Restore terminal settings on SIGCONT, fixes #146

jline · Jul 21, 2015 · 3715461 · 3715461
1 parent f8d3b27
commit 3715461
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Showing 3 changed files with 52 additions and 18 deletions.
diff --git a/src/main/java/jline/UnixTerminal.java b/src/main/java/jline/UnixTerminal.java
@@ -11,6 +11,8 @@
 import jline.internal.Log;
 import jline.internal.TerminalLineSettings;
 
+import static jline.internal.Preconditions.checkNotNull;
+
 /**
  * Terminal that is used for unix platforms. Terminal initialization
  * is handled by issuing the <em>stty</em> command against the
@@ -33,15 +35,16 @@ public class UnixTerminal
     private String lnext;
 
     public UnixTerminal() throws Exception {
-    	this(TerminalLineSettings.TTY);
+    	this(TerminalLineSettings.DEFAULT_TTY);
     }
 
     public UnixTerminal(String ttyDevice) throws Exception {
         super(true);
+        checkNotNull(ttyDevice);
         settings = new TerminalLineSettings(ttyDevice);
     }
 
-    protected TerminalLineSettings getSettings() {
+    public TerminalLineSettings getSettings() {
         return settings;
     }
 

diff --git a/src/main/java/jline/console/ConsoleReader.java b/src/main/java/jline/console/ConsoleReader.java
@@ -26,6 +26,9 @@
 import java.io.OutputStreamWriter;
 import java.io.Reader;
 import java.io.Writer;
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
 import java.net.URL;
 import java.util.*;
 import java.util.List;
@@ -43,6 +46,7 @@
 import jline.internal.Log;
 import jline.internal.NonBlockingInputStream;
 import jline.internal.Nullable;
+import jline.internal.TerminalLineSettings;
 import jline.internal.Urls;
 import org.fusesource.jansi.AnsiOutputStream;
 
@@ -230,6 +234,42 @@ public ConsoleReader(final @Nullable String appName, final InputStream in, final
         this.inputrcUrl = getInputRc();
 
         consoleKeys = new ConsoleKeys(this.appName, inputrcUrl);
+
+        if (terminal instanceof UnixTerminal
+                && TerminalLineSettings.DEFAULT_TTY.equals(((UnixTerminal) terminal).getSettings().getTtyDevice())
+                && Configuration.getBoolean("jline.sigcont", false)) {
+            setupSigCont();
+        }
+    }
+
+    private void setupSigCont() {
+        // Check that sun.misc.SignalHandler and sun.misc.Signal exists
+        try {
+            Class<?> signalClass = Class.forName("sun.misc.Signal");
+            Class<?> signalHandlerClass = Class.forName("sun.misc.SignalHandler");
+            // Implement signal handler
+            Object signalHandler = Proxy.newProxyInstance(getClass().getClassLoader(),
+                    new Class<?>[]{signalHandlerClass}, new InvocationHandler() {
+                        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
+                            // only method we are proxying is handle()
+                            terminal.init();
+                            try {
+                                drawLine();
+                                flush();
+                            } catch (IOException e) {
+                                e.printStackTrace();
+                            }
+                            return null;
+                        }
+                    });
+            // Register the signal handler, this code is equivalent to:
+            // Signal.handle(new Signal("CONT"), signalHandler);
+            signalClass.getMethod("handle", signalClass, signalHandlerClass).invoke(null, signalClass.getConstructor(String.class).newInstance("CONT"), signalHandler);
+        } catch (ClassNotFoundException cnfe) {
+            // sun.misc Signal handler classes don't exist
+        } catch (Exception e) {
+            // Ignore this one too, if the above failed, the signal API is incompatible with what we're expecting
+        }
     }
 
     private URL getInputRc() throws IOException {

diff --git a/src/main/java/jline/internal/TerminalLineSettings.java b/src/main/java/jline/internal/TerminalLineSettings.java
@@ -41,8 +41,6 @@ public final class TerminalLineSettings
 
     private static final String UNDEFINED;
 
-    public static final String TTY;
-
     public static final String DEFAULT_TTY = "/dev/tty";
 
     private static final boolean SUPPORTS_REDIRECT;
@@ -62,18 +60,6 @@ public final class TerminalLineSettings
             supportsRedirect = false;
         }
         SUPPORTS_REDIRECT = supportsRedirect;
-
-        String tty;
-        if (supportsRedirect) {
-            try {
-                tty = waitAndCapture(inheritInput(new ProcessBuilder("tty")).start());
-            } catch (Throwable t) {
-                tty = DEFAULT_TTY;
-            }
-        } else {
-            tty = DEFAULT_TTY;
-        }
-        TTY = tty;
     }
 
     private String sttyCommand;
@@ -90,14 +76,15 @@ public final class TerminalLineSettings
     private boolean useRedirect;
 
     public TerminalLineSettings() throws IOException, InterruptedException {
-    	this(TTY);
+    	this(DEFAULT_TTY);
     }
 
     public TerminalLineSettings(String ttyDevice) throws IOException, InterruptedException {
+        checkNotNull(ttyDevice);
         this.sttyCommand = Configuration.getString(JLINE_STTY, DEFAULT_STTY);
         this.shCommand = Configuration.getString(JLINE_SH, DEFAULT_SH);
         this.ttyDevice = ttyDevice;
-        this.useRedirect = SUPPORTS_REDIRECT && TTY.equals(ttyDevice);
+        this.useRedirect = SUPPORTS_REDIRECT && DEFAULT_TTY.equals(ttyDevice);
         this.initialConfig = get("-g").trim();
         this.config = get("-a");
         this.configLastFetched = System.currentTimeMillis();
@@ -110,6 +97,10 @@ public TerminalLineSettings(String ttyDevice) throws IOException, InterruptedExc
         }
     }
 
+    public String getTtyDevice() {
+        return ttyDevice;
+    }
+
     public String getConfig() {
         return config;
     }