diff --git a/CMakeLists.txt b/CMakeLists.txt
index dd7dbf9..1f9fe34 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.10)
-project(fun VERSION 0.37.32 LANGUAGES C)
+project(fun VERSION 0.37.44 LANGUAGES C)
 
 set(CMAKE_C_STANDARD 99)
 set(CMAKE_C_STANDARD_REQUIRED ON)
@@ -20,7 +20,7 @@ if(NOT DEFINED DEFAULT_LIB_DIR OR DEFAULT_LIB_DIR STREQUAL "")
   else()
     set(_FUN_DEFAULT_LIB_DIR "/usr/share/fun/lib")
   endif()
-  set(DEFAULT_LIB_DIR "${_FUN_DEFAULT_LIB_DIR}" CACHE PATH "Default library directory for Fun stdlib (override with -DDEFAULT_LIB_DIR=...)" FORCE)
+    set(DEFAULT_LIB_DIR "${_FUN_DEFAULT_LIB_DIR}" CACHE PATH "Default library directory for Fun stdlib (override with -DDEFAULT_LIB_DIR=...)" FORCE)
 else()
   set(DEFAULT_LIB_DIR "${DEFAULT_LIB_DIR}" CACHE PATH "Default library directory for Fun stdlib (override with -DDEFAULT_LIB_DIR=...)" FORCE)
 endif()
@@ -30,27 +30,27 @@ endif()
 option(FUN_USE_MUSL "Use musl libc toolchain when available (Linux only)" OFF)
 
 if(FUN_USE_MUSL AND UNIX AND NOT APPLE)
-    # Try to find a musl toolchain wrapper
-    find_program(_FUN_MUSL_CC NAMES musl-gcc musl-clang)
-    if(_FUN_MUSL_CC)
-        message(STATUS "FUN_USE_MUSL=ON: using musl toolchain: ${_FUN_MUSL_CC}")
-        # Force C compiler to musl wrapper before project() so the whole toolchain is configured accordingly
-        set(CMAKE_C_COMPILER "${_FUN_MUSL_CC}" CACHE FILEPATH "C compiler" FORCE)
-        set(FUN_LIBC "musl" CACHE STRING "Selected C library")
-    else()
-        message(WARNING "FUN_USE_MUSL=ON but no musl toolchain (musl-gcc or musl-clang) found. Falling back to default compiler (likely glibc).")
-        set(FUN_LIBC "glibc" CACHE STRING "Selected C library")
-    endif()
-else()
-    # Default remains the system toolchain (typically glibc on Linux)
+  # Try to find a musl toolchain wrapper
+  find_program(_FUN_MUSL_CC NAMES musl-gcc musl-clang)
+  if(_FUN_MUSL_CC)
+    message(STATUS "FUN_USE_MUSL=ON: using musl toolchain: ${_FUN_MUSL_CC}")
+    # Force C compiler to musl wrapper before project() so the whole toolchain is configured accordingly
+    set(CMAKE_C_COMPILER "${_FUN_MUSL_CC}" CACHE FILEPATH "C compiler" FORCE)
+    set(FUN_LIBC "musl" CACHE STRING "Selected C library")
+  else()
+    message(WARNING "FUN_USE_MUSL=ON but no musl toolchain (musl-gcc or musl-clang) found. Falling back to default compiler (likely glibc).")
     set(FUN_LIBC "glibc" CACHE STRING "Selected C library")
+  endif()
+else()
+  # Default remains the system toolchain (typically glibc on Linux)
+  set(FUN_LIBC "glibc" CACHE STRING "Selected C library")
 endif()
 
 # Expose a preprocessor macro indicating selected C library
 if(FUN_LIBC STREQUAL "musl")
-    add_definitions(-DFUN_LIBC_MUSL)
+  add_definitions(-DFUN_LIBC_MUSL)
 else()
-    add_definitions(-DFUN_LIBC_GLIBC)
+  add_definitions(-DFUN_LIBC_GLIBC)
 endif()
 
 # Optional: build statically linked executables
@@ -82,8 +82,8 @@ if(FUN_LINK_STATIC)
 
   # On MSVC, prefer the static runtime
   if(MSVC)
-    foreach(flag_var CMAKE_C_FLAGS CMAKE_C_FLAGS_DEBUG CMAKE_C_FLAGS_RELEASE
-                    CMAKE_C_FLAGS_RELWITHDEBINFO CMAKE_C_FLAGS_MINSIZEREL)
+    foreach(flag_var CMAKE_C_FLAGS CMAKE_C_FLAGS_DEBUG CMAKE_C_FLAGS_RELEASE 
+            CMAKE_C_FLAGS_RELWITHDEBINFO CMAKE_C_FLAGS_MINSIZEREL)
       if(DEFINED ${flag_var})
         string(REPLACE "/MD" "/MT" ${flag_var} "${${flag_var}}")
       endif()
@@ -151,7 +151,7 @@ if(FUN_WITH_TCLTK)
 endif()
 # Ensure trailing slash
 if(NOT DEFAULT_LIB_DIR MATCHES "/$")
-    set(DEFAULT_LIB_DIR "${DEFAULT_LIB_DIR}/")
+  set(DEFAULT_LIB_DIR "${DEFAULT_LIB_DIR}/")
 endif()
 
 # Optional SQLite support
@@ -184,14 +184,14 @@ option(FUN_WITH_PCSC "Enable PCSC (pcsclite) support" OFF)
 set(PCSC_LINK_LIBS "")
 set(PCSC_INCLUDE_DIRS "")
 if(FUN_WITH_PCSC)
-    message(STATUS "Building with PCSC support")
-    add_definitions(-DFUN_WITH_PCSC)
-    if(APPLE)
-        list(APPEND PCSC_LINK_LIBS "-framework PCSC")
-    else()
-        list(APPEND PCSC_INCLUDE_DIRS "/usr/include/PCSC")
-        list(APPEND PCSC_LINK_LIBS pcsclite)
-    endif()
+  message(STATUS "Building with PCSC support")
+  add_definitions(-DFUN_WITH_PCSC)
+  if(APPLE)
+    list(APPEND PCSC_LINK_LIBS "-framework PCSC")
+  else()
+    list(APPEND PCSC_INCLUDE_DIRS "/usr/include/PCSC")
+    list(APPEND PCSC_LINK_LIBS pcsclite)
+  endif()
 endif()
 
 # Optional JSON (json-c) support
@@ -269,9 +269,9 @@ if(FUN_WITH_XML2)
         list(APPEND LIBXML2_INCLUDE_DIRS "/usr/include/libxml2")
         include_directories(${LIBXML2_INCLUDE_DIRS})
       endif()
-    else()
-      message(FATAL_ERROR "libxml2 not found. Install libxml2 (dev headers) or disable FUN_WITH_XML2.")
-    endif()
+  else()
+    message(FATAL_ERROR "libxml2 not found. Install libxml2 (dev headers) or disable FUN_WITH_XML2.")
+  endif()
   endif()
   # As a robust fallback, add standard system include path for libxml2 if present
   if(EXISTS "/usr/include/libxml2")
@@ -365,21 +365,21 @@ endif()
 
 # Core VM/library sources
 add_library(fun_core
-        src/bytecode.c
-        src/parser.c
-        src/value.c
-        src/vm.c
+  src/bytecode.c
+  src/parser.c
+  src/value.c
+  src/vm.c
 )
 
 target_include_directories(fun_core PUBLIC
-        ${CMAKE_CURRENT_SOURCE_DIR}/src
+  ${CMAKE_CURRENT_SOURCE_DIR}/src
 )
 
 # Apply options to core
 if(FUN_DEBUG)
-    message(STATUS "FUN_DEBUG enabled: building with verbose debug logging")
-    target_compile_definitions(fun_core PUBLIC FUN_VERSION="${PROJECT_VERSION}")
-    target_compile_definitions(fun_core PUBLIC FUN_DEBUG=1)
+  message(STATUS "FUN_DEBUG enabled: building with verbose debug logging")
+  target_compile_definitions(fun_core PUBLIC FUN_VERSION="${PROJECT_VERSION}")
+  target_compile_definitions(fun_core PUBLIC FUN_DEBUG=1)
 endif()
 
 # Provide default stdlib directory to the runtime
@@ -468,10 +468,16 @@ if(Threads_FOUND)
   target_link_libraries(fun_core PUBLIC Threads::Threads)
 endif()
 
+# Link libm for C99 math functions if available
+find_library(M_LIB m)
+if(M_LIB)
+  target_link_libraries(fun_core PUBLIC ${M_LIB})
+endif()
+
 # Interpreter /usr/bin/fun
 option(FUN_WITH_REPL "Enable interactive REPL in the fun CLI" OFF)
 add_executable(fun
-        src/fun.c
+  src/fun.c
 )
 # Provide version string to the CLI
 if(FUN_WITH_REPL)
@@ -483,12 +489,12 @@ target_link_libraries(fun PRIVATE fun_core)
 
 # Internal test programs
 add_executable(fun_test
-        src/fun_test.c
+  src/fun_test.c
 )
 target_link_libraries(fun_test PRIVATE fun_core)
 
 add_executable(test_opcodes
-        src/test_opcodes.c
+  src/test_opcodes.c
 )
 target_link_libraries(test_opcodes PRIVATE fun_core)
 
