From a5b573eaaa5b5e799dcd12d929a13d8d46a226a0 Mon Sep 17 00:00:00 2001
From: tonymanou <tonymanou@gmail.com>
Date: Sun, 15 Jan 2017 23:45:43 +0100
Subject: [PATCH] Read only the first line instead of loading the whole file

---
 .../main/java/com/topjohnwu/magisk/utils/Async.java   |  5 ++---
 .../main/java/com/topjohnwu/magisk/utils/Utils.java   | 11 +++++++++++
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/app/src/main/java/com/topjohnwu/magisk/utils/Async.java b/app/src/main/java/com/topjohnwu/magisk/utils/Async.java
index 5989c324e..f408e3dff 100644
--- a/app/src/main/java/com/topjohnwu/magisk/utils/Async.java
+++ b/app/src/main/java/com/topjohnwu/magisk/utils/Async.java
@@ -218,9 +218,8 @@ public class Async {
 
         protected boolean unzipAndCheck() {
             ZipUtils.unzip(mCachedFile, mCachedFile.getParentFile(), "META-INF/com/google/android");
-            List<String> ret;
-            ret = Utils.readFile(mCachedFile.getParent() + "/META-INF/com/google/android/updater-script");
-            return Utils.isValidShellResponse(ret) && ret.get(0).contains("#MAGISK");
+            String line = Utils.readFirstLine(mCachedFile.getParent() + "/META-INF/com/google/android/updater-script");
+            return line != null && line.contains("#MAGISK");
         }
 
         @Override
diff --git a/app/src/main/java/com/topjohnwu/magisk/utils/Utils.java b/app/src/main/java/com/topjohnwu/magisk/utils/Utils.java
index 36a90e652..08aeddd1a 100644
--- a/app/src/main/java/com/topjohnwu/magisk/utils/Utils.java
+++ b/app/src/main/java/com/topjohnwu/magisk/utils/Utils.java
@@ -75,6 +75,17 @@ public class Utils {
         return ret;
     }
 
+    public static String readFirstLine(String path) {
+        List<String> ret;
+        String command = "head -1 " + path;
+        if (Shell.rootAccess()) {
+            ret = Shell.su(command);
+        } else {
+            ret = Shell.sh(command);
+        }
+        return isValidShellResponse(ret) ? ret.get(0) : null;
+    }
+
     public static void dlAndReceive(Context context, DownloadReceiver receiver, String link, String filename) {
         if (isDownloading) {
             return;