diff --git a/RedPandaIDE/RedPandaIDE.pro b/RedPandaIDE/RedPandaIDE.pro
index 1765af11..8b4d650c 100644
--- a/RedPandaIDE/RedPandaIDE.pro
+++ b/RedPandaIDE/RedPandaIDE.pro
@@ -14,6 +14,7 @@ SOURCES += \
     main.cpp \
     mainwindow.cpp \
     settings.cpp \
+    systemconsts.cpp \
     utils.cpp
 
 HEADERS += \
@@ -21,6 +22,7 @@ HEADERS += \
     editorlist.h \
     mainwindow.h \
     settings.h \
+    systemconsts.h \
     utils.h
 
 FORMS += \
diff --git a/RedPandaIDE/editor.cpp b/RedPandaIDE/editor.cpp
index 1f1ad239..a4684e9f 100644
--- a/RedPandaIDE/editor.cpp
+++ b/RedPandaIDE/editor.cpp
@@ -8,6 +8,7 @@
 #include <memory>
 #include "settings.h"
 #include "mainwindow.h"
+#include "systemconsts.h"
 #include <Qsci/qscilexercpp.h>
 #include <QFileDialog>
 #include <QMessageBox>
@@ -15,6 +16,19 @@
 
 using namespace std;
 
+SaveException::SaveException(const QString& reason) {
+    mReason = reason;
+}
+SaveException::SaveException(const QString&& reason) {
+    mReason = reason;
+}
+const QString& SaveException::reason() const  noexcept{
+    return mReason;
+}
+const char *SaveException::what() const noexcept {
+    return mReason.toLocal8Bit();
+}
+
 
 Editor::Editor(QWidget *parent, const QString& filename,
                   const QByteArray& encoding,
@@ -92,6 +106,8 @@ Editor::Editor(QWidget *parent, const QString& filename,
             this, SLOT(onCursorPositionChanged(int,int)));
     connect(this, SIGNAL(linesChanged()),
             this,SLOT(onLinesChanged()));
+
+    this->toggleComment
 }
 
 Editor::~Editor() {
@@ -107,7 +123,13 @@ Editor::~Editor() {
 
 void Editor::loadFile() {
     QFile file(mFilename);
-    QByteArray content=file.read(file.bytesAvailable());
+    if (!file.open(QFile::ReadOnly)) {
+        QMessageBox::information(pMainWindow,
+                                 tr("Error"),
+                                 QString(tr("Can't Open File %1:%2")).arg(mFilename).arg(file.errorString()));
+    }
+    QByteArray content=file.readAll();
+    file.close();
     if (mEncodingOption == ENCODING_AUTO_DETECT) {
         mFileEncoding = GuessTextEncoding(content);
     } else {
@@ -119,6 +141,8 @@ void Editor::loadFile() {
         this->setText(QString::fromUtf8(content.mid(3)));
     } else if (mFileEncoding == ENCODING_ASCII) {
         this->setText(QString::fromLatin1(content));
+    } else if (mFileEncoding == ENCODING_SYSTEM_DEFAULT) {
+        this->setText(QString::fromLocal8Bit(content));
     }else {
         QTextCodec*codec = QTextCodec::codecForName(mFileEncoding);
         this->setText(codec->toUnicode(content));
@@ -148,30 +172,42 @@ void Editor::saveFile(const QString &filename) {
             ba.append(this->text().toUtf8());
     } else if (mFileEncoding == ENCODING_ASCII) {
         ba = this->text().toLatin1();
+    } else if (mFileEncoding == ENCODING_SYSTEM_DEFAULT) {
+        ba = this->text().toLocal8Bit();
     } else {
         QTextCodec* codec = QTextCodec::codecForName(mFileEncoding);
         ba = codec->fromUnicode(this->text());
     }
-    file.open(QFile::WriteOnly);
-    file.write(ba);
-    file.close();
+    if (file.open(QFile::WriteOnly)) {
+        if (file.write(ba)<0) {
+            throw SaveException(QString(tr("Failed to Save file %1: %2")).arg(filename).arg(file.errorString()));
+        }
+        file.close();
+    } else {
+        throw SaveException(QString(tr("Failed to Open file %1: %2")).arg(filename).arg(file.errorString()));
+    }
 }
 