@@ -511,11 +517,11 @@ set(FUN_RUN_SCRIPT "" CACHE STRING "Script to run with the 'run' target, e.g. -D
 
 if(FUN_WITH_REPL)
   add_custom_target(repl
-    COMMAND $<TARGET_FILE:fun>
-    DEPENDS fun
-    USES_TERMINAL
-    COMMENT "Run Fun REPL"
-  )
+  COMMAND $<TARGET_FILE:fun>
+  DEPENDS fun
+  USES_TERMINAL
+  COMMENT "Run Fun REPL"
+)
 endif()
 
 add_custom_target(run
@@ -555,14 +561,14 @@ add_custom_target(ops-quiet
 )
 
 add_custom_target(examples
-  COMMAND ${CMAKE_COMMAND} -E env FUN_LIB_DIR="${FUN_LIB}" ${CMAKE_SOURCE_DIR}/scripts/run_examples.sh
+  COMMAND ${CMAKE_COMMAND} -E env FUN_LIB_DIR="${FUN_LIB}" FUN_WITH_INI=$<IF:$<BOOL:${FUN_WITH_INI}>,1,0> ${CMAKE_SOURCE_DIR}/scripts/run_examples.sh
   DEPENDS fun
   USES_TERMINAL
   COMMENT "Build and run all examples"
 )
 
 add_custom_target(run-examples
-  COMMAND ${CMAKE_COMMAND} -E env FUN_LIB_DIR="${FUN_LIB}" ${CMAKE_SOURCE_DIR}/scripts/run_examples.sh
+  COMMAND ${CMAKE_COMMAND} -E env FUN_LIB_DIR="${FUN_LIB}" FUN_WITH_INI=$<IF:$<BOOL:${FUN_WITH_INI}>,1,0> ${CMAKE_SOURCE_DIR}/scripts/run_examples.sh
   DEPENDS fun
   USES_TERMINAL
   COMMENT "Build and run all examples"
@@ -570,20 +576,20 @@ add_custom_target(run-examples
 
 # Clean and distclean
 add_custom_target(fun_clean
-        COMMAND ${CMAKE_COMMAND} --build ${CMAKE_BINARY_DIR} --target clean
-        COMMENT "Clean build outputs (objects, binaries) in the build directory"
+  COMMAND ${CMAKE_COMMAND} --build ${CMAKE_BINARY_DIR} --target clean
+  COMMENT "Clean build outputs (objects, binaries) in the build directory"
 )
 add_custom_target(distclean
-        COMMAND ${CMAKE_COMMAND} --build ${CMAKE_BINARY_DIR} --target clean
-        COMMAND ${CMAKE_COMMAND} -E rm -rf
-        ${CMAKE_BINARY_DIR}/CMakeCache.txt
-        ${CMAKE_BINARY_DIR}/CMakeFiles
-        ${CMAKE_BINARY_DIR}/cmake_install.cmake
-        ${CMAKE_BINARY_DIR}/install_manifest.txt
-        ${CMAKE_BINARY_DIR}/Makefile
-        ${CMAKE_BINARY_DIR}/*.ninja
-        ${CMAKE_BINARY_DIR}/.ninja_*
-        COMMENT "Remove build outputs and CMake-generated files (reconfigure needed)"
+  COMMAND ${CMAKE_COMMAND} --build ${CMAKE_BINARY_DIR} --target clean
+  COMMAND ${CMAKE_COMMAND} -E rm -rf
+  ${CMAKE_BINARY_DIR}/CMakeCache.txt
+  ${CMAKE_BINARY_DIR}/CMakeFiles
+  ${CMAKE_BINARY_DIR}/cmake_install.cmake
+  ${CMAKE_BINARY_DIR}/install_manifest.txt
+  ${CMAKE_BINARY_DIR}/Makefile
+  ${CMAKE_BINARY_DIR}/*.ninja
+  ${CMAKE_BINARY_DIR}/.ninja_*
+  COMMENT "Remove build outputs and CMake-generated files (reconfigure needed)"
 )
 
 # Robust uninstall support as a function (uses install_manifest*.txt)
@@ -615,14 +621,14 @@ list(APPEND _candidates
 set(_manifest_file \"\")
 foreach(_cand IN LISTS _candidates)
   if(EXISTS \"\${_cand}\")
-    set(_manifest_file \"\${_cand}\")
-    break()
+  set(_manifest_file \"\${_cand}\")
+  break()
   endif()
 endforeach()
 
 if(NOT _manifest_file)
   message(FATAL_ERROR
-    \"Cannot find install manifest. Tried: \${_candidates}.
+  \"Cannot find install manifest. Tried: \${_candidates}.
 If you installed from a different build directory, run uninstall from that build directory (where install_manifest*.txt resides).\")
 endif()
 
@@ -632,21 +638,21 @@ set(_removed 0)
 set(_dirs \"\")
 foreach(_file IN LISTS _files)
   if(_file STREQUAL \"\")
-    continue()
+  continue()
   endif()
   if(EXISTS \"\${_file}\" OR IS_SYMLINK \"\${_file}\")
-    message(STATUS \"Uninstalling: \${_file}\")
-    file(REMOVE \"\${_file}\")
-    # If the file still exists after attempting to remove it, fail with an explicit error
-    if(EXISTS \"\${_file}\" OR IS_SYMLINK \"\${_file}\")
-      message(FATAL_ERROR \"Failed to remove: \${_file}. Try running the uninstall target with sudo if it is a system install.\")
-    endif()
-    # Track the containing directory for potential cleanup
-    get_filename_component(_dir \"\${_file}\" DIRECTORY)
-    list(APPEND _dirs \"\${_dir}\")
-    math(EXPR _removed \"\${_removed}+1\")
+  message(STATUS \"Uninstalling: \${_file}\")
+  file(REMOVE \"\${_file}\")
+  # If the file still exists after attempting to remove it, fail with an explicit error
+  if(EXISTS \"\${_file}\" OR IS_SYMLINK \"\${_file}\")
+    message(FATAL_ERROR \"Failed to remove: \${_file}. Try running the uninstall target with sudo if it is a system install.\")
+  endif()
+  # Track the containing directory for potential cleanup
+  get_filename_component(_dir \"\${_file}\" DIRECTORY)
+  list(APPEND _dirs \"\${_dir}\")
+  math(EXPR _removed \"\${_removed}+1\")
   else()
-    message(STATUS \"Skipping (not found): \${_file}\")
+  message(STATUS \"Skipping (not found): \${_file}\")
   endif()
 endforeach()
 
@@ -659,14 +665,14 @@ set(_all_dirs \"\")
 foreach(_d IN LISTS _dirs)
   set(_p \"\${_d}\")
   while(NOT \"\${_p}\" STREQUAL \"\" AND NOT \"\${_p}\" STREQUAL \"/\")
+  list(APPEND _all_dirs \"\${_p}\")
+  get_filename_component(_p \"\${_p}\" DIRECTORY)
+  # Stop collecting parents once we reach a safe root or the filesystem root
+  list(FIND _safe_roots \"\${_p}\" _root_idx)
+  if(_root_idx GREATER -1)
     list(APPEND _all_dirs \"\${_p}\")
-    get_filename_component(_p \"\${_p}\" DIRECTORY)
-    # Stop collecting parents once we reach a safe root or the filesystem root
-    list(FIND _safe_roots \"\${_p}\" _root_idx)
-    if(_root_idx GREATER -1)
-      list(APPEND _all_dirs \"\${_p}\")
-      break()
-    endif()
+    break()
+  endif()
   endwhile()
 endforeach()
 
@@ -679,38 +685,38 @@ set(_pass 0)
 while(TRUE)
   set(_pass_removed 0)
   foreach(_dir IN LISTS _all_dirs)
-    if(EXISTS \"\${_dir}\" AND IS_DIRECTORY \"\${_dir}\")
-      # Only act on directories within safe roots
-      set(_allowed FALSE)
-      foreach(_root IN LISTS _safe_roots)
-        if(\"\${_dir}\" MATCHES \"^\${_root}(/|\$)\")
-          set(_allowed TRUE)
-          break()
-        endif()
-      endforeach()
-      if(NOT _allowed)
-        # e.g. /usr/bin — do not remove
-        continue()
-      endif()
-
-      # Remove only if empty (do not recurse unrelated content)
-      file(GLOB _dir_contents LIST_DIRECTORIES true \"\${_dir}/*\")
-      list(LENGTH _dir_contents _dir_len)
-      if(_dir_len EQUAL 0)
-        message(STATUS \"Removing empty directory: \${_dir}\")
-        file(REMOVE_RECURSE \"\${_dir}\")
-        if(IS_DIRECTORY \"\${_dir}\")
-          message(FATAL_ERROR \"Failed to remove directory: \${_dir}. Try running the uninstall target with sudo if it is a system install.\")
-        endif()
-        math(EXPR _removed_dirs \"\${_removed_dirs}+1\")
-        math(EXPR _pass_removed \"\${_pass_removed}+1\")
-      endif()
+  if(EXISTS \"\${_dir}\" AND IS_DIRECTORY \"\${_dir}\")
+    # Only act on directories within safe roots
+    set(_allowed FALSE)
+    foreach(_root IN LISTS _safe_roots)
+    if(\"\${_dir}\" MATCHES \"^\${_root}(/|\$)\")
+      set(_allowed TRUE)
+      break()
     endif()
+    endforeach()
+    if(NOT _allowed)
+    # e.g. /usr/bin — do not remove
+    continue()
+    endif()
+
+    # Remove only if empty (do not recurse unrelated content)
+    file(GLOB _dir_contents LIST_DIRECTORIES true \"\${_dir}/*\")
+    list(LENGTH _dir_contents _dir_len)
+    if(_dir_len EQUAL 0)
+    message(STATUS \"Removing empty directory: \${_dir}\")
+    file(REMOVE_RECURSE \"\${_dir}\")
+    if(IS_DIRECTORY \"\${_dir}\")
+      message(FATAL_ERROR \"Failed to remove directory: \${_dir}. Try running the uninstall target with sudo if it is a system install.\")
+    endif()
+    math(EXPR _removed_dirs \"\${_removed_dirs}+1\")
+    math(EXPR _pass_removed \"\${_pass_removed}+1\")
+    endif()
+  endif()
   endforeach()
 
   math(EXPR _pass \"\${_pass}+1\")
   if(_pass_removed EQUAL 0 OR _pass GREATER 5)
-    break()
+  break()
   endif()
 endwhile()
 
