Start work on background jobs

app/src/main/java/com/termux/app/BackgroundJob.java

@@ -7,55 +7,71 @@ import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.lang.reflect.Field;
 import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
 
 /**
  * A background job launched by Termux.
  */
 public final class BackgroundJob {
 
-    private static final String LOG_TAG = "termux-background";
+    private static final String LOG_TAG = "termux-job";
 
     final Process mProcess;
 
-    public BackgroundJob(File cwd, File fileToExecute, String[] args) throws IOException {
+    public BackgroundJob(String cwd, String fileToExecute, final String[] args) {
-        String[] env = buildEnvironment(false, cwd.getAbsolutePath());
+        String[] env = buildEnvironment(false, cwd);
+        if (cwd == null) cwd = TermuxService.HOME_PATH;
 
-        String[] progArray = new String[args.length + 1];
+        String[] modifiedArgs;
+        if (args == null) {
+            modifiedArgs = new String[]{fileToExecute};
+        } else {
+            modifiedArgs = new String[args.length + 1];
+            modifiedArgs[0] = fileToExecute;
+            System.arraycopy(args, 0, modifiedArgs, 1, args.length);
+        }
+        final String[] progArray = modifiedArgs;
 
-        mProcess = Runtime.getRuntime().exec(progArray, env, cwd);
+        final String processDescription = Arrays.toString(progArray);
-
+
-        new Thread() {
+        Process process;
-            @Override
+        try {
-            public void run() {
+            process = Runtime.getRuntime().exec(progArray, env, new File(cwd));
-                while (true) {
+        } catch (IOException e) {
-                    try {
+            mProcess = null;
-                        int exitCode = mProcess.waitFor();
+            // TODO: Visible error message?
-                        if (exitCode == 0) {
+            Log.e(LOG_TAG, "Failed running background job: " + processDescription, e);
-                            Log.i(LOG_TAG, "exited normally");
+            return;
-                            return;
+        }
-                        } else {
+        mProcess = process;
-                            Log.i(LOG_TAG, "exited with exit code: " + exitCode);
+        final int pid = getPid(mProcess);
-                        }
-                    } catch (InterruptedException e) {
-                        // Ignore.
-                    }
-                }
-            }
-        }.start();
 
         new Thread() {
             @Override
             public void run() {
+                Log.i(LOG_TAG, "[" + pid + "] starting: " + processDescription);
                 InputStream stdout = mProcess.getInputStream();
                 BufferedReader reader = new BufferedReader(new InputStreamReader(stdout, StandardCharsets.UTF_8));
                 String line;
                 try {
                     // FIXME: Long lines.
                     while ((line = reader.readLine()) != null) {
-                        Log.i(LOG_TAG, line);
+                        Log.i(LOG_TAG, "[" + pid + "] stdout: " + line);
                     }
                 } catch (IOException e) {
+                    Log.e(LOG_TAG, "Error reading output", e);
+                }
+
+                try {
+                    int exitCode = mProcess.waitFor();
+                    if (exitCode == 0) {
+                        Log.i(LOG_TAG, "[" + pid + "] exited normally");
+                    } else {
+                        Log.w(LOG_TAG, "[" + pid + "] exited with code: " + exitCode);
+                    }
+                } catch (InterruptedException e) {
                     // Ignore.
                 }
             }
@@ -71,7 +87,7 @@ public final class BackgroundJob {
                 try {
                     // FIXME: Long lines.
                     while ((line = reader.readLine()) != null) {
-                        Log.e(LOG_TAG, line);
+                        Log.i(LOG_TAG, "[" + pid + "] stderr: " + line);
                     }
                 } catch (IOException e) {
                     // Ignore.
@@ -80,7 +96,7 @@ public final class BackgroundJob {
         };
     }
 
-    public String[] buildEnvironment(boolean failSafe, String cwd) {
+    public static String[] buildEnvironment(boolean failSafe, String cwd) {
         new File(TermuxService.HOME_PATH).mkdirs();
 
         if (cwd == null) cwd = TermuxService.HOME_PATH;
@@ -109,4 +125,18 @@ public final class BackgroundJob {
         }
     }
 