 bool Editor::save(bool force, bool reparse) {
     if (this->mIsNew) {
         return saveAs();
     }
-    QFile file(mFilename);
     QFileInfo info(mFilename);
+    //is this file writable;
     if (!force && !info.isWritable()) {
         QMessageBox::information(pMainWindow,tr("Fail"),
                                  QString(QObject::tr("File %s is not writable!")));
         return false;
     }
-    //is this file read-only?
     if (this->isModified() || force) {
-        saveFile(mFilename);
-        setModified(false);
+        try {
+            saveFile(mFilename);
+            setModified(false);
+        }  catch (SaveException& exception) {
+            QMessageBox::information(pMainWindow,tr("Fail"),
+                                     exception.reason());
+            return false;
+        }
     }
 
     if (reparse) {
@@ -181,15 +217,23 @@ bool Editor::save(bool force, bool reparse) {
 }
 
 bool Editor::saveAs(){
+    QString selectedFileFilter = pSystemConsts->defaultFileFilter();
     QString newName = QFileDialog::getSaveFileName(pMainWindow,
-                                                   tr("Save As"));
+        tr("Save As"), QString(), pSystemConsts->defaultFileFilters().join(";;"),
+        &selectedFileFilter);
     if (newName.isEmpty()) {
         return false;
     }
-    saveFile(newName);
-    mFilename = newName;
-    mIsNew = false;
-    setModified(false);
+    try {
+        saveFile(mFilename);
+        mFilename = newName;
+        mIsNew = false;
+        setModified(false);
+    }  catch (SaveException& exception) {
+        QMessageBox::information(pMainWindow,tr("Fail"),
+                                 exception.reason());
+        return false;
+    }
 
     //todo: update (reassign highlighter)
     //todo: remove old file from parser and reparse file
@@ -199,26 +243,26 @@ bool Editor::saveAs(){
     return true;
 }
 
-const QByteArray& Editor::encodingOption() const {
+const QByteArray& Editor::encodingOption() const noexcept{
     return mEncodingOption;
 }
-void Editor::setEncodingOption(const QByteArray& encoding) {
+void Editor::setEncodingOption(const QByteArray& encoding) noexcept{
     mEncodingOption = encoding;
 }
-const QByteArray& Editor::fileEncoding() const {
+const QByteArray& Editor::fileEncoding() const noexcept{
     return mFileEncoding;
 }
-const QString& Editor::filename() {
+const QString& Editor::filename() const noexcept{
     return mFilename;
 }
-bool Editor::inProject() const {
+bool Editor::inProject() const noexcept{
     return mInProject;
 }
-bool Editor::isNew() const {
+bool Editor::isNew() const noexcept {
     return mIsNew;
 }
 
-QTabWidget* Editor::pageControl() {
+QTabWidget* Editor::pageControl() noexcept{
     return mParentPageControl;
 }
 
@@ -232,17 +276,15 @@ void Editor::wheelEvent(QWheelEvent *event) {
     }
 }
 
-void Editor::onModificationChanged(bool status) {
+void Editor::onModificationChanged(bool) {
     updateCaption();
 }
 
-void Editor::onCursorPositionChanged(int line, int index)
-{
+void Editor::onCursorPositionChanged(int line, int index) {
     pMainWindow->updateStatusBarForEditingInfo(line,index+1,lines(),text().length());
 }
 
-void Editor::onLinesChanged()
-{
+void Editor::onLinesChanged() {
     qDebug()<<"lala"<<lines();
 }
 
diff --git a/RedPandaIDE/editor.h b/RedPandaIDE/editor.h
index 714ca88b..db1fe86e 100644
--- a/RedPandaIDE/editor.h
+++ b/RedPandaIDE/editor.h
@@ -6,6 +6,19 @@
 #include <QTabWidget>
 #include <Qsci/qsciscintilla.h>
 
+class SaveException: public std::exception {
+
+public:
+    explicit SaveException(const QString& reason);
+    explicit SaveException(const QString&& reason);
+    // exception interface
+    const QString& reason() const noexcept;
+public:
+    const char *what() const noexcept override;
+private:
+    QString mReason;
+};
+
 class Editor : public QsciScintilla
 {
     Q_OBJECT
@@ -22,19 +35,19 @@ public:
     Editor& operator=(const Editor&) = delete;
     Editor& operator=(const Editor&&) = delete;
 
-    const QByteArray& encodingOption() const;
-    void setEncodingOption(const QByteArray& encoding);
-    const QByteArray& fileEncoding() const;
-    const QString& filename();
-    bool inProject() const;
-    bool isNew() const;
+    const QByteArray& encodingOption() const noexcept;
+    void setEncodingOption(const QByteArray& encoding) noexcept;
+    const QByteArray& fileEncoding() const noexcept;
+    const QString& filename() const noexcept;
+    bool inProject() const noexcept;
+    bool isNew() const noexcept;
 
     void loadFile();
     void saveFile(const QString& filename);
     bool save(bool force=false, bool reparse=true);
     bool saveAs();
 