@@ -720,13 +726,13 @@ message(STATUS \"Uninstall finished. Removed \${_removed} files and \${_removed_
   # Expose an 'uninstall' build target (run with sudo if system locations were used)
   add_custom_target(uninstall
     COMMAND ${CMAKE_COMMAND}
-            -D MANIFEST="${CMAKE_BINARY_DIR}/install_manifest.txt"
-            -D CMAKE_BINARY_DIR="${CMAKE_BINARY_DIR}"
-            -D CMAKE_SOURCE_DIR="${CMAKE_SOURCE_DIR}"
-            -P "${_FUN_UNINSTALL_SCRIPT}"
+      -D MANIFEST="${CMAKE_BINARY_DIR}/install_manifest.txt"
+      -D CMAKE_BINARY_DIR="${CMAKE_BINARY_DIR}"
+      -D CMAKE_SOURCE_DIR="${CMAKE_SOURCE_DIR}"
+      -P "${_FUN_UNINSTALL_SCRIPT}"
     USES_TERMINAL
     COMMENT "Uninstall files installed by this project (use sudo if needed)"
-  )
+)
 endfunction()
 
 # Define the uninstall target
@@ -735,21 +741,25 @@ fun_add_uninstall_target()
 # Install rules
 # Binary
 install(TARGETS fun
-        RUNTIME DESTINATION /usr/bin)
+  RUNTIME DESTINATION /usr/bin
+)
 
 # Libs
 install(DIRECTORY lib/
-        DESTINATION /usr/share/fun/lib
-        FILES_MATCHING PATTERN "*.fun")
+  DESTINATION /usr/share/fun/lib
+  FILES_MATCHING PATTERN "*.fun"
+)
 
 # Optionally install example scripts
 option(FUN_INSTALL_EXAMPLES "Install example .fun scripts" ON)
 if(FUN_INSTALL_EXAMPLES)
-    install(DIRECTORY examples/
-            DESTINATION /usr/share/fun/examples
-            FILES_MATCHING PATTERN "*.fun")
+  install(DIRECTORY examples/ 
+    DESTINATION /usr/share/fun/examples
+    FILES_MATCHING PATTERN "*.fun"
+  )
 endif()
 
 # - Docs
 install(FILES README.md LICENSE
-        DESTINATION /usr/share/doc/fun)
+  DESTINATION /usr/share/doc/fun
+)
diff --git a/examples/cli_argv_dump.fun b/examples/cli_argv_dump.fun
new file mode 100755
index 0000000..0b2c2e9
--- /dev/null
+++ b/examples/cli_argv_dump.fun
@@ -0,0 +1,32 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2025-12-30
+ */
+
+// Demonstrates accessing raw script arguments via lib/cli.fun
+// Usage:
+//   FUN_LIB_DIR="$(pwd)/lib" ./build/fun ./examples/cli_argv_dump.fun -f --force=42 foo bar
+
+#include <cli.fun>
+
+args = argv()
+
+print(join(["FUN_ARGC=", env("FUN_ARGC")], ""))
+print(join(["FUN_ARGS='", env("FUN_ARGS"), "'"], ""))
+print("Raw argv array:")
+print(args)
+
+/* Expected output:
+FUN_ARGC=3
+FUN_ARGS='-f --force --force=42'
+Raw argv array:
+[-f, --force, --force=42
+*/
diff --git a/examples/cli_parse_example.fun b/examples/cli_parse_example.fun
new file mode 100755
index 0000000..be40b40
--- /dev/null
+++ b/examples/cli_parse_example.fun
@@ -0,0 +1,48 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2025-12-30
+ */
+
+// Demonstrates parsing flags like -f, --force, --force=42 and positionals
+// Usage examples:
+//   FUN_LIB_DIR="$(pwd)/lib" ./build/fun ./examples/cli_parse_example.fun -f foo
+//   FUN_LIB_DIR="$(pwd)/lib" ./build/fun ./examples/cli_parse_example.fun --force bar
+//   FUN_LIB_DIR="$(pwd)/lib" ./build/fun ./examples/cli_parse_example.fun --force=42 alpha beta
+//   FUN_LIB_DIR="$(pwd)/lib" ./build/fun ./examples/cli_parse_example.fun -abc x y
+
+#include <cli.fun>
+
+args = argv()
+parsed = parse_args(args)
+flags = parsed["flags"]
+pos = parsed["positionals"]
+
+if (flags["f"] == 1 || flags["force"] == 1)
+  print("Force enabled")
+
+// No hasKey() builtin available here; check via keys()+contains()
+flag_keys = keys(flags)
+if (contains(flag_keys, "force") && typeof(flags["force"]) == "string")
+  print(join(["Force value=", flags["force"]], ""))
+
+print("Flags map:")
+print(flags)
+print("Positionals:")
+print(pos)
+
+/* Expected output (FUN_LIB_DIR="$(pwd)/lib" ./build/fun ./examples/cli_parse_example.fun --force bar xx x x --for=xxx --h=1):
+1
+Force enabled
+Flags map:
+{"force": 1, "for": xxx, "h": 1}
+Positionals:
+[bar, xx, x, x]
+*/
diff --git a/examples/data/complex.ini b/examples/data/complex.ini
index 18084af..2d73052 100644
--- a/examples/data/complex.ini
+++ b/examples/data/complex.ini
@@ -1,32 +1,29 @@
+[auth]
+user = "hanez"
+token = "abcd1234"
 
 [app]
-name                           = "FunApp"
-version                        = "1.2.3"
-debug                          = "1"
-
+name = "FunApp"
+version = "1.2.3"
+debug = "1"
 
 [database]
-host                           = "localhost"
-port                           = "5432"
-user                           = "fun"
-pass                           = "secret"
-pool_size                      = "8"
-timeout                        = "2.5"
-
+host = "localhost"
+port = "5432"
+user = "fun"
+pass = "secret"
+pool_size = "8"
+timeout = "2.5"
 
 [network]
-ssl                            = "yes"
-retries                        = "3"
-base_url                       = "https://api.example.com"
-
+ssl = "yes"
+retries = "3"
+base_url = "https://api.example.com"
 
 [features]
-feature_x                      = "on"
-feature_y                      = "off"
-
+feature_x = "on"
+feature_y = "off"
 
 [paths]
-data_dir                       = "./data"
-log_file                       = "./logs/app.log"
-
-
+data_dir = "./data"
+log_file = "./logs/app.log"
diff --git a/examples/data/htdocs/info.fun b/examples/data/htdocs/info.fun
index 65e64cb..eca1076 100644
--- a/examples/data/htdocs/info.fun
+++ b/examples/data/htdocs/info.fun
@@ -16,7 +16,10 @@ print("<h1>Fun Environment Information</h1>")
 print("<p><strong>Current Path:</strong> " + env("PATH") + "</p>")
 print("<p><strong>Current User:</strong> " + env("USER") + "</p>")
 print("<p><strong>Time:</strong> " + date_format(time_now_ms(), "%Y-%m-%d %H:%M:%S") + "</p>")
-print("<p><strong>Version:</strong> " + to_string(fun_version()) + "</p>")
+print("<p><strong>Local Version:</strong> " + to_string(fun_version()) + "</p>")
+res = proc_run("fun -V")
+installed_version = res["out"]
+print("<p><strong>Installed Version:</strong> " + to_string(substr(installed_version, 4, len(installed_version)-2)) + "</p>")
 print("<h2>Full Environment:</h2>")
 print("<ul>")
 all_env = env_all()
diff --git a/examples/env_all.fun b/examples/env_all.fun
old mode 100644
new mode 100755
diff --git a/examples/extra/http_server_test.fun b/examples/extra/http_server_test.fun
index ad3ab64..4a35ae9 100755
--- a/examples/extra/http_server_test.fun
+++ b/examples/extra/http_server_test.fun
@@ -1,3 +1,16 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2025-12-28
+ */
+
 #include <io/socket.fun>
 
