Added: Add function to ProcessUtils to get app process name for a pid from ActivityManager

termux-shared/src/main/java/com/termux/shared/android/ProcessUtils.java

@@ -0,0 +1,58 @@
+package com.termux.shared.android;
+
+import android.app.ActivityManager;
+import android.content.Context;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import com.termux.shared.logger.Logger;
+
+import java.util.List;
+
+public class ProcessUtils {
+
+    public static final String LOG_TAG = "ProcessUtils";
+
+    /**
+     * Get the app process name for a pid with a call to {@link ActivityManager#getRunningAppProcesses()}.
+     *
+     * This will not return child process names. Android did not keep track of them before android 12
+     * phantom process addition, but there is no API via IActivityManager to get them.
+     *
+     * To get process name for pids of own app's child processes, check `get_process_name_from_cmdline()`
+     * in `local-socket.cpp`.
+     *
+     * https://cs.android.com/android/platform/superproject/+/android-12.0.0_r32:frameworks/base/core/java/android/app/ActivityManager.java;l=3362
+     * https://cs.android.com/android/platform/superproject/+/android-12.0.0_r32:frameworks/base/services/core/java/com/android/server/am/ActivityManagerService.java;l=8434
+     * https://cs.android.com/android/_/android/platform/frameworks/base/+/refs/tags/android-12.0.0_r32:services/core/java/com/android/server/am/PhantomProcessList.java
+     * https://cs.android.com/android/_/android/platform/frameworks/base/+/refs/tags/android-12.0.0_r32:services/core/java/com/android/server/am/PhantomProcessRecord.java
+     *
+     * @param context The {@link Context} for operations.
+     * @param pid The pid of the process.
+     * @return Returns the app process name if found, otherwise {@code null}.
+     */
+    @Nullable
+    public static String getAppProcessNameForPid(@NonNull Context context, int pid) {
+        if (pid < 0) return null;
+
+        ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
+        if (activityManager == null) return null;
+        try {
+            List<ActivityManager.RunningAppProcessInfo> runningApps = activityManager.getRunningAppProcesses();
+            if (runningApps == null) {
+                return null;
+            }
+            for (ActivityManager.RunningAppProcessInfo procInfo : runningApps) {
+                if (procInfo.pid == pid) {
+                    return procInfo.processName;
+                }
+            }
+        } catch (Exception e) {
+            Logger.logStackTraceWithMessage(LOG_TAG, "Failed to get app process name for pid " + pid, e);
+        }
+
+        return null;
+    }
+
+}