-    QTabWidget* pageControl();
+    QTabWidget* pageControl() noexcept;
 
     void updateCaption(const QString& newCaption=QString());
 
@@ -42,9 +55,9 @@ signals:
 
 
 protected slots:
-    void onModificationChanged(bool status);
-    void onCursorPositionChanged(int line, int index);
-    void onLinesChanged();
+    void onModificationChanged(bool status) ;
+    void onCursorPositionChanged(int line, int index) ;
+    void onLinesChanged() ;
 
 private:
     QByteArray mEncodingOption; // the encoding type set by the user
diff --git a/RedPandaIDE/editorlist.cpp b/RedPandaIDE/editorlist.cpp
index e66dd8c9..57987a9f 100644
--- a/RedPandaIDE/editorlist.cpp
+++ b/RedPandaIDE/editorlist.cpp
@@ -123,3 +123,20 @@ bool EditorList::closeAll(bool force) {
 
     return true;
 }
+
+Editor* EditorList::findOpenedEditor(const QString &filename)
+{
+    for (int i=0;i<mLeftPageWidget->count();i++) {
+        Editor* e = static_cast<Editor*>(mLeftPageWidget->widget(i));
+        if (e->filename() == filename) {
+            return e;
+        }
+    }
+    for (int i=0;i<mRightPageWidget->count();i++) {
+        Editor* e = static_cast<Editor*>(mRightPageWidget->widget(i));
+        if (e->filename() == filename) {
+            return e;
+        }
+    }
+    return nullptr;
+}
diff --git a/RedPandaIDE/editorlist.h b/RedPandaIDE/editorlist.h
index 036a9c3a..953f40a4 100644
--- a/RedPandaIDE/editorlist.h
+++ b/RedPandaIDE/editorlist.h
@@ -40,6 +40,8 @@ public:
 
     bool closeAll(bool force = false);
 
+    Editor* findOpenedEditor(const QString& filename);
+
     void beginUpdate();
     void endUpdate();
 
diff --git a/RedPandaIDE/main.cpp b/RedPandaIDE/main.cpp
index 3ffa97a2..bb5b2059 100644
--- a/RedPandaIDE/main.cpp
+++ b/RedPandaIDE/main.cpp
@@ -1,14 +1,17 @@
 #include "mainwindow.h"
 #include "settings.h"
+#include "systemconsts.h"
 #include <QApplication>
 
 int main(int argc, char *argv[])
 {
-    QApplication a(argc, argv);
-    Settings s;
-    pSettings = &s;
-    MainWindow w;
-    pMainWindow = &w;
-    w.show();
-    return a.exec();
+    QApplication app(argc, argv);
+    SystemConsts systemConsts;
+    pSystemConsts = &systemConsts;
+    Settings settings;
+    pSettings = &settings;
+    MainWindow mainWindow;
+    pMainWindow = &mainWindow;
+    mainWindow.show();
+    return app.exec();
 }
diff --git a/RedPandaIDE/mainwindow.cpp b/RedPandaIDE/mainwindow.cpp
index 69ca75c4..0a01530f 100644
--- a/RedPandaIDE/mainwindow.cpp
+++ b/RedPandaIDE/mainwindow.cpp
@@ -2,8 +2,11 @@
 #include "ui_mainwindow.h"
 #include "editorlist.h"
 #include "editor.h"
+#include "systemconsts.h"
+#include "settings.h"
 
 #include <QCloseEvent>
+#include <QFileDialog>
 #include <QLabel>
 
 MainWindow* pMainWindow;
@@ -50,6 +53,28 @@ void MainWindow::updateStatusBarForEditingInfo(int line,int col,int lines,int ch
     }
 }
 
+void MainWindow::openFiles(const QStringList &files)
+{
+    mEditorList->beginUpdate();
+    for (QString file:files) {
+        openFile(file);
+    }
+    mEditorList->endUpdate();
+}
+
+void MainWindow::openFile(const QString &filename)
+{
+    Editor* editor = mEditorList->findOpenedEditor(filename);
+    if (editor!=nullptr) {
+        editor->setFocus();
+        return;
+    }
+    editor = mEditorList->newEditor(filename,ENCODING_AUTO_DETECT,
+                                    false,false);
+    editor->setFocus();
+    this->updateStatusBarForEncoding();
+}
+
 void MainWindow::setupActions() {
 