 c = TcpClient()
@@ -9,7 +22,6 @@ if (c.connect("127.0.0.1", 8080))
     resp = c.recv_all(4096)
     print("GET Response contains foo=bar: " + to_string(find(resp, "foo = bar") >= 0))
     print("GET Response contains baz=qux: " + to_string(find(resp, "baz = qux") >= 0))
-    
     c.close()
 else
     print("Failed to connect to server")
diff --git a/examples/ini_complex.fun b/examples/ini_complex.fun
index 5c7d2b1..2707983 100755
--- a/examples/ini_complex.fun
+++ b/examples/ini_complex.fun
@@ -91,10 +91,9 @@ else
   retries=3
   base_url=https://api.example.com
 [features]
-  feature_x=0
+  feature_x=1
   feature_y=0
 [paths]
   data_dir=./data
   log_file=./logs/app.log
 */
-
diff --git a/examples/ini_demo.fun b/examples/ini_demo.fun
index 40f9cc4..7895584 100755
--- a/examples/ini_demo.fun
+++ b/examples/ini_demo.fun
@@ -19,7 +19,7 @@ if h == 0
   print("Failed to load " + path)
 else
   u = ini_get_string(h, "auth", "user", "guest")
-  r = ini_get_int(h, "network", "retries", 3)
+  r = ini_get_int(h, "network", "retries", 5)
   s = ini_get_bool(h, "network", "ssl", 0)
   print("user=" + u)
   print("retries=" + to_string(r))
@@ -33,4 +33,11 @@ else
 user=����U
 retries=3
 ssl=1
+
+I wonder about the user= value when the default value is used!
+
+It should look like:
+user=guest
+retries=3
+ssl=1
 */
diff --git a/examples/ini_diag.fun b/examples/ini_diag.fun
new file mode 100644
index 0000000..f360cd9
--- /dev/null
+++ b/examples/ini_diag.fun
@@ -0,0 +1,50 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-02
+ */
+
+// Minimal diagnostic for INI lookups
+
+path = "./examples/data/complex.ini"
+h = ini_load(path)
+print("h=" + to_string(h))
+if h == 0
+  print("Failed to load: " + path)
+else
+  print("[try app:name]")
+  v1 = ini_get_string(h, "app", "name", "<def>")
+  print("app:name => " + v1)
+
+  print("[try app:version]")
+  v2 = ini_get_string(h, "app", "version", "<def>")
+  print("app:version => " + v2)
+
+  print("[try database:port]")
+  v3 = ini_get_int(h, "database", "port", -1)
+  print("database:port => " + to_string(v3))
+
+  print("[try network:ssl]")
+  v4 = ini_get_bool(h, "network", "ssl", -9)
+  print("network:ssl => " + to_string(v4))
+
+  ini_free(h)
+
+/* Expected output:
+h=1
+[try app:name]
+app:name => FunApp
+[try app:version]
+app:version => 1.2.3
+[try database:port]
+database:port => 5432
+[try network:ssl]
+network:ssl => 1
+*/
diff --git a/examples/input_hidden_example.fun b/examples/input_hidden_example.fun
new file mode 100755
index 0000000..770f69f
--- /dev/null
+++ b/examples/input_hidden_example.fun
@@ -0,0 +1,29 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Example: Demonstrate hidden input (no echo) for passwords.
+ *
+ * Added: 2026-01-02
+ */
+
+#include <io/console.fun>
+
+print("=== input_hidden() example ===")
+
+c = Console()
+
+username = c.ask("Username")
+password = c.ask_hidden("Password")
+
+// Do not print the password; just show the username
+print(join(["Hello, ", username, "!"], ""))
+
+/* Expected output:
+Username: hanez
+Password:
+=== input_hidden() example ===
+Hello, hanez!
+*/
diff --git a/examples/input_hidden_pam_auth.fun b/examples/input_hidden_pam_auth.fun
new file mode 100755
index 0000000..56d5fb7
--- /dev/null
+++ b/examples/input_hidden_pam_auth.fun
@@ -0,0 +1,45 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Example: Demonstrate hidden input (no echo) for passwords using
+ * /usr/bin/chkpwd from https://git.xw3.org/hanez/chkusr for PAM authetication.
+ *
+ * Added: 2026-01-02
+ */
+
+#include <io/console.fun>
+
+print("=== input_hidden() example with PAM authentication ===")
+
+c = Console()
+
+username = c.ask("Username")
+password = c.ask_hidden("Password")
+
+// Do not print the password; just show the username
+print(join(["Hello, ", username, "!"], ""))
+
+res = proc_run("chkpwd -u " + username + " -p " + password)
+content = res["out"]
+if (res["code"] == 0)
+  print("Login success!")
+else
+  print("Login failed!")
+
+/* Possible output:
+Username: hanez
+Password:
+=== input_hidden() example with PAM authentication ===
+Hello, hanez!
+Login success!
+
+Or:
+Username: hanez
+Password: 
+=== input_hidden() example with PAM authentication ===
+Hello, hanez!
+Login failed!
+*/
diff --git a/examples/math_ceil.fun b/examples/math_ceil.fun
new file mode 100644
index 0000000..5c2ef16
--- /dev/null
+++ b/examples/math_ceil.fun
@@ -0,0 +1,36 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+// Demo of C99-like ceil(x)
+
+print("=== math ceil demo start ===")
+
+print("ceil(3.2) -> " + to_string(ceil(3.2)))       // 4
+print("ceil(3.0) -> " + to_string(ceil(3.0)))       // 3
+print("ceil(-3.2) -> " + to_string(ceil(-3.2)))     // -3
+print("ceil(-3.0) -> " + to_string(ceil(-3.0)))     // -3
+print("ceil(0.5) -> " + to_string(ceil(0.5)))       // 1
+print("ceil(-0.5) -> " + to_string(ceil(-0.5)))     // 0
+
+print("=== math ceil demo end ===")
+
+/* Expected output (values):
+=== math ceil demo start ===
+ceil(3.2) -> 4
+ceil(3.0) -> 3
+ceil(-3.2) -> -3
+ceil(-3.0) -> -3
+ceil(0.5) -> 1
+ceil(-0.5) -> 0
+=== math ceil demo end ===
+*/
diff --git a/examples/math_cos.fun b/examples/math_cos.fun
new file mode 100644
index 0000000..f498126
--- /dev/null
+++ b/examples/math_cos.fun
@@ -0,0 +1,30 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+// Demo of cos(x)
+
+print("=== math cos demo start ===")
+
+print("cos(0) -> " + to_string(cos(0)))
+print("cos(3.14159265359) ~ pi -> " + to_string(cos(3.14159265359)))
+print("cos(1.57079632679) ~ pi/2 -> " + to_string(cos(1.57079632679)))
+
+print("=== math cos demo end ===")
+
+/* Expected output (approximate):
+=== math cos demo start ===
+cos(0) -> 1
+cos(3.14159265359) ~ pi -> -1
+cos(1.57079632679) ~ pi/2 -> 0
+=== math cos demo end ===
+*/
diff --git a/examples/math_exp_log.fun b/examples/math_exp_log.fun
new file mode 100644
index 0000000..5be06d2
--- /dev/null
+++ b/examples/math_exp_log.fun
@@ -0,0 +1,34 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+// Demo of exp(x), log(x), log10(x)
+
+print("=== math exp/log demo start ===")
+
+print("exp(0) -> " + to_string(exp(0)))
+print("log(1) -> " + to_string(log(1)))
+print("log10(1) -> " + to_string(log10(1)))
+print("exp(1) -> " + to_string(exp(1)))
+print("log(2.71828182846) ~ ln(e) -> " + to_string(log(2.71828182846)))
+
+print("=== math exp/log demo end ===")
+
+/* Expected output (approximate):
+=== math exp/log demo start ===
+exp(0) -> 1
+log(1) -> 0
+log10(1) -> 0
+exp(1) -> 2.718281828...
+log(2.71828182846) ~ ln(e) -> 1
+=== math exp/log demo end ===
+*/
diff --git a/examples/math_floor.fun b/examples/math_floor.fun
new file mode 100644
index 0000000..94783c7
--- /dev/null
+++ b/examples/math_floor.fun
@@ -0,0 +1,36 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+// Demo of C99-like floor(x)
+
+print("=== math floor demo start ===")
+
+print("floor(3.7) -> " + to_string(floor(3.7)))     // 3
+print("floor(3.0) -> " + to_string(floor(3.0)))     // 3
+print("floor(-3.2) -> " + to_string(floor(-3.2)))   // -4
+print("floor(-3.0) -> " + to_string(floor(-3.0)))   // -3
+print("floor(0.5) -> " + to_string(floor(0.5)))     // 0
+print("floor(-0.5) -> " + to_string(floor(-0.5)))   // -1
+
+print("=== math floor demo end ===")
+
+/* Expected output (values):
+=== math floor demo start ===
+floor(3.7) -> 3
+floor(3.0) -> 3
+floor(-3.2) -> -4
+floor(-3.0) -> -3
+floor(0.5) -> 0
+floor(-0.5) -> -1
+=== math floor demo end ===
+*/
diff --git a/examples/math_fmin_fmax.fun b/examples/math_fmin_fmax.fun
new file mode 100644
index 0000000..2b1a49d
--- /dev/null
+++ b/examples/math_fmin_fmax.fun
@@ -0,0 +1,32 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+// Demo of fmin(x,y) / fmax(x,y) — float-aware min/max with C99 NaN handling
+
+print("=== math fmin/fmax demo start ===")
+
+print("fmin(3.2, 4) -> " + to_string(fmin(3.2, 4)))   // 3.2
+print("fmax(3.2, 4) -> " + to_string(fmax(3.2, 4)))   // 4
+print("fmin(-5, -2.5) -> " + to_string(fmin(-5, -2.5))) // -5
+print("fmax(-5, -2.5) -> " + to_string(fmax(-5, -2.5))) // -2.5
+
+print("=== math fmin/fmax demo end ===")
+
+/* Expected output:
+=== math fmin/fmax demo start ===
+fmin(3.2, 4) -> 3.2000000000000002
+fmax(3.2, 4) -> 4
+fmin(-5, -2.5) -> -5
+fmax(-5, -2.5) -> -2.5
+=== math fmin/fmax demo end ===
+*/
diff --git a/examples/math_gcd_lcm.fun b/examples/math_gcd_lcm.fun
new file mode 100644
index 0000000..4f0fbab
--- /dev/null
+++ b/examples/math_gcd_lcm.fun
@@ -0,0 +1,35 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+print("=== math gcd/lcm demo start ===")
+
+print("gcd(48,18) -> " + to_string(gcd(48,18)))   // 6
+print("gcd(0,5) -> " + to_string(gcd(0,5)))       // 5
+print("gcd(-21,6) -> " + to_string(gcd(-21,6)))  // 3
+
+print("lcm(21,6) -> " + to_string(lcm(21,6)))     // 42
+print("lcm(0,5) -> " + to_string(lcm(0,5)))       // 0
+print("lcm(-4,6) -> " + to_string(lcm(-4,6)))     // 12
+
+print("=== math gcd/lcm demo end ===")
+
+/* Expected output (values):
+=== math gcd/lcm demo start ===
+gcd(48,18) -> 6
+gcd(0,5) -> 5
+gcd(-21,6) -> 3
+lcm(21,6) -> 42
+lcm(0,5) -> 0
+lcm(-4,6) -> 12
+=== math gcd/lcm demo end ===
+*/
diff --git a/examples/math_isqrt.fun b/examples/math_isqrt.fun
new file mode 100644
index 0000000..e232444
--- /dev/null
+++ b/examples/math_isqrt.fun
@@ -0,0 +1,38 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+print("=== math isqrt demo start ===")
+
+print("isqrt(-4) -> " + to_string(isqrt(-4)))    // 0 (non-negative only)
+print("isqrt(0) -> " + to_string(isqrt(0)))      // 0
+print("isqrt(1) -> " + to_string(isqrt(1)))      // 1
+print("isqrt(2) -> " + to_string(isqrt(2)))      // 1
+print("isqrt(3) -> " + to_string(isqrt(3)))      // 1
+print("isqrt(4) -> " + to_string(isqrt(4)))      // 2
+print("isqrt(15) -> " + to_string(isqrt(15)))    // 3
+print("isqrt(16) -> " + to_string(isqrt(16)))    // 4
+
+print("=== math isqrt demo end ===")
+
+/* Expected output (values):
+=== math isqrt demo start ===
+isqrt(-4) -> 0
+isqrt(0) -> 0
+isqrt(1) -> 1
+isqrt(2) -> 1
+isqrt(3) -> 1
+isqrt(4) -> 2
+isqrt(15) -> 3
+isqrt(16) -> 4
+=== math isqrt demo end ===
+*/
diff --git a/examples/math_round.fun b/examples/math_round.fun
new file mode 100644
index 0000000..0c2117c
--- /dev/null
+++ b/examples/math_round.fun
@@ -0,0 +1,36 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+// Demo of C99-like round(x) — half away from zero
+
+print("=== math round demo start ===")
+
+print("round(3.2) -> " + to_string(round(3.2)))     // 3
+print("round(3.5) -> " + to_string(round(3.5)))     // 4
+print("round(3.8) -> " + to_string(round(3.8)))     // 4
+print("round(-3.2) -> " + to_string(round(-3.2)))   // -3
+print("round(-3.5) -> " + to_string(round(-3.5)))   // -4
+print("round(-3.8) -> " + to_string(round(-3.8)))   // -4
+
+print("=== math round demo end ===")
+
+/* Expected output (values):
+=== math round demo start ===
+round(3.2) -> 3
+round(3.5) -> 4
+round(3.8) -> 4
+round(-3.2) -> -3
+round(-3.5) -> -4
+round(-3.8) -> -4
+=== math round demo end ===
+*/
diff --git a/examples/math_sign.fun b/examples/math_sign.fun
new file mode 100644
index 0000000..9fdfd6c
--- /dev/null
+++ b/examples/math_sign.fun
@@ -0,0 +1,32 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+print("=== math sign demo start ===")
+
+print("sign(-5) -> " + to_string(sign(-5)))     // -1
+print("sign(0) -> " + to_string(sign(0)))       // 0
+print("sign(7) -> " + to_string(sign(7)))       // 1
+print("sign(-0.0) -> " + to_string(sign(-0.0))) // 0
+print("sign(3.14) -> " + to_string(sign(3.14))) // 1
+
+print("=== math sign demo end ===")
+
+/* Expected output (values):
+=== math sign demo start ===
+sign(-5) -> -1
+sign(0) -> 0
+sign(7) -> 1
+sign(-0.0) -> 0
+sign(3.14) -> 1
+=== math sign demo end ===
+*/
diff --git a/examples/math_sin.fun b/examples/math_sin.fun
new file mode 100644
index 0000000..193881b
--- /dev/null
+++ b/examples/math_sin.fun
@@ -0,0 +1,30 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+// Demo of sin(x)
+
+print("=== math sin demo start ===")
+
+print("sin(0) -> " + to_string(sin(0)))
+print("sin(1.57079632679) ~ pi/2 -> " + to_string(sin(1.57079632679)))
+print("sin(-1.57079632679) -> " + to_string(sin(-1.57079632679)))
+
+print("=== math sin demo end ===")
+
+/* Expected output (approximate):
+=== math sin demo start ===
+sin(0) -> 0
+sin(1.57079632679) ~ pi/2 -> 1
+sin(-1.57079632679) -> -1
+=== math sin demo end ===
+*/
diff --git a/examples/math_sqrt.fun b/examples/math_sqrt.fun
new file mode 100644
index 0000000..6052981
--- /dev/null
+++ b/examples/math_sqrt.fun
@@ -0,0 +1,32 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+// Demo of sqrt(x)
+
+print("=== math sqrt demo start ===")
+
+print("sqrt(0) -> " + to_string(sqrt(0)))
+print("sqrt(9) -> " + to_string(sqrt(9)))
+print("sqrt(2) -> " + to_string(sqrt(2)))
+print("sqrt(-1) -> " + to_string(sqrt(-1)))  // NaN expected
+
+print("=== math sqrt demo end ===")
+
+/* Expected output (approximate):
+=== math sqrt demo start ===
+sqrt(0) -> 0
+sqrt(9) -> 3
+sqrt(2) -> 1.41421356...
+sqrt(-1) -> nan
+=== math sqrt demo end ===
+*/
diff --git a/examples/math_tan.fun b/examples/math_tan.fun
new file mode 100644
index 0000000..fd63efa
--- /dev/null
+++ b/examples/math_tan.fun
@@ -0,0 +1,28 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+// Demo of tan(x)
+
+print("=== math tan demo start ===")
+
+print("tan(0) -> " + to_string(tan(0)))
+print("tan(0.78539816339) ~ pi/4 -> " + to_string(tan(0.78539816339)))
+
+print("=== math tan demo end ===")
+
+/* Expected output (approximate):
+=== math tan demo start ===
+tan(0) -> 0
+tan(0.78539816339) ~ pi/4 -> 1
+=== math tan demo end ===
+*/
diff --git a/examples/math_trunc.fun b/examples/math_trunc.fun
new file mode 100644
index 0000000..e8f395b
--- /dev/null
+++ b/examples/math_trunc.fun
@@ -0,0 +1,36 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+// Demo of C99-like trunc(x) — rounds toward zero
+
+print("=== math trunc demo start ===")
+
+print("trunc(3.7) -> " + to_string(trunc(3.7)))     // 3
+print("trunc(3.0) -> " + to_string(trunc(3.0)))     // 3
+print("trunc(-3.7) -> " + to_string(trunc(-3.7)))   // -3
+print("trunc(-3.0) -> " + to_string(trunc(-3.0)))   // -3
+print("trunc(0.5) -> " + to_string(trunc(0.5)))     // 0
+print("trunc(-0.5) -> " + to_string(trunc(-0.5)))   // 0
+
+print("=== math trunc demo end ===")
+
+/* Expected output (values):
+=== math trunc demo start ===
+trunc(3.7) -> 3
+trunc(3.0) -> 3
+trunc(-3.7) -> -3
+trunc(-3.0) -> -3
+trunc(0.5) -> 0
+trunc(-0.5) -> 0
+=== math trunc demo end ===
+*/
diff --git a/examples/ripemd160_demo.fun b/examples/ripemd160_demo.fun
index 9f7d06c..0d90f97 100755
--- a/examples/ripemd160_demo.fun
+++ b/examples/ripemd160_demo.fun
@@ -51,8 +51,8 @@ RIPEMD-160(hex: 616263) = 8eb208f7e05d987a9b044a8e98c6b087f15a0bfc
 */
 
