[Add] Implement build system for user scripts.

assets/scripts/bin/build.lua

@@ -0,0 +1,27 @@
+-- /bin/build - "Compiles" a .lua file into an executable.
+local source_filename = arg[1]
+
+if not source_filename then
+  return "build: missing file operand"
+end
+
+-- Check for .lua extension.
+if not source_filename:match("%.lua$") then
+  return "build: input file must be a .lua file"
+end
+
+local current_dir = bettola.get_current_dir(context)
+local source_node = current_dir.children[source_filename]
+
+if not source_node then
+  return "build: cannot open '" .. source_filename .."': No such file"
+end
+
+if source_node.type ~= 0 then
+  return "build: '" .. source_filename .. "' is not a regular file"
+end
+
+local executable_filename = source_filename:gsub("%.lua$", "")
+local source_content = source_node.content
+
+return bettola.create_executable(context, executable_filename, source_content)

common/src/lua_api.cpp

@@ -78,6 +78,50 @@ std::string write_file(Session& context, const std::string& path,
   return "";
 }
 
+std::string create_executable(Session& context, const std::string& path,
+                              const std::string& content) {
+  vfs_node* parent_dir = nullptr;
+  std::string filename;
+
+  if(path[0] == '/') {
+    Machine* session_machine = context.get_session_machine();
+    vfs_node* root = session_machine->vfs_root;
+
+    size_t last_slash = path.find_last_of('/');
+    if(last_slash == 0) {
+      parent_dir = root;
+      filename = path.substr(1);
+    } else {
+      std::string parent_path = path.substr(0, last_slash);
+      parent_dir = find_node_by_path(root, parent_path);
+      filename = path.substr(last_slash+1);
+    }
+  } else {
+    parent_dir = context.get_current_dir();
+    filename = path;
+  }
+
+  if(!parent_dir) {
+    return "create_executable: cannot create file '" + path + "': No such file or directory";
+  }
+
+  if(parent_dir->type != DIR_NODE) {
+    return "create_executable: cannot create file in '" + get_full_path(parent_dir)
+        + "': Not a directory";
+  }
+
+  /* Overwrite if exists. */
+  auto it = parent_dir->children.find(filename);
+  if(it != parent_dir->children.end()) {
+    delete it->second;
+    parent_dir->children.erase(it);
+  }
+  vfs_node* new_exec = new_node(filename, EXEC_NODE, parent_dir);
+  new_exec->content = content;
+  parent_dir->children[filename] = new_exec;
+  return "";
+}
+
 std::string cd(Session& context, const std::string& path) {
   vfs_node* current_dir = context.get_current_dir();
 

common/src/lua_api.h

@@ -13,6 +13,8 @@ vfs_node* get_current_dir(Session& context);
 std::string rm(Session& context, const std::string& filename);
 std::string write_file(Session& context, const std::string& path,
                        const std::string& content);
+std::string create_executable(Session& context, const std::string& path,
+                              const std::string& content);
 std::string ls(Session& context);
 std::string cd(Session& context, const std::string& path);
 std::string scp(Session& context, const std::string& source,

common/src/lua_processor.cpp

@@ -26,6 +26,7 @@ LuaProcessor::LuaProcessor(Session& context) {
   bettola_api.set_function("rm",                &api::rm);
   bettola_api.set_function("ls",                &api::ls);
   bettola_api.set_function("write_file",        &api::write_file);
+  bettola_api.set_function("create_executable", &api::create_executable);
   bettola_api.set_function("get_current_dir",   &api::get_current_dir);
   bettola_api.set_function("cd",                &api::cd);
   bettola_api.set_function("scp",               &api::scp);

common/src/session.cpp

@@ -93,23 +93,36 @@ std::string Session::process_command(const std::string& command) {
     args.push_back(arg);
   }
 
-  /* Find the /bin directory in the current machine's VFS. */
+  vfs_node* command_node = nullptr;
+  if(command_name.find('/') != std::string::npos) {
+    /* Path provided, find node directly. */
+    command_node = find_node_by_path(_session_machine->vfs_root, command_name);
+  } else {
+    /* No path, search current dir then /bin. */
+    vfs_node* current_dir = get_current_dir();
+    if(current_dir->children.count(command_name)) {
+      command_node = current_dir->children.at(command_name);
+    } else {
       vfs_node* bin_dir = find_node_by_path(_session_machine->vfs_root, "/bin");
-  if(bin_dir && bin_dir->type == DIR_NODE) {
+      if(bin_dir && bin_dir->children.count(command_name)) {
-    auto it = bin_dir->children.find(command_name);
+        command_node = bin_dir->children.at(command_name);
-    if(it != bin_dir->children.end()) {
-      vfs_node* command_node = it->second;
-      if(command_node->type == EXEC_NODE) {
-        /* Execute the script. */
-        bool is_remote = (_session_machine != _home_machine);
-        sol::object result = lua.execute(command_node->content, *this, args, is_remote);
-        return result.is<std::string>() ? result.as<std::string>()
-            : "[Script returned an unexpected type]";
       }
     }
   }
 
-  return "Unknown command: " + command_name + "\n";
+  if(command_node) {
+    if(command_node->type == EXEC_NODE) {
+      bool is_remote = (_session_machine != _home_machine);
+      sol::object result = lua.execute(command_node->content, *this, args, is_remote);
+      return result.is<std::string>() ? result.as<std::string>()
+                                      : "[Script returned non-string value]";
+    } else if(command_node->type == DIR_NODE) {
+      return "Cannot execute '" + command_name + "' It is a directory.";
+    } else {
+      return "Cannot execute '" + command_name + "': Not an executable file.";
+    }
+  }
+  return "Unknown command: " + command_name;
 }
 
 std::string Session::write_file(const std::string& path, const std::string& content) {