refactor: reorganize directory structure

assignment1/default.nix

@@ -0,0 +1,22 @@
+let
+  basic-c = name: { stdenv }:
+    stdenv.mkDerivation {
+      inherit name;
+      src = ./.;
+      buildPhase = ''
+        runHook preBuild
+        gcc part2/${name}.c -o ${name}
+        runHook postBuild
+      '';
+      installPhase = ''
+        runHook preInstall
+        mkdir -p $out/bin
+        install ${name} $out/bin/
+        runHook postInstall
+      '';
+    };
+in {
+  a1-hello = basic-c "hello";
+  a1-employee = basic-c "employee";
+  a1-logwriter = basic-c "logwriter";
+}

assignment1/part2/employee.c

@@ -0,0 +1,34 @@
+#include <stdio.h>
+#include <string.h>
+
+int main() {
+  // Character array to store name
+  // In C, strings are arrays of characters ending with '\0'
+  char name[50];
+  int employee_id;
+  float hours_worked;
+
+  printf("OwlTech Employee Registration\n");
+  printf("=============================\n");
+
+  printf("Enter your name: ");
+  // fgets reads a line including spaces
+  // stdin means "standard input" (keyboard)
+  fgets(name, sizeof(name), stdin);
+
+  // Remove newline that fgets includes
+  name[strcspn(name, "\n")] = '\0';
+
+  printf("Enter your employee ID: ");
+  // & means "address of" - scanf needs to know where to store the value
+  scanf("%d", &employee_id);
+  printf("Hours worked this week: ");
+  scanf("%f", &hours_worked);
+
+  printf("\nEmployee Summary:\n");
+  printf("Name: %s\n", name); // %s for string
+  printf("ID: %d\n", employee_id); // %d for integer
+  printf("Hours: %.2f\n", hours_worked); // %.2f for float with 2 decimals
+
+  return 0;
+}

assignment1/part2/hello.c

@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int main() {
+  printf("Welcome to OwlTech Industries!\n");
+  printf("Systems Programming Division\n");
+
+  return 0;
+}

assignment1/part2/logwriter.c

@@ -0,0 +1,39 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <time.h>
+
+int main() {
+  FILE *logfile; // Pointer to file structure
+  char message[100];
+  time_t current_time;
+
+  // Open file for appending ("a" mode)
+  // "w" would overwrite, "r" would read
+  logfile = fopen("owltech.log", "a");
+
+  // Always check if file opened successfully
+  if (logfile == NULL) {
+    printf("Error: Could not open log file\n");
+    return 1; // Return non-zero to indicate error
+  }
+
+  printf("Enter log message: ");
+  fgets(message, sizeof(message), stdin);
+
+  // Get current time
+  time(&current_time);
+
+  // Write to file with timestamp
+  // fprintf works like printf but writes to a file
+  fprintf(logfile, "[%s] %s", ctime(&current_time), message);
+
+  // Always close files when done
+  fclose(logfile);
+  printf("Log entry saved successfully!\n");
+
+  // Display the log file contents
+  printf("\n--- Current Log Contents ---\n");
+  system("cat owltech.log");
+
+  return 0;
+}