 /* Actual output:
-RIPEMD-160("") = d90cc72ef4ad5a2c51f89dc938de0b989c4c4b46
-RIPEMD-160("abc") = 7f339b642aaa074a849c6c1cd860cb049cc792b3
-RIPEMD-160("message digest") = a4f9cd0270a341d05a713df4bf49a3ce8aabde64
-RIPEMD-160(hex: 616263) = 7f339b642aaa074a849c6c1cd860cb049cc792b3
+RIPEMD-160("") = 560e66de427fc2c3399e86c3e1d38c3c6017def2
+RIPEMD-160("abc") = 74266d6b4447493abb790c49e4bfa8f07263bcff
+RIPEMD-160("message digest") = 80ee01c69badb632393a9e05d1e7eebc2f05ac48
+RIPEMD-160(hex: 616263) = 74266d6b4447493abb790c49e4bfa8f07263bcff
 */
diff --git a/examples/ripemd160_example.fun b/examples/ripemd160_example.fun
new file mode 100644
index 0000000..36610cd
--- /dev/null
+++ b/examples/ripemd160_example.fun
@@ -0,0 +1,36 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-02
+ */
+
+// THIS IS BROKEN ACTUALLY! IT DOES NOT CALCULATE THE EXPECTED HASHES!
+
+/*
+ * Example: Using RIPEMD160 from lib/crypt/ripemd160.fun
+ *
+ * Known vectors:
+ *  - "" (empty) => 9c1185a5c5e9fc54612808977ee8f548b2258d31
+ *  - "abc"      => 8eb208f7e05d987a9b04... (full known); we verify via hex of "abc"
+ *  - "The quick brown fox jumps over the lazy dog" => 37f332f68db77bd9d7edd4969571ad671cf9dd3b
+ */
+
+#include <crypt/ripemd160.fun>
+
+r = RIPEMD160()
+
+// empty string
+print(r.ripemd160_str(""))
+
+// "abc"
+print(r.ripemd160_hex("616263"))
+
+// pangram
+print(r.ripemd160_str("The quick brown fox jumps over the lazy dog"))
diff --git a/lib/cli.fun b/lib/cli.fun
new file mode 100644
index 0000000..bf9ea6c
--- /dev/null
+++ b/lib/cli.fun
@@ -0,0 +1,66 @@
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2025-12-30
+ */
+
+// Simple CLI helpers for Fun scripts.
+//
+// argv(): returns an array of the raw arguments passed to the script
+//         (not including the script path). Requires the interpreter to
+//         export FUN_ARGC and FUN_ARGV_i environment variables.
+// parse_args(args): parses flags and positionals from argv() like:
+//   -f  -> flags["f"] = 1
+//   --force -> flags["force"] = 1
+//   --force=42 -> flags["force"] = "42"
+//   -abc -> flags["a"]=1, flags["b"]=1, flags["c"]=1
+
+fun argv()
+  n = to_number(env("FUN_ARGC"))
+  a = []
+  i = 0
+  while (i < n)
+    // Build key without join() to avoid any potential call resolution issues
+    key = "FUN_ARGV_" + to_string(i)
+    push(a, env(key))
+    i = i + 1
+  return a
+
+// Returns: { "flags": map, "positionals": array }
+fun parse_args(args)
+  flags = {}
+  pos = []
+  i = 0
+  n = len(args)
+  while (i < n)
+    s = args[i]
+    slen = len(s)
+    if (slen >= 2 && substr(s, 0, 2) == "--")
+      eq = find(s, "=")
+      if (eq >= 0)
+        key = substr(s, 2, eq - 2)           // between -- and =
+        val = substr(s, eq + 1, slen - (eq + 1))
+        flags[key] = val
+      else
+        key = substr(s, 2, slen - 2)
+        flags[key] = 1
+    else if (slen == 2 && substr(s, 0, 1) == "-")
+      // short -f boolean
+      key = substr(s, 1, 1)
+      flags[key] = 1
+    else if (slen > 2 && substr(s, 0, 1) == "-")
+      // compact short flags like -abc -> a=1, b=1, c=1
+      j = 1
+      while (j < slen)
+        k = substr(s, j, 1)
+        flags[k] = 1
+        j = j + 1
+    else
+      push(pos, s)
+    i = i + 1
+  return { "flags": flags, "positionals": pos }
diff --git a/lib/crypt/ripemd160.fun b/lib/crypt/ripemd160.fun
index f866ab1..bfb4d8b 100644
--- a/lib/crypt/ripemd160.fun
+++ b/lib/crypt/ripemd160.fun
@@ -15,7 +15,10 @@
 