 }
@@ -69,10 +94,11 @@ void MainWindow::on_EditorTabsLeft_tabCloseRequested(int index)
 
 void MainWindow::on_actionOpen_triggered()
 {
-    Editor * editor = mEditorList->getEditor();
-    if (editor != NULL) {
-        //editor->save();
-    }
+    QString selectedFileFilter = pSystemConsts->defaultFileFilter();
+    QStringList files = QFileDialog::getOpenFileNames(pMainWindow,
+        tr("Open"), QString(), pSystemConsts->defaultFileFilters().join(";;"),
+        &selectedFileFilter);
+    openFiles(files);
 }
 
 void MainWindow::closeEvent(QCloseEvent *event) {
diff --git a/RedPandaIDE/mainwindow.h b/RedPandaIDE/mainwindow.h
index 903c1064..a85e675f 100644
--- a/RedPandaIDE/mainwindow.h
+++ b/RedPandaIDE/mainwindow.h
@@ -21,7 +21,9 @@ public:
     void updateStatusBarForEncoding();
     void updateStatusBarForEditingInfo(int line,int col,int lines,int charCount);
 
-
+protected:
+    void openFiles(const QStringList& files);
+    void openFile(const QString& filename);
 private slots:
     void on_actionNew_triggered();
 
diff --git a/RedPandaIDE/mainwindow.ui b/RedPandaIDE/mainwindow.ui
index fe4d886b..eb6a633f 100644
--- a/RedPandaIDE/mainwindow.ui
+++ b/RedPandaIDE/mainwindow.ui
@@ -222,6 +222,9 @@
    <property name="text">
     <string>New</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+N</string>
+   </property>
   </action>
   <action name="actionOpen">
    <property name="icon">
@@ -232,6 +235,9 @@
    <property name="text">
     <string>Open...</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+O</string>
+   </property>
   </action>
   <action name="actionSave">
    <property name="icon">
@@ -242,6 +248,9 @@
    <property name="text">
     <string>Save</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+S</string>
+   </property>
   </action>
   <action name="actionSaveAs">
    <property name="icon">
@@ -265,6 +274,9 @@
    <property name="text">
     <string>Save All</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+Shift+S</string>
+   </property>
   </action>
  </widget>
  <resources/>
diff --git a/RedPandaIDE/systemconsts.cpp b/RedPandaIDE/systemconsts.cpp
new file mode 100644
index 00000000..78bf30a1
--- /dev/null
+++ b/RedPandaIDE/systemconsts.cpp
@@ -0,0 +1,30 @@
+#include "systemconsts.h"
+#include <QObject>
+#include <QString>
+#include <QStringList>
+
+SystemConsts* pSystemConsts;
+
+SystemConsts::SystemConsts(): mDefaultFileFilters()
+{
+    addDefaultFileFilter(QObject::tr("C files"),"*.c");
+    addDefaultFileFilter(QObject::tr("C++ files"),"*.cpp *.cc *.cxx");
+    addDefaultFileFilter(QObject::tr("Header files"),"*.h *.hh");
+    addDefaultFileFilter(QObject::tr("Text files"),"*.txt");
+    addDefaultFileFilter(QObject::tr("All files"),"*");
+}
+
+const QStringList &SystemConsts::defaultFileFilters() const noexcept
+{
+    return mDefaultFileFilters;
+}
+
+const QString &SystemConsts::defaultFileFilter() const noexcept
+{
+    return mDefaultFileFilters[1];
+}
+
+void SystemConsts::addDefaultFileFilter(const QString &name, const QString &fileExtensions)
+{
+    mDefaultFileFilters.append(name+ " (" + fileExtensions+")");
+}
diff --git a/RedPandaIDE/systemconsts.h b/RedPandaIDE/systemconsts.h
new file mode 100644
index 00000000..1db0c64f
--- /dev/null
+++ b/RedPandaIDE/systemconsts.h
@@ -0,0 +1,18 @@
+#ifndef SYSTEMCONSTS_H
+#define SYSTEMCONSTS_H
+
+#include <QStringList>
+
+class SystemConsts
+{
+public:
+    SystemConsts();
+    const QStringList& defaultFileFilters() const noexcept;
+    const QString& defaultFileFilter() const noexcept;
+    void addDefaultFileFilter(const QString& name, const QString& fileExtensions);
+private:
+    QStringList mDefaultFileFilters;
+};
+
+extern SystemConsts* pSystemConsts;
+#endif // SYSTEMCONSTS_H