diff --git a/assets/scripts/bin/chgrp.lua b/assets/scripts/bin/chgrp.lua
new file mode 100644
index 0000000..709512d
--- /dev/null
+++ b/assets/scripts/bin/chgrp.lua
@@ -0,0 +1,9 @@
+-- /bin/chgrp - Change file group.
+local group = arg[1]
+local path  = arg[2]
+
+if not group or not path then
+  return "chgrp: missing operand"
+end
+
+return bettola.chgrp(context, group, path)
diff --git a/assets/scripts/bin/chown.lua b/assets/scripts/bin/chown.lua
new file mode 100644
index 0000000..78887f4
--- /dev/null
+++ b/assets/scripts/bin/chown.lua
@@ -0,0 +1,9 @@
+-- /bin/chown - Change file owner.
+local owner = arg[1]
+local path  = arg[2]
+
+if not owner or not path then
+  return "chown: missing operand"
+end
+
+return bettola.chown(context, owner, path)
diff --git a/assets/scripts/bin/ls.lua b/assets/scripts/bin/ls.lua
index 45aa967..45fbf86 100644
--- a/assets/scripts/bin/ls.lua
+++ b/assets/scripts/bin/ls.lua
@@ -16,6 +16,34 @@ local function format_permissions(perms)
   return table.concat(rwx)
 end
 
+local function get_username_from_uid(uid)
+  local passwd_content = bettola.read_file(context, "/etc/passwd")
+  for line in passwd_content:gmatch("(^\n]+)") do
+    local parts = {}
+    for part in line:gmatch("([^:]+)") do
+      table.insert(parts,part)
+    end
+    if #parts >= 3 and tonumber(parts[3]) == uid then
+      return parts[1]
+    end
+  end
+  return tostring(uid)
+end
+
+local function get_groupname_from_gid(gid)
+  local group_content = bettola.read_file(context, "/etc/group")
+  for line in group_content:gmatch("([^\n]+)") do
+    local parts = {}
+    for part in line:gmatch("([^:]+)") do
+      table.insert(parts, part)
+    end
+    if #parts >= 3 and tonumber(parts[3]) == gid then
+      return parts[1]
+    end
+  end
+  return tostring(gid)
+end
+
 local function get_file_size(node)
   if node.type == 0 then -- FILE_NODE.
     return #node.content
@@ -24,15 +52,34 @@ local function get_file_size(node)
   end
 end
 
+-- Cache for UID/GID to name mappings.
+local uid_to_name_cache = {}
+local gid_to_name_cache = {}
+
+local function get_cached_username(uid)
+  if not uid_to_name_cache[uid] then
+    uid_to_name_cache[uid] = get_username_from_uid(uid)
+  end
+  return uid_to_name_cache[uid]
+end
+
+local function get_cached_groupname(gid)
+  if not gid_to_name_cache[gid] then
+    gid_to_name_cache[gid] = get_groupname_from_gid(gid)
+  end
+  return gid_to_name_cache[gid]
+end
+
 local function ls_long_format(dir)
   local output = {}
   for name, node in pairs(dir.children) do
     local line_type = (node.type == 1) and "d" or "-"
     local perms = format_permissions(node.permissions)
-    local owner = node.owner_id
-    local group = node.group_id
+    local owner_name = get_cached_username(node.owner_id)
+    local group_name = get_cached_groupname(node.group_id)
     local size  = get_file_size(node)
-    table.insert(output, string.format("%s%s %d %d %5d %s", line_type, perms, owner, group, size, name))
+    table.insert(output, string.format("%s%s %s %s %5d %s", line_type, perms, owner_name,
+      group_name, size, name))
   end
   table.sort(output)
   return table.concat(output, "\n")
diff --git a/assets/scripts/bin/whoami.lua b/assets/scripts/bin/whoami.lua
new file mode 100644
index 0000000..f1eab6c
--- /dev/null
+++ b/assets/scripts/bin/whoami.lua
@@ -0,0 +1,2 @@
+-- /bin/whoami - Print the effective username of the current user.
+return bettola.get_username(context)
diff --git a/common/src/db/database_manager.cpp b/common/src/db/database_manager.cpp
index 343307f..b61d45f 100644
--- a/common/src/db/database_manager.cpp
+++ b/common/src/db/database_manager.cpp
@@ -71,8 +71,20 @@ bool DatabaseManager::create_player(const std::string& username, const std::stri
     /* Create default subdirs. */
     _vfs_repository->create_node(machine_id, &root_id, "home", DIR_NODE,
                                  "", player_id, player_id, 0755);
-    _vfs_repository->create_node(machine_id, &root_id, "etc", DIR_NODE,
-                                 "", player_id, player_id, 0755);
+    long long etc_id = _vfs_repository->create_node(machine_id, &root_id, "etc", DIR_NODE,
+                                                    "", 0, 0, 0755);
+
+    /* Create /etc/passwd and /etc/group. */
+    std::string passwd_content = "root:x:0:0\n";
+    passwd_content += username + ":x:" + std::to_string(player_id) + ":"
+      + std::to_string(player_id) + "\n";
+    _vfs_repository->create_node(machine_id, &etc_id, "passwd", FILE_NODE,
+                                 passwd_content, 0, 0, 0644);
+
+    std::string group_content = "root:x:\n";
+    group_content += username + ":x:" + std::to_string(player_id) + "\n";
+    _vfs_repository->create_node(machine_id, &etc_id, "group", FILE_NODE,
+                                 group_content, 0, 0, 0644);
 
