"cd" is a shell internal command, not a executable program.
Even you can change dir in java program by whatever means like JNA, when it exit, the current dir in shell is not changed, because the java program runs in another process than the shell.
But we still can do something about it.
eg. I want to make a new shell command called xcd, it popup a GUI shows a list let you select directories existed in bash history, and change current dir to it for you.
- in
~/.bashrc add a line:
xcd(){
XCDRES=`xcd.sh`
if [ "$XCDRES" ]; then
cd "$XCDRES"
fi
}
2.xcd.sh is
#!/bin/bash
java -cp $PATH1/xcd.jar neoe.xcd.Main
and add xcd.sh to PATH
- the java program is
package neoe.xcd;
import java.awt.Toolkit;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.StringSelection;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import javax.swing.JComponent;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.ListSelectionModel;
public class Main {
public static String getUserHomeDir() {
return System.getProperty("user.home");
}
public static void main(String[] args) throws Exception {
new Main().run();
}
public static String readString(InputStream ins, String enc) throws IOException {
if (enc == null)
enc = "UTF-8";
BufferedReader in = new BufferedReader(new InputStreamReader(ins, enc));
char[] buf = new char[1000];
int len;
StringBuffer sb = new StringBuffer();
while ((len = in.read(buf)) > 0) {
sb.append(buf, 0, len);
}
in.close();
return sb.toString();
}
private String[] selection = new String[1];
private void run() throws Exception {
File hisfile = new File(getUserHomeDir(), ".bash_history");
if (!hisfile.exists()) {
System.err.println(".bash_history not exists, quit");
return;
}
String[] ss = readString(new FileInputStream(hisfile), null).split("\n");
List<String> res = new ArrayList<String>();
Set uniq = new HashSet();
for (String s : ss) {
s = s.trim();
if (!s.startsWith("cd /")) {
continue;
}
s = s.substring(3);
File f = new File(s);
if (f.isDirectory()) {
s = f.getAbsolutePath();
if (uniq.contains(s)) {
continue;
}
uniq.add(s);
res.add(s);
}
}
if (res.isEmpty()) {
System.err.println("no cd entry, quit");
return;
}
Collections.sort(res);
String cd1 = selectFromList(res);
if (cd1 == null) {
System.err.println("not selected, quit");
return;
}
doCd(cd1);
}
private void doCd(String cd1) throws Exception {
System.out.println(cd1);
}
private String selectFromList(List<String> res) {
final JList list = new JList(res.toArray());
list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
final JDialog frame = wrapFrame(new JScrollPane(list), "select dir to cd");
list.addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent e) {
if (e.getClickCount() > 1) {
String s = (String) list.getSelectedValue();
selection[0] = s;
frame.dispose();
}
}
});
list.addKeyListener(new KeyAdapter() {
@Override
public void keyPressed(KeyEvent e) {
int kc = e.getKeyCode();
if (kc == KeyEvent.VK_ESCAPE) {
frame.dispose();
} else if (kc == KeyEvent.VK_ENTER) {
String s = (String) list.getSelectedValue();
selection[0] = s;
frame.dispose();
}
}
});
frame.setVisible(true);
frame.requestFocus();
return selection[0];
}
private JDialog wrapFrame(JComponent comp, String title) {
JDialog frame = new JDialog();
frame.setTitle("select dir to cd");
frame.setModal(true);
frame.add(comp);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setSize(400, 600);
frame.setLocationRelativeTo(null);
return frame;
}
}
- use
xcd in shell.
