Initial check in of some of the ban stuff.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@1162 6335cc39-0255-0410-8fd6-9bcaacd3b74c

projects/samskivert/src/java/com/samskivert/net/MACUtil.java

@@ -0,0 +1,114 @@
+//
+// $Id: MACUtil.java,v 1.1 2003/07/07 01:40:59 eric Exp $
+
+package com.samskivert.net;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import com.samskivert.Log;
+import com.samskivert.util.RunAnywhere;
+
+/**
+ * Attempts to find all the MAC addresses on the machine.
+ * This is accomplished by calling external programs specific
+ * to the platform we are on, and parsing the results.
+ */
+public class MACUtil
+{
+    /**
+     * Get all the MAC addresses of the hardware we are running on that we
+     * can find.
+     */
+    public static String[] getMACAddresses ()
+    {
+        String [] cmds;
+        if (RunAnywhere.isWindows()) {
+            cmds = WINDOWS_CMDS;
+        } else {
+            cmds = UNIX_CMDS;
+        }
+
+        return parseMACs(tryCommands(cmds));
+    }
+
+    /**
+     * Look through the text for all the MAC addresses we can find.
+     */
+    protected static String[] parseMACs (String text)
+    {
+        Matcher m = MACRegex.matcher(text);
+
+        ArrayList list = new ArrayList();
+        while (m.find()) {
+            list.add(m.group(1));
+        }
+        return (String[])list.toArray();
+    }
+
+    /**
+     * Takes a lists of commands and trys to run each one till one works.
+     * The idea being to beable to 'gracefully' cope with not knowing
+     * where a command is installed on different installations.
+     */
+    protected static String tryCommands (String[] cmds)
+    {
+        if (cmds == null) {
+            return null;
+        }
+
+        String output;
+
+        for (int ii = 0; ii < cmds.length; ii++) {
+            output = runCommand(cmds[ii]);
+            if (output != null) {
+                return output;
+            }
+        }
+        
+        return null;
+    }
+    
+    /**
+     * Run the specificed command and return the output as a string.
+     */
+    protected static String runCommand (String cmd)
+    {
+        try {
+            Process p = Runtime.getRuntime().exec(cmd);
+            BufferedReader cin = new BufferedReader(
+                new InputStreamReader(p.getInputStream()));
+            StringBuffer buffer= new StringBuffer();
+            
+            String line = "";
+            while (line != null)
+            {
+                buffer.append(line);
+                line = cin.readLine();
+            }
+            cin.close();
+            
+            return buffer.toString();
+        } catch (IOException e) {
+            // don't want to log anything for the client to know what we
+            // are doing.  This will almost always be thrown/caught when
+            // the cmd isn't there.
+            return null;
+        }
+    }
+
+    /** Look for 2 hex values in a row followed by a ':' repeated 5 times,
+        followed by 2 hex values. */
+    protected static Pattern MACRegex =
+        Pattern.compile("((?:\\p{XDigit}{2}+:){5}+\\p{XDigit}{2}+)",
+                        Pattern.CASE_INSENSITIVE);
+
+    // TODO maybe we should obfuscate these with rot13 or something so
+    // that people can't run 'strings' on us and instantly see what we try
+    protected static String[] WINDOWS_CMDS = {"ipconfig"};
+    protected static String[] UNIX_CMDS = {"/sbin/ifconfig", "/etc/ifconfig"};
+}