     /* Create /bin and get it's ID */
     long long bin_id = _vfs_repository->create_node(machine_id, &root_id, "bin", DIR_NODE,
diff --git a/common/src/db/machine_repository.cpp b/common/src/db/machine_repository.cpp
index 01b0152..fcbe43a 100644
--- a/common/src/db/machine_repository.cpp
+++ b/common/src/db/machine_repository.cpp
@@ -47,3 +47,11 @@ std::string MachineRepository::get_hostname(long long machine_id) {
       >> hostname;
   return hostname;
 }
+
+long long MachineRepository::get_owner_id(long long machine_id) {
+  long long owner_id = -1;
+  _db << "SELECT owner_id FROM machines WHERE id = ?;"
+      << machine_id
+      >> owner_id;
+  return owner_id;
+}
diff --git a/common/src/db/machine_repository.h b/common/src/db/machine_repository.h
index c0af20a..1d10817 100644
--- a/common/src/db/machine_repository.h
+++ b/common/src/db/machine_repository.h
@@ -21,6 +21,7 @@ public:
   std::vector<MachineData> get_all_npcs(void);
   std::vector<MachineData> get_all(void);
   std::string get_hostname(long long machine_id);
+  long long get_owner_id(long long machine_id);
 
 private:
   sqlite::database& _db;
diff --git a/common/src/lua_api.cpp b/common/src/lua_api.cpp
index 84e0c32..8d9a739 100644
--- a/common/src/lua_api.cpp
+++ b/common/src/lua_api.cpp
@@ -1,3 +1,4 @@
+#include <exception>
 #include <sol/call.hpp>
 #include <sol/types.hpp>
 #include <sstream>
@@ -72,7 +73,9 @@ std::string write_file(Session& context, const std::string& path,
     it->second->content = content;
   } else {
     /* File does not exist, create it. */
-    vfs_node* new_file = new_node(filename, FILE_NODE, parent_dir);
+    uint32_t current_uid = context.get_home_machine()->owner_id;
+    vfs_node* new_file = new_node(filename, FILE_NODE, parent_dir, current_uid,
+                                  current_uid, 0644);
     new_file->content = content;
     parent_dir->children[filename] = new_file;
   }
@@ -117,12 +120,18 @@ std::string create_executable(Session& context, const std::string& path,
     delete it->second;
     parent_dir->children.erase(it);
   }
-  vfs_node* new_exec = new_node(filename, EXEC_NODE, parent_dir);
+  uint32_t current_uid = context.get_home_machine()->owner_id;
+  vfs_node* new_exec = new_node(filename, EXEC_NODE, parent_dir, current_uid,
+                                current_uid, 0755);
   new_exec->content = util::xor_string(content);
   parent_dir->children[filename] = new_exec;
   return "";
 }
 
+std::string read_file(Session& context, const std::string& path) {
+  return context.read_file(path);
+}
+
 std::string cd(Session& context, const std::string& path) {
   vfs_node* current_dir = context.get_current_dir();
 
@@ -213,6 +222,104 @@ std::string close_terminal(Session& context) {
   return "__CLOSE_CONNECTION__";
 }
 