 class RIPEMD160()
   KL = [0, 1518500249, 1859775393, 2400959708, 2840853838]
-  KR = [1352829926, 1548603684, 1836062451, 2054012649, 0]
+  //KR = [1352829926, 1548603684, 1836062451, 2054012649, 0]
+  // Correct KR constants according to RIPEMD-160 specification:
+  // 0x50A28BE6, 0x5C4DD124, 0x6D703EF3, 0x7A6D76E9, 0x00000000
+  KR = [1352829926, 1554976324, 1836072691, 2053994217, 0]
 
   RL = [
     0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
@@ -58,22 +61,23 @@ class RIPEMD160()
     return x
 
   fun rol32(this, x, s)
-    return rol(this.u32(x), s)
+    x = this.u32(x)
+    return this.u32(bor(shl(x, s), shr(x, 32 - s)))
 
   fun add32(this, a, b)
     return this.u32(a + b)
 
   fun F(this, stage, x, y, z)
     if stage == 0
-      return bxor(bxor(x, y), z)
+      return this.u32(bxor(bxor(x, y), z))
     else if stage == 1
-      return bor(band(x, y), band(bnot(x), z))
+      return this.u32(bor(band(x, y), band(bnot(x), z)))
     else if stage == 2
-      return bxor(bor(x, bnot(y)), z)
+      return this.u32(bxor(bor(x, bnot(y)), z))
     else if stage == 3
-      return bor(band(x, z), band(y, bnot(z)))
+      return this.u32(bor(band(x, z), band(y, bnot(z))))
     else
-      return bxor(x, bor(y, bnot(z)))
+      return this.u32(bxor(x, bor(y, bnot(z))))
 
   fun hex_val(this, ch)
     if ch == "0"
@@ -204,7 +208,9 @@ class RIPEMD160()
       B = T
 
       // Right side step
-      Tr = this.add32(this.rol32(this.add32(this.add32(Ar, this.F(stage_r, Br, Cr, Dr)), this.add32(M[this.RR[j]], this.KR[stage_r])), this.SR[j]), Er)
+      // Note: Right branch uses F in reverse stage order (stage_r),
+      // but the constants KR are indexed by the forward round index (stage).
+      Tr = this.add32(this.rol32(this.add32(this.add32(Ar, this.F(stage_r, Br, Cr, Dr)), this.add32(M[this.RR[j]], this.KR[stage])), this.SR[j]), Er)
       Ar = Er
       Er = Dr
       Dr = this.rol32(Cr, 10)
@@ -230,11 +236,19 @@ class RIPEMD160()
     h3 = state[3]
     h4 = state[4]
     
-    state[0] = this.add32(h1, this.add32(B, Cr))
-    state[1] = this.add32(h2, this.add32(C, Dr))
-    state[2] = this.add32(h3, this.add32(D, Er))
-    state[3] = this.add32(h4, this.add32(E, Ar))
-    state[4] = this.add32(h0, this.add32(A, Br))
+    // Final state combination (canonical RIPEMD-160):
+    // T  = h1 + Cl + Dr
+    // h1 = h2 + Dl + Er
+    // h2 = h3 + El + Ar
+    // h3 = h4 + Al + Br
+    // h4 = h0 + Bl + Cr
+    // h0 = T
+    T = this.add32(h1, this.add32(C, Dr))
+    state[1] = this.add32(h2, this.add32(D, Er))
+    state[2] = this.add32(h3, this.add32(E, Ar))
+    state[3] = this.add32(h4, this.add32(A, Br))
+    state[4] = this.add32(h0, this.add32(B, Cr))
+    state[0] = T
     return state
 