+    public static int getPid(Process p) {
+        int pid = -1;
+
+        try {
+            Field f = p.getClass().getDeclaredField("pid");
+            f.setAccessible(true);
+            pid = f.getInt(p);
+            f.setAccessible(false);
+        } catch (Throwable e) {
+            pid = -1;
+        }
+        return pid;
+    }
+
 }

app/src/main/java/com/termux/app/TermuxService.java

@@ -119,21 +119,26 @@ public final class TermuxService extends Service implements SessionChangedCallba
             String executablePath = (executableUri == null ? null : executableUri.getPath());
             String[] arguments = (executableUri == null ? null : intent.getStringArrayExtra(EXTRA_ARGUMENTS));
             String cwd = intent.getStringExtra(EXTRA_CURRENT_WORKING_DIRECTORY);
-            TerminalSession newSession = createTermSession(executablePath, arguments, cwd, false);
 
-            // Transform executable path to session name, e.g. "/bin/do-something.sh" => "do something.sh".
+            if (intent.getBooleanExtra("com.termux.execute.background", false)) {
-            if (executablePath != null) {
+                new BackgroundJob(cwd, executablePath, arguments);
-                int lastSlash = executablePath.lastIndexOf('/');
+            } else {
-                String name = (lastSlash == -1) ? executablePath : executablePath.substring(lastSlash + 1);
+                TerminalSession newSession = createTermSession(executablePath, arguments, cwd, false);
-                name = name.replace('-', ' ');
+
-                newSession.mSessionName = name;
+                // Transform executable path to session name, e.g. "/bin/do-something.sh" => "do something.sh".
+                if (executablePath != null) {
+                    int lastSlash = executablePath.lastIndexOf('/');
+                    String name = (lastSlash == -1) ? executablePath : executablePath.substring(lastSlash + 1);
+                    name = name.replace('-', ' ');
+                    newSession.mSessionName = name;
+                }
+
+                // Make the newly created session the current one to be displayed:
+                TermuxPreferences.storeCurrentSession(this, newSession);
+
+                // Launch the main Termux app, which will now show to current session:
+                startActivity(new Intent(this, TermuxActivity.class).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK));
             }
-
-            // Make the newly created session the current one to be displayed:
-            TermuxPreferences.storeCurrentSession(this, newSession);
-
-            // Launch the main Termux app, which will now show to current session:
-            startActivity(new Intent(this, TermuxActivity.class).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK));
         } else if (action != null) {
             Log.e(EmulatorDebug.LOG_TAG, "Unknown TermuxService action: '" + action + "'");
         }
@@ -236,28 +241,7 @@ public final class TermuxService extends Service implements SessionChangedCallba
 
         if (cwd == null) cwd = HOME_PATH;
 
-        final String termEnv = "TERM=xterm-256color";
+        String[] env = BackgroundJob.buildEnvironment(failSafe, cwd);
-        final String homeEnv = "HOME=" + HOME_PATH;
-        final String prefixEnv = "PREFIX=" + PREFIX_PATH;
-        final String androidRootEnv = "ANDROID_ROOT=" + System.getenv("ANDROID_ROOT");
-        final String androidDataEnv = "ANDROID_DATA=" + System.getenv("ANDROID_DATA");
-        // EXTERNAL_STORAGE is needed for /system/bin/am to work on at least
-        // Samsung S7 - see https://plus.google.com/110070148244138185604/posts/gp8Lk3aCGp3.
-        final String externalStorageEnv = "EXTERNAL_STORAGE=" + System.getenv("EXTERNAL_STORAGE");
-        String[] env;
-        if (failSafe) {
-            // Keep the default path so that system binaries can be used in the failsafe session.
-            final String pathEnv = "PATH=" + System.getenv("PATH");
-            env = new String[]{termEnv, homeEnv, prefixEnv, androidRootEnv, androidDataEnv, pathEnv, externalStorageEnv};
-        } else {
-            final String ps1Env = "PS1=$ ";
-            final String ldEnv = "LD_LIBRARY_PATH=" + PREFIX_PATH + "/lib";
-            final String langEnv = "LANG=en_US.UTF-8";
-            final String pathEnv = "PATH=" + PREFIX_PATH + "/bin:" + PREFIX_PATH + "/bin/applets";
-            final String pwdEnv = "PWD=" + cwd;
-
-            env = new String[]{termEnv, homeEnv, prefixEnv, ps1Env, ldEnv, langEnv, pathEnv, pwdEnv, androidRootEnv, androidDataEnv, externalStorageEnv};
-        }
 
         String shellName;
         if (executablePath == null) {