+std::string get_username(Session& context) {
+  return context.get_username();
+}
+
+long long get_uid_from_name(Session& context, const std::string& username) {
+  vfs_node* passwd_node = find_node_by_path(context.get_home_machine()->vfs_root, "/etc/passwd");
+  if(!passwd_node || passwd_node->type != FILE_NODE) {
+    return -1;
+  }
+
+  std::stringstream ss(passwd_node->content);
+  std::string line;
+  while(std::getline(ss, line)) {
+    std::vector<std::string> parts;
+    std::stringstream line_ss(line);
+    std::string part;
+    while(std::getline(line_ss, part, ':')) {
+      parts.push_back(part);
+    }
+
+    if(parts.size() >= 3 && parts[0] == username) {
+      try {
+        return std::stoll(parts[2]);
+      } catch(const std::exception& e) {
+        return -1;
+      }
+    }
+  }
+  return -1;
+}
+
+std::string chown(Session& context, const std::string& owner, const std::string& path) {
+  vfs_node* node = find_node_by_path(context.get_session_machine()->vfs_root, path);
+  if(!node) {
+    return "chown: cannot access '" + path + "' No such file or directory";
+  }
+
+  long long new_uid = get_uid_from_name(context, owner);
+  if(new_uid == -1) {
+    return "chown: invalid user: '" + owner + "'";
+  }
+
+  uint32_t current_uid = context.get_home_machine()->owner_id;
+  if(node->owner_id != current_uid && current_uid != 0) {
+    return "chown: changing ownership of '" + path + "': Operation not permitted";
+  }
+
+  node->owner_id = new_uid;
+  return "";
+}
+
+long long get_gid_from_name(Session& context, const std::string& groupname) {
+  vfs_node* group_node = find_node_by_path(context.get_home_machine()->vfs_root, "/etc/group");
+  if(!group_node || group_node->type != FILE_NODE) {
+    return -1;
+  }
+
+  std::stringstream ss(group_node->content);
+  std::string line;
+  while(std::getline(ss, line)) {
+    std::vector<std::string> parts;
+    std::stringstream line_ss(line);
+    std::string part;
+    while(std::getline(line_ss, part, ':')) {
+      parts.push_back(part);
+    }
+
+    if(parts.size() >= 3 && parts[0] == groupname) {
+      try {
+        return std::stoll(parts[2]);
+      } catch(const std::exception& e) {
+        return -1;
+      }
+    }
+  }
+  return -1;
+}
+
+std::string chgrp(Session& context, const std::string& group, const std::string& path) {
+  vfs_node* node = find_node_by_path(context.get_session_machine()->vfs_root, path);
+  if(!node) {
+    return "chgrp: cannot access '" + path + "': No such file ordirectory";
+  }
+
+  long long new_gid = get_gid_from_name(context, group);
+  if(new_gid == -1) {
+    return "chgrp: invalid group: '" + group + "'";
+  }
+
+  uint32_t current_uid = context.get_home_machine()->owner_id;
+  if(node->owner_id != current_uid && current_uid != 0) {
+    return "chgrp: changing group of '" + path + "': Operation not permitted";
+  }
+
+  node->group_id = new_gid;
+  return "";
+}
+
 struct ScpPath {
   std::string host;
   std::string path;
diff --git a/common/src/lua_api.h b/common/src/lua_api.h
index fd27bd3..0dd5f2a 100644
--- a/common/src/lua_api.h
+++ b/common/src/lua_api.h
@@ -15,10 +15,15 @@ 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 read_file(Session& context, const std::string& path);
 std::string ls(Session& context);
 std::string cd(Session& context, const std::string& path);
 std::string scp(Session& context, const std::string& source,
                 const std::string& destination);
+std::string chown(Session& context, const std::string& owner,
+                  const std::string& path);
+std::string chgrp(Session& context, const std::string& group,
+                  const std::string& path);
 
 /* NETWORK ACTIONS. */
 std::string ssh(Session& context, const std::string& ip);
@@ -26,6 +31,7 @@ std::string nmap(Session& context, const std::string& ip);
 std::string disconnect(Session& context);
 
 /* SYSTEM ACTIONS. */
+std::string get_username(Session& context);
 std::string close_terminal(Session& context);
 
