Added Terminal.getTerminalSize().

src/main/cpp/posixFunctions.c

@@ -3,6 +3,7 @@
 #include <sys/stat.h>
 #include <errno.h>
 #include <unistd.h>
+#include <sys/ioctl.h>
 
 void markFailed(JNIEnv *env, jobject result) {
     jclass destClass = env->GetObjectClass(result);
@@ -48,3 +49,18 @@ Java_net_rubygrapefruit_platform_internal_PosixTerminalFunctions_isatty(JNIEnv *
         return JNI_FALSE;
     }
 }
+
+JNIEXPORT void JNICALL
+Java_net_rubygrapefruit_platform_internal_PosixTerminalFunctions_getTerminalSize(JNIEnv *env, jclass target, jint output, jobject dimension, jobject result) {
+    struct winsize screen_size;
+    int retval = ioctl(output+1, TIOCGWINSZ, &screen_size);
+    if (retval != 0) {
+        markFailed(env, result);
+        return;
+    }
+    jclass dimensionClass = env->GetObjectClass(dimension);
+    jfieldID widthField = env->GetFieldID(dimensionClass, "cols", "I");
+    env->SetIntField(dimension, widthField, screen_size.ws_col);
+    jfieldID heightField = env->GetFieldID(dimensionClass, "rows", "I");
+    env->SetIntField(dimension, heightField, screen_size.ws_row);
+}

src/main/java/net/rubygrapefruit/platform/Main.java

@@ -1,11 +1,21 @@
 package net.rubygrapefruit.platform;
 
+import java.awt.*;
+
 public class Main {
     public static void main(String[] args) {
         Process process = Platform.get(Process.class);
         System.out.println("* PID: " + process.getPid());
+
         Terminal terminal = Platform.get(Terminal.class);
-        System.out.println("* stdout: " + (terminal.isTerminal(Terminal.Output.Stdout) ? "terminal" : "not a terminal"));
+
-        System.out.println("* stderr: " + (terminal.isTerminal(Terminal.Output.Stderr) ? "terminal" : "not a terminal"));
+        boolean stdoutIsTerminal = terminal.isTerminal(Terminal.Output.Stdout);
+        boolean stderrIsTerminal = terminal.isTerminal(Terminal.Output.Stderr);
+        System.out.println("* stdout: " + (stdoutIsTerminal ? "terminal" : "not a terminal"));
+        System.out.println("* stderr: " + (stderrIsTerminal ? "terminal" : "not a terminal"));
+        if (stdoutIsTerminal) {
+            TerminalSize terminalSize = terminal.getTerminalSize(Terminal.Output.Stdout);
+            System.out.println("* terminal size: " + terminalSize.getCols() + " cols x " + terminalSize.getRows() + " rows");
+        }
     }
 }

src/main/java/net/rubygrapefruit/platform/Platform.java

@@ -31,12 +31,7 @@ public class Platform {
             return type.cast(new DefaultProcess());
         }
         if (type.equals(Terminal.class)) {
-            return type.cast(new Terminal(){
+            return type.cast(new DefaultTerminal());
-                @Override
-                public boolean isTerminal(Output output) {
-                    return PosixTerminalFunctions.isatty(output.ordinal());
-                }
-            });
         }
         throw new UnsupportedOperationException(String.format("Cannot load unknown native integration %s.",
                 type.getName()));
@@ -70,4 +65,22 @@ public class Platform {
             return PosixProcessFunctions.getPid();
         }
     }
+
+    private static class DefaultTerminal implements Terminal {
+        @Override
+        public boolean isTerminal(Output output) {
+            return PosixTerminalFunctions.isatty(output.ordinal());
+        }
+
+        @Override
+        public TerminalSize getTerminalSize(Output output) {
+            MutableTerminalSize terminalSize = new MutableTerminalSize();
+            FunctionResult result = new FunctionResult();
+            PosixTerminalFunctions.getTerminalSize(output.ordinal(), terminalSize, result);
+            if (result.isFailed()) {
+                throw new NativeException(String.format("Could not get terminal size. Errno is %d.", result.getErrno()));
+            }
+            return terminalSize;
+        }
+    }
 }

src/main/java/net/rubygrapefruit/platform/Terminal.java

@@ -4,4 +4,6 @@ public interface Terminal extends NativeIntegration {
     enum Output {Stdout, Stderr}
 
     boolean isTerminal(Output output);
+
+    TerminalSize getTerminalSize(Output output);
 }

src/main/java/net/rubygrapefruit/platform/TerminalSize.java

@@ -0,0 +1,7 @@
+package net.rubygrapefruit.platform;
+
+public interface TerminalSize {
+    public int getCols();
+
+    public int getRows();
+}

src/main/java/net/rubygrapefruit/platform/internal/MutableTerminalSize.java

@@ -0,0 +1,16 @@
+package net.rubygrapefruit.platform.internal;
+
+import net.rubygrapefruit.platform.TerminalSize;
+
+public class MutableTerminalSize implements TerminalSize {
+    int rows;
+    int cols;
+
+    public int getCols() {
+        return cols;
+    }
+
+    public int getRows() {
+        return rows;
+    }
+}

src/main/java/net/rubygrapefruit/platform/internal/PosixTerminalFunctions.java

@@ -1,5 +1,7 @@
 package net.rubygrapefruit.platform.internal;
 
 public class PosixTerminalFunctions {
-    public static native boolean isatty(int fildes);
+    public static native boolean isatty(int filedes);
+
+    public static native void getTerminalSize(int filedes, MutableTerminalSize size, FunctionResult result);
 }

src/test/groovy/net/rubygrapefruit/platform/TerminalTest.groovy

@@ -13,4 +13,13 @@ class TerminalTest extends Specification {
         !terminal.isTerminal(Terminal.Output.Stdout);
         !terminal.isTerminal(Terminal.Output.Stderr);
     }
+
+    def "cannot detemine terminal size from a test"() {
+        when:
+        terminal.getTerminalSize(Terminal.Output.Stdout)
+
+        then:
+        NativeException e = thrown()
+        e.message == 'Could not get terminal size. Errno is 25.'
+    }
 }