   fun ripemd160_bytes(this, bytes)
diff --git a/lib/crypt/ripemd160_new_try.fun b/lib/crypt/ripemd160_new_try.fun
new file mode 100644
index 0000000..41ba167
--- /dev/null
+++ b/lib/crypt/ripemd160_new_try.fun
@@ -0,0 +1,316 @@
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-02
+ */
+
+// THIS IS BROKEN ACTUALLY! IT DOES NOT CALCULATE THE EXPECTED HASHES!
+
+// lib/crypt/ripemd160.fun
+// Pure Fun implementation of RIPEMD-160 operating on hex-string or ASCII inputs.
+//
+// Public API (class):
+//   rip = RIPEMD160()
+//   rip.ripemd160_hex(hexStr) -> digest hex string (lowercase)
+//   rip.ripemd160_str("abc")  -> digest hex string of ASCII bytes
+
+#include <strings.fun>
+
+class RIPEMD160()
+  // 32-bit helpers (match style from md5.fun)
+  fun u32(this, x)
+    m = 4294967296
+    while x < 0
+      x = x + m
+    while x >= m
+      x = x - m
+    return x
+
+  fun add32(this, a, b)
+    return this.u32(a + b)
+
+  fun add32_5(this, a, b, c, d, e)
+    return this.u32(this.u32(this.u32(this.u32(a + b) + c) + d) + e)
+
+  fun rol32(this, x, s)
+    return rol(this.u32(x), s)
+
+  fun and32(this, a, b)
+    return band(this.u32(a), this.u32(b))
+
+  fun or32(this, a, b)
+    return bor(this.u32(a), this.u32(b))
+
+  fun xor32(this, a, b)
+    return bxor(this.u32(a), this.u32(b))
+
+  fun not32(this, x)
+    return bnot(this.u32(x))
+
+  // hex helpers (same as md5/sha files)
+  fun hex_val(this, ch)
+    if (ch == "0")
+      return 0
+    else if (ch == "1")
+      return 1
+    else if (ch == "2")
+      return 2
+    else if (ch == "3")
+      return 3
+    else if (ch == "4")
+      return 4
+    else if (ch == "5")
+      return 5
+    else if (ch == "6")
+      return 6
+    else if (ch == "7")
+      return 7
+    else if (ch == "8")
+      return 8
+    else if (ch == "9")
+      return 9
+    else if (ch == "a" || ch == "A")
+      return 10
+    else if (ch == "b" || ch == "B")
+      return 11
+    else if (ch == "c" || ch == "C")
+      return 12
+    else if (ch == "d" || ch == "D")
+      return 13
+    else if (ch == "e" || ch == "E")
+      return 14
+    else if (ch == "f" || ch == "F")
+      return 15
+    else
+      return 0
+
+  fun byte_from_hex_pair(this, hh)
+    hi = this.hex_val(substr(hh, 0, 1))
+    lo = this.hex_val(substr(hh, 1, 1))
+    return hi * 16 + lo
+
+  fun from_hex(this, hex)
+    arr = []
+    i = 0
+    n = len(hex)
+    while i + 1 < n
+      b = this.byte_from_hex_pair(substr(hex, i, 2))
+      push(arr, b)
+      i = i + 2
+    return arr
+
+  fun two_hex(this, n)
+    n = n % 256
+    d = ["0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"]
+    hi = n / 16
+    lo = n % 16
+    parts = [d[hi], d[lo]]
+    return join(parts, "")
+
+  fun bytes_to_hex(this, arr)
+    i = 0
+    out = []
+    while i < len(arr)
+      push(out, this.two_hex(arr[i]))
+      i = i + 1
+    return join(out, "")
+
+  // Padding (RIPEMD-160): like MD4/MD5 — append 0x80, zeros to 56 mod 64, then 64-bit length in little-endian
+  fun pad_bytes(this, bytes)
+    L = len(bytes)
+    out = []
+    i = 0
+    while i < L
+      push(out, bytes[i])
+      i = i + 1
+    push(out, 128)
+    while (len(out) % 64) != 56
+      push(out, 0)
+    len_bits = L * 8
+    j = 0
+    while j < 8
+      b = (len_bits / pow(2, 8 * j)) % 256
+      push(out, b)
+      j = j + 1
+    return out
+
+  fun word32_le(this, b0, b1, b2, b3)
+    return this.u32(b0 + b1 * 256 + b2 * 65536 + b3 * 16777216)
+
+  // RIPEMD-160 boolean functions
+  fun f1(this, x, y, z)
+    return this.xor32(this.xor32(x, y), z)
+
+  fun f2(this, x, y, z)
+    return this.or32(this.and32(x, y), this.and32(this.not32(x), z))
+
+  fun f3(this, x, y, z)
+    return this.xor32(this.or32(x, this.not32(y)), z)
+
+  fun f4(this, x, y, z)
+    return this.or32(this.and32(x, z), this.and32(y, this.not32(z)))
+
+  fun f5(this, x, y, z)
+    return this.xor32(x, this.or32(y, this.not32(z)))
+
+  // Process a 512-bit block
+  fun process_block(this, H, block)
+    // message words X[16] (little-endian)
+    X = []
+    i = 0
+    while i < 16
+      j = i * 4
+      push(X, this.word32_le(block[j], block[j+1], block[j+2], block[j+3]))
+      i = i + 1
+
+    // R and S (left line)
+    R = [
+      0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,
+      7,4,13,1,10,6,15,3,12,0,9,5,2,14,11,8,
+      3,10,14,4,9,15,8,1,2,7,0,6,13,11,5,12,
+      1,9,11,10,0,8,12,4,13,3,7,15,14,5,6,2,
+      4,0,5,9,7,12,2,10,14,1,3,8,11,6,15,13
+    ]
+    S = [
+      11,14,15,12,5,8,7,9,11,13,14,15,6,7,9,8,
+      7,6,8,13,11,9,7,15,7,12,15,9,11,7,13,12,
+      11,13,6,7,14,9,13,15,14,8,13,6,5,12,7,5,
+      11,12,14,15,14,15,9,8,9,14,5,6,8,6,5,12,
+      9,15,5,11,6,8,13,12,5,12,13,14,11,8,5,6
+    ]
+
+    // R' and S' (right line)
+    Rp = [
+      5,14,7,0,9,2,11,4,13,6,15,8,1,10,3,12,
+      6,11,3,7,0,13,5,10,14,15,8,12,4,9,1,2,
+      15,5,1,3,7,14,6,9,11,8,12,2,10,0,4,13,
+      8,6,4,1,3,11,15,0,5,12,2,13,9,7,10,14,
+      12,15,10,4,1,5,8,7,6,2,13,14,0,3,9,11
+    ]
+    Sp = [
+      8,9,9,11,13,15,15,5,7,7,8,11,14,14,12,6,
+      9,13,15,7,12,8,9,11,7,7,12,7,6,15,13,11,
+      9,7,15,11,8,6,6,14,12,13,5,14,13,13,7,5,
+      15,5,8,11,14,14,6,14,6,9,12,9,12,5,15,8,
+      8,5,12,9,12,5,14,6,8,13,6,5,15,13,11,11
+    ]
+
+    // Constants
+    KL = [0, 1518500249, 1859775393, 2400959708, 2840853838]       // 0x00, 0x5A827999, 0x6ED9EBA1, 0x8F1BBCDC, 0xA953FD4E
+    KR = [1352829926, 1548603684, 1836072691, 2053994217, 0]       // 0x50A28BE6, 0x5C4DD124, 0x6D703EF3, 0x7A6D76E9, 0x00000000
+
+    al = H[0]; bl = H[1]; cl = H[2]; dl = H[3]; el = H[4]
+    ar = H[0]; br = H[1]; cr = H[2]; dr = H[3]; er = H[4]
+
+    j = 0
+    while j < 80
+      sL = S[j]
+      sR = Sp[j]
+
+      // select function and constant per round for left lane
+      if (j < 16)
+        fL = this.f1(bl, cl, dl)
+        kL = KL[0]
+      else if (j < 32)
+        fL = this.f2(bl, cl, dl)
+        kL = KL[1]
+      else if (j < 48)
+        fL = this.f3(bl, cl, dl)
+        kL = KL[2]
+      else if (j < 64)
+        fL = this.f4(bl, cl, dl)
+        kL = KL[3]
+      else
+        fL = this.f5(bl, cl, dl)
+        kL = KL[4]
+
+      // right lane
+      if (j < 16)
+        fR = this.f5(br, cr, dr)
+        kR = KR[0]
+      else if (j < 32)
+        fR = this.f4(br, cr, dr)
+        kR = KR[1]
+      else if (j < 48)
+        fR = this.f3(br, cr, dr)
+        kR = KR[2]
+      else if (j < 64)
+        fR = this.f2(br, cr, dr)
+        kR = KR[3]
+      else
+        fR = this.f1(br, cr, dr)
+        kR = KR[4]
+
+      // left step
+      tl = this.add32_5(al, fL, X[R[j]], kL, 0)
+      tl = this.rol32(tl, sL)
+      tl = this.add32(tl, el)
+      al = el
+      el = dl
+      dl = this.rol32(cl, 10)
+      cl = bl
+      bl = tl
+
+      // right step
+      tr = this.add32_5(ar, fR, X[Rp[j]], kR, 0)
+      tr = this.rol32(tr, sR)
+      tr = this.add32(tr, er)
+      ar = er
+      er = dr
+      dr = this.rol32(cr, 10)
+      cr = br
+      br = tr
+
+      j = j + 1
+
+    // combine using originals
+    h0 = H[0]; h1 = H[1]; h2 = H[2]; h3 = H[3]; h4 = H[4]
+    tt = this.add32(h0, this.add32(bl, cr))
+    H[0] = this.add32(h1, this.add32(cl, dr))
+    H[1] = this.add32(h2, this.add32(dl, er))
+    H[2] = this.add32(h3, this.add32(el, ar))
+    H[3] = this.add32(h4, this.add32(al, br))
+    H[4] = tt
+    return H
+
+  fun ripemd160_bytes(this, bytes)
+    // initialize h0..h4
+    H = [1732584193, 4023233417, 2562383102, 271733878, 3285377520]
+    data = this.pad_bytes(bytes)
+    off = 0
+    N = len(data)
+    while off < N
+      block = []
+      i = 0
+      while i < 64
+        push(block, data[off + i])
+        i = i + 1
+      H = this.process_block(H, block)
+      off = off + 64
+
+    // output as little-endian of h0..h4 (20 bytes)
+    out = []
+    j = 0
+    while j < 5
+      v = H[j]
+      push(out, v % 256)
+      push(out, (v / 256) % 256)
+      push(out, (v / 65536) % 256)
+      push(out, (v / 16777216) % 256)
+      j = j + 1
+    return out
+
+  fun ripemd160_hex(this, hexStr)
+    bytes = this.from_hex(hexStr)
+    digest = this.ripemd160_bytes(bytes)
+    return this.bytes_to_hex(digest)
+
+  fun ripemd160_str(this, str)
+    bytes = string_to_bytes_ascii(str)
+    digest = this.ripemd160_bytes(bytes)
+    return this.bytes_to_hex(digest)
diff --git a/lib/io/console.fun b/lib/io/console.fun
index 52c89ad..e2a0cd0 100644
--- a/lib/io/console.fun
+++ b/lib/io/console.fun
@@ -17,6 +17,15 @@ class Console()
     else
       return input(join([q, ": "], ""))
 
