofNullable(options.getVersionName()).orElse(version.getId());
+            String preLaunchCommand = options.getPreLaunchCommand()
+                    .replace("$INST_NAME", versionName)
+                    .replace("$INST_ID", versionName)
+                    .replace("$INST_DIR", repository.getVersionRoot(version.getId()).getAbsolutePath())
+                    .replace("$INST_MC_DIR", repository.getRunDirectory(version.getId()).getAbsolutePath())
+                    .replace("$INST_JAVA", options.getJava().getBinary().toString());
+
+            new ProcessBuilder(preLaunchCommand)
                     .directory(runDirectory).start().waitFor();
+        }
 
         Process process;
         try {