[FEATURE] Ping Command #58

src/main/java/com/mycmd/App.java

@@ -77,6 +77,7 @@ private static void registerCommands(Map<String, Command> commands) {
         commands.put("tree", new TreeCommand());
         commands.put("date", new DateCommand());
         commands.put("history", new HistoryCommand());
+        commands.put("ping", new PingCommand());
         commands.put("pwd", new PwdCommand());
         commands.put("uptime", new UptimeCommand());
         commands.put("clearhistory", new ClearHistoryCommand());

src/main/java/com/mycmd/commands/PingCommand.java

@@ -1,49 +1,181 @@
+package com.mycmd.commands;
+
+import com.mycmd.Command;
+import com.mycmd.ShellContext;
+
 import java.io.BufferedReader;
+import java.io.IOException;
 import java.io.InputStreamReader;
 
 /**
- * Executes the system ping command to test network connectivity.
+ * Tests network connectivity to a given hostname or IP address.
+ * 
+ * This command wraps the system ping utility to send ICMP echo requests
+ * and displays response times or timeout status for each attempt. It uses
+ * the native ping command available on the operating system.
  * 
- * This is a standalone utility that wraps the Windows cmd.exe ping command.
- * It executes the ping command as a subprocess and displays the output to
- * the user, including network round-trip times and packet statistics.
+ * Usage:
+ * - ping <hostname>     : Ping the specified host with default count (4 packets)
+ * - ping <hostname> -t  : Ping continuously until stopped (Windows-style)
+ * - ping <hostname> -n <count> : Ping with specified packet count (Windows-style)
  * 
- * Usage: java PingCommand hostname
+ * Examples:
+ * - ping google.com
+ * - ping 8.8.8.8
+ * - ping google.com -n 10
  * 
- * Note: This implementation is Windows-specific as it uses "cmd.exe /c ping".
- * The command requires at least one argument (the hostname or IP address to ping).
- * It waits for the ping process to complete and displays the exit code.
+ * Note: This implementation uses the system's native ping command for
+ * accurate network connectivity testing and proper ICMP handling.
  */
-public class PingCommand {
-    public static void main(String[] args) {
-        if (args.length < 1) {
-            System.out.println("Usage: java PingCommand <hostname>");
+public class PingCommand implements Command {
+
+    @Override
+    public void execute(String[] args, ShellContext context) throws IOException {
+        if (args.length == 0) {
+            System.out.println("Usage: ping <hostname> [options]");
+            System.out.println("Options:");
+            System.out.println("  -t          Ping continuously until stopped");
+            System.out.println("  -n <count>  Number of echo requests to send");
+            System.out.println();
+            System.out.println("Examples:");
+            System.out.println("  ping google.com");
+            System.out.println("  ping 8.8.8.8");
+            System.out.println("  ping google.com -n 10");
             return;
         }
 
         String host = args[0];
+
+        // Build ping command based on operating system
+        String[] command = buildPingCommand(host, args);
 
         try {
-            // Run the ping command
-            Process process = Runtime.getRuntime().exec("cmd.exe /c ping " + host);
+            // Execute the ping command
+            ProcessBuilder pb = new ProcessBuilder(command);
+            Process process = pb.start();
 
-            // Read the output of the ping command
+            // Read and display output in real-time
             BufferedReader reader = new BufferedReader(
                     new InputStreamReader(process.getInputStream())
             );
+            BufferedReader errorReader = new BufferedReader(
+                    new InputStreamReader(process.getErrorStream())
+            );
 
             String line;
+            // Display standard output
             while ((line = reader.readLine()) != null) {
                 System.out.println(line);
             }
+
+            // Display error output if any
+            while ((line = errorReader.readLine()) != null) {
+                System.err.println(line);
+            }
 
-            // Wait for the process to finish
+            // Wait for the process to complete
             int exitCode = process.waitFor();
-            System.out.println("Ping command exited with code: " + exitCode);
+
+            if (exitCode != 0) {
+                System.out.println("Ping command failed with exit code: " + exitCode);
+            }
 
-        } catch (Exception e) {
-            System.out.println("Error executing ping command.");
-            e.printStackTrace();
+        } catch (InterruptedException e) {
+            System.out.println("Ping command was interrupted.");
+            Thread.currentThread().interrupt();
+        } catch (IOException e) {
+            throw new IOException("Failed to execute ping command: " + e.getMessage(), e);
         }
     }
+
+    /**
+     * Builds the appropriate ping command based on the operating system and arguments.
+     */
+    private String[] buildPingCommand(String host, String[] args) {
+        String os = System.getProperty("os.name").toLowerCase();
+
+        if (os.contains("win")) {
+            return buildWindowsPingCommand(host, args);
+        } else {
+            return buildUnixPingCommand(host, args);
+        }
+    }
+
+    /**
+     * Builds ping command for Windows systems.
+     */
+    private String[] buildWindowsPingCommand(String host, String[] args) {
+        java.util.List<String> command = new java.util.ArrayList<>();
+        command.add("ping");
+
+        // Parse arguments for Windows ping options
+        boolean continuous = false;
+        int count = 4; // Default count
+
+        for (int i = 1; i < args.length; i++) {
+            if ("-t".equals(args[i])) {
+                continuous = true;
+            } else if ("-n".equals(args[i]) && i + 1 < args.length) {
+                try {
+                    count = Integer.parseInt(args[i + 1]);
+                    i++; // Skip the next argument as it's the count value
+                } catch (NumberFormatException e) {
+                    System.out.println("Warning: Invalid count value, using default (4)");
+                }
+            }
+        }
+
+        if (continuous) {
+            command.add("-t");
+        } else {
+            command.add("-n");
+            command.add(String.valueOf(count));
+        }
+
+        command.add(host);
+        return command.toArray(new String[0]);
+    }
+
+    /**
+     * Builds ping command for Unix-like systems (Linux, macOS).
+     */
+    private String[] buildUnixPingCommand(String host, String[] args) {
+        java.util.List<String> command = new java.util.ArrayList<>();
+        command.add("ping");
+
+        // Parse arguments for Unix ping options
+        int count = 4; // Default count
+
+        for (int i = 1; i < args.length; i++) {
+            if ("-t".equals(args[i])) {
+                // Unix ping doesn't use -t, just omit count for continuous
+                count = -1;
+            } else if ("-n".equals(args[i]) && i + 1 < args.length) {
+                try {
+                    count = Integer.parseInt(args[i + 1]);
+                    i++; // Skip the next argument as it's the count value
+                } catch (NumberFormatException e) {
+                    System.out.println("Warning: Invalid count value, using default (4)");
+                }
+            }
+        }
+
+        if (count > 0) {
+            command.add("-c");
+            command.add(String.valueOf(count));
+        }
+
+        command.add(host);
+        return command.toArray(new String[0]);
+    }
+
+    @Override
+    public String description() {
+        return "Tests network connectivity to a hostname or IP address";
+    }
+
+    @Override
+    public String usage() {
+        return "ping <hostname> [options]";
+    }
 }