 } /* namespace api */
diff --git a/common/src/lua_processor.cpp b/common/src/lua_processor.cpp
index d74c3ee..d7c3185 100644
--- a/common/src/lua_processor.cpp
+++ b/common/src/lua_processor.cpp
@@ -44,13 +44,17 @@ LuaProcessor::LuaProcessor(Session& context) {
   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("read_file",         &api::read_file);
   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);
+  bettola_api.set_function("chown",             &api::chown);
+  bettola_api.set_function("chgrp",             &api::chgrp);
   bettola_api.set_function("close_terminal",    &api::close_terminal);
   bettola_api.set_function("ssh",               &api::ssh);
   bettola_api.set_function("nmap",              &api::nmap);
   bettola_api.set_function("disconnect",        &api::disconnect);
+  bettola_api.set_function("get_username",      &api::get_username);
 }
 
 LuaProcessor::~LuaProcessor(void) {}
diff --git a/common/src/machine.h b/common/src/machine.h
index ebad545..90e2005 100644
--- a/common/src/machine.h
+++ b/common/src/machine.h
@@ -9,9 +9,10 @@
 
 class Machine {
 public:
-  Machine(uint32_t id, std::string hostname) :
+  Machine(uint32_t id, std::string hostname, uint32_t owner_id = 0) :
       id(id),
       hostname(std::move(hostname)),
+      owner_id(owner_id),
       vfs_root(nullptr),
       is_vfs_a_copy(false) {}
 
@@ -19,6 +20,7 @@ public:
 
   uint32_t id;
   std::string hostname;
+  uint32_t owner_id;
   vfs_node* vfs_root;
   std::map<int, std::string> services;
   bool is_vfs_a_copy; /* Flag for CoW mechanism. */
diff --git a/common/src/machine_manager.cpp b/common/src/machine_manager.cpp
index 2ba4ccb..7efeba3 100644
--- a/common/src/machine_manager.cpp
+++ b/common/src/machine_manager.cpp
@@ -109,8 +109,9 @@ Machine* MachineManager::load_machine(long long machine_id) {
   printf("DEBUG: load_machine called for machine_id: %lld\n", machine_id);
 
   std::string hostname = _db_manager->machines().get_hostname(machine_id);
+  long long owner_id = _db_manager->machines().get_owner_id(machine_id);
 
-  Machine* machine = new Machine(machine_id, hostname);
+  Machine* machine = new Machine(machine_id, hostname, owner_id);
 
   /* Load all VFS nodes for this machine from the database. */
   std::map<long long, vfs_node*> node_map;
diff --git a/common/src/session.cpp b/common/src/session.cpp
index a47a01f..451a42d 100644
--- a/common/src/session.cpp
+++ b/common/src/session.cpp
@@ -1,5 +1,6 @@
 #include <sol/types.hpp>
 #include <sstream>
+#include <vector>
 
 #include "session.h"
 #include "db/database_manager.h"
@@ -149,3 +150,34 @@ std::string Session::read_file(const std::string& path) {
   }
   return "Error: file not found.";
 }
+
+std::string Session::get_username(void) {
+  if(!_home_machine || !_home_machine->vfs_root) {
+    return "unknown";
+  }
+
+  vfs_node* passwd_node = find_node_by_path(_home_machine->vfs_root, "/etc/passwd");
+  if(!passwd_node || passwd_node->type != FILE_NODE) {
+    return "unknown";
+  }
+
+  std::stringstream ss(passwd_node->content);
+  std::string line;
+  uint32_t player_id = _home_machine->owner_id;
+
+  while(std::getline(ss, line)) {
+    std::vector<std::string> parts;
+    std::stringstream line_ss(line);
+    std::string part;
+    while(std::getline(line_ss, part, ':')) {
+      parts.push_back(part);
+    }
+
+    if(parts.size() >= 3) {
+      if(std::to_string(player_id) == parts[2]) {
+        return parts[0]; /* Username. */
+      }
+    }
+  }
+  return "unknown";
+}
diff --git a/common/src/session.h b/common/src/session.h
index ffa5cb7..5ca7b36 100644
--- a/common/src/session.h
+++ b/common/src/session.h
@@ -19,6 +19,8 @@ public:
   std::string write_file(const std::string& path, const std::string& content);
   std::string read_file(const std::string& path);
 
+  std::string get_username(void);
+
   /* Public interface for API functions. */
   vfs_node* get_current_dir(void);
   Machine* get_home_machine(void);