add development files for lab2

labs/2/Main.java

@@ -0,0 +1,89 @@
+import java.util.Objects;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.util.Scanner;
+import java.io.FileWriter;
+
+import java.net.URL;
+import java.io.BufferedInputStream;
+
+public class Main {
+    private boolean disable_networking = false;
+
+    public void main(String[] args) {
+        boolean help_enqueued = false;
+        int verbosity = 1;
+        
+        int p = 0;
+        while (p < args.length) {
+            try {
+                if (Objects.equals(args[p], "-h")) {    
+                    help_enqueued = true;
+                }
+                else if (Objects.equals(args[p], "-v")) {
+                    verbosity = Integer.parseInt(args[p+1]);
+                    p += 2;
+                }
+                else if (Objects.equals(args[p], "--offline")) {
+                    disable_networking = true;
+                    p += 2;
+                }
+                else {
+                    System.err.println("[ERROR] Unknown argument found: " + args[p] + "\n[ERROR] Please, use 'java Main -h' for help");
+                    System.exit(1);
+                }
+            }
+            catch (Exception e) {
+                System.err.println("[ERROR] Exception while parsing CLI arguments: " + e);
+                System.err.println("[ERROR] Aborting further execution.");
+                System.exit(1);
+            }
+        }
+
+        if (help_enqueued) {
+            printHelp();
+            System.exit(0);
+        }
+    }
+
+    public fetchResource(String remote_url, String output_filename) {
+        BufferedInputStream in = new BufferedInputStream(new URL(remote_url).openStream());
+        FileOutputStream fileOutputStream = new FileOutputStream()
+
+        byte dataBuffer[] = new byte[1024];
+        int bytesRead;
+        while ((bytesRead = in.read(dataBuffer, 0, 1024)) != -1) {
+            fileOutputStream.write(dataBuffer, 0, bytesRead);
+        }
+    }
+
+    public printHelp() {
+        String help_text = "";
+
+        try {
+            File help_file = new File("src/help.txt");
+            Scanner help_file_scanner = new Scanner(help_file);
+
+        } catch (FileNotFoundException e) {
+            System.err.println("[WARN] Help file missing.");
+            if (!disable_networking) {
+                System.err.println("[INFO] Trying to recover it from the git server");
+                fetchResource("http://139.162.162.130:3000/", "src/help.txt");
+                File help_file = new File("src/help.txt");
+                Scanner help_file_scanner = new Scanner(help_file);
+            } else {
+                System.err.println("[INFO] --offline flag is set, not recovering");
+                System.exit(1);
+            }
+        }
+        
+        while (help_file_scanner.hasNextLine()) {
+            help_text += help_file_scanner.nextLine();
+        }
+
+        help_file_scanner.close();
+                    
+        System.out.println(help_text);
+    }
+}

labs/2/src/help.txt

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+Dummy help file