+  // Ask for a secret string (e.g., password) without echoing input
+  // Returns the entered string. A trailing newline is not echoed back.
+  fun ask_hidden(this, question)
+    q = to_string(question)
+    if (len(q) == 0)
+      return input_hidden("")
+    else
+      return input_hidden(join([q, ": "], ""))
+
   // Ask a yes/no question; returns 1 for yes, 0 for no
   // Accepts: y, yes, n, no (case-insensitive). Keeps asking until valid.
   fun ask_yes_no(this, question)
diff --git a/lib/io/ini.fun b/lib/io/ini.fun
index b6145e5..6261dec 100644
--- a/lib/io/ini.fun
+++ b/lib/io/ini.fun
@@ -29,7 +29,7 @@ class INI()
   // Load an INI file from path, closing previous one if open.
   // Returns handle (>0) or 0 on error.
   fun load(this, path)
-    if (this.h > 0)
+    if (this.is_open())
       ini_free(this.h)
       this.h = 0
     p = to_string(path)
@@ -39,11 +39,13 @@ class INI()
 
   // True if a dictionary is open.
   fun is_open(this)
-    return this.h > 0
+    // Be robust across runtimes: coerce to number and test non-zero
+    // Avoid using '>' to prevent integer-only GT errors in VM
+    return to_number(this.h) != 0
 
   // Close and free resources. Safe to call multiple times.
   fun close(this)
-    if (this.h > 0)
+    if (this.is_open())
       ini_free(this.h)
       this.h = 0
     return 1
diff --git a/lib/net/http_server.fun b/lib/net/http_server.fun
index dc78dac..06a8402 100644
--- a/lib/net/http_server.fun
+++ b/lib/net/http_server.fun
@@ -84,7 +84,7 @@ class HTTPServer(number port)
         env_vars = "QUERY_STRING='" + query_string + "' "
       if (len(post_data) > 0)
         env_vars = env_vars + "POST_DATA='" + post_data + "' "
-      
+
       res = proc_run(env_vars + " " + "fun" + " " + file_path)
       content = res["out"]
     else
diff --git a/make b/make
index 914b699..a6a0205 100755
--- a/make
+++ b/make
@@ -100,6 +100,8 @@ elif [ "$target" = "freebsd" ]; then
       -DFUN_LINK_STATIC=OFF \
       -DFUN_DEBUG=OFF \
     && cmake --build build --target fun
+elif [ "$target" = "install" ]; then
+  sudo cmake --build build --target install
 elif [ "$target" = "minimal" ]; then
   rm -rf build \
     && cmake -S . -B build \
@@ -159,6 +161,7 @@ else
   echo " - alpine";
   echo " - debug";
   echo " - freebsd";
+  echo " - install";
   echo " - minimal";
   echo " - musl";
   echo " - repl";
diff --git a/scripts/run_examples.sh b/scripts/run_examples.sh
index 1f7f5cd..1690cd7 100755
--- a/scripts/run_examples.sh
+++ b/scripts/run_examples.sh
@@ -69,16 +69,23 @@ fi
 
 rc=0
 for f in "${files[@]}"; do
+  base_name="$(basename "$f")"
+  # If INI support is disabled, skip INI examples to avoid expected failures
+  if [[ "${FUN_WITH_INI:-}" =~ ^(0|OFF|off|false|False)$ ]]; then
+    if [[ "$base_name" == ini_*.fun ]]; then
+      echo "=== Skipping (INI disabled): examples/$base_name ==="
+      continue
+    fi
+  fi
   echo "=== Running: ${f#$ROOT/} ==="
   if ! "$BIN" "$f"; then
     echo "FAILED: ${f#$ROOT/}"
-    base="$(basename "$f")"
-    dest="$EX_DIR/error/$base"
+    dest="$EX_DIR/error/$base_name"
     # Move the failing example to the error folder
     if mv -f "$f" "$dest"; then
-      echo "Moved to: examples/error/$base"
+      echo "Moved to: examples/error/$base_name"
     else
-      echo "warning: failed to move $base to examples/error/" >&2
+      echo "warning: failed to move $base_name to examples/error/" >&2
     fi
     rc=1
   fi
diff --git a/src/bytecode.c b/src/bytecode.c
index f1af0e2..80a4ce7 100644
--- a/src/bytecode.c
+++ b/src/bytecode.c
@@ -189,6 +189,23 @@ static const char *opcode_name(OpCode op) {
         case OP_TK_LABEL: return "TK_LABEL";
         case OP_TK_BUTTON: return "TK_BUTTON";
         case OP_TK_PACK: return "TK_PACK";
+        case OP_FLOOR: return "FLOOR";
+        case OP_CEIL: return "CEIL";
+        case OP_TRUNC: return "TRUNC";
+        case OP_ROUND: return "ROUND";
+        case OP_SIN: return "SIN";
+        case OP_COS: return "COS";
+        case OP_TAN: return "TAN";
+        case OP_EXP: return "EXP";
+        case OP_LOG: return "LOG";
+        case OP_LOG10: return "LOG10";
+        case OP_SQRT: return "SQRT";
+        case OP_GCD: return "GCD";
+        case OP_LCM: return "LCM";
+        case OP_ISQRT: return "ISQRT";
+        case OP_SIGN: return "SIGN";
+        case OP_FMIN: return "FMIN";
+        case OP_FMAX: return "FMAX";
         default: return "???";
     }
 }
diff --git a/src/bytecode.h b/src/bytecode.h
index 0c0e971..7944573 100644
--- a/src/bytecode.h
+++ b/src/bytecode.h
@@ -236,7 +236,32 @@ typedef enum {
     // exceptions (minimal)
     OP_TRY_PUSH,           // operand = handler ip; push handler onto try-stack
     OP_TRY_POP,            // pop current handler
-    OP_THROW               // pops error value; if handler -> jump to it (push err), else print and terminate
+    OP_THROW,              // pops error value; if handler -> jump to it (push err), else print and terminate
+
+    // C99 math.h rounding family (float-aware)
+    OP_FLOOR,             // pops x (int/float); pushes floor(x) (int if integral else float)
+    OP_CEIL,              // pops x (int/float); pushes ceil(x)  (int if integral else float)
+    OP_TRUNC,             // pops x (int/float); pushes trunc(x) (int if integral else float)
+    OP_ROUND,             // pops x (int/float); pushes round(x) (half away from zero)
+
+    // C99 math.h transcendentals (float-aware)
+    OP_SIN,               // pops x (int/float); pushes sin(x)
+    OP_COS,               // pops x (int/float); pushes cos(x)
+    OP_TAN,               // pops x (int/float); pushes tan(x)
+    OP_EXP,               // pops x (int/float); pushes exp(x)
+    OP_LOG,               // pops x (int/float); pushes natural log ln(x)
+    OP_LOG10,             // pops x (int/float); pushes log10(x)
+    OP_SQRT,              // pops x (int/float); pushes sqrt(x)
+
+    // Integer math helpers
+    OP_GCD,               // pops b, a; pushes gcd(|a|,|b|)
+    OP_LCM,               // pops b, a; pushes lcm(|a|,|b|) (0 if either is 0)
+    OP_ISQRT,             // pops x; pushes floor(sqrt(max(0,x))) for integers
+    OP_SIGN,              // pops x; pushes -1, 0, or 1 depending on the sign
+
+    // Min/Max variants (float-aware, C99 semantics)
+    OP_FMIN,              // pops b, a (int/float); pushes fmin(a,b) (NaN handling per C99)
+    OP_FMAX               // pops b, a (int/float); pushes fmax(a,b) (NaN handling per C99)
 } OpCode;
 
 typedef struct {
diff --git a/src/fun.c b/src/fun.c
index 041e306..08ae886 100644
--- a/src/fun.c
+++ b/src/fun.c
@@ -1,4 +1,13 @@
-/**
+/*
+* This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ */
+
+ /*
  * Main entry point for the Fun language interpreter.
  * Builds a CLI that runs a script file if provided; otherwise starts the REPL
  * when compiled with FUN_WITH_REPL enabled.
@@ -85,6 +94,46 @@ int main(int argc, char **argv) {
 
     if (argi < argc) {
         const char *path = argv[argi];
+
+        /* Collect script arguments (everything after script path) and expose via env vars */
+        int sargi = argi + 1; /* first script arg following the script path */
+        int sargc = (sargi < argc) ? (argc - sargi) : 0;
+
+        /* Export FUN_ARGC */
+        {
+            char buf[32];
+            snprintf(buf, sizeof(buf), "%d", sargc);
+            setenv("FUN_ARGC", buf, 1);
+        }
+
+        /* Export FUN_ARGV_i */
+        for (int i = 0; i < sargc; ++i) {
+            char key[32];
+            snprintf(key, sizeof(key), "FUN_ARGV_%d", i);
+            setenv(key, argv[sargi + i], 1);
+        }
+
+        /* Optional: space-joined convenience string FUN_ARGS */
+        if (sargc > 0) {
+            size_t total = 0;
+            for (int i = 0; i < sargc; ++i) {
+                total += strlen(argv[sargi + i]) + 1; /* +1 for space or NUL */
+            }
+            char *joined = (char*)malloc(total);
+            if (joined) {
+                joined[0] = '\0';
+                for (int i = 0; i < sargc; ++i) {
+                    strcat(joined, argv[sargi + i]);
+                    if (i + 1 < sargc) strcat(joined, " ");
+                }
+                setenv("FUN_ARGS", joined, 1);
+                free(joined);
+            }
+        } else {
+            /* Ensure FUN_ARGS is at least cleared for consistency */
+            setenv("FUN_ARGS", "", 1);
+        }
+
         Bytecode *bc = parse_file_to_bytecode(path);
         if (!bc) {
             fprintf(stderr, "Failed to compile script: %s\n", path);
diff --git a/src/fun_test.c b/src/fun_test.c
index 64928f8..fa28b2c 100644
--- a/src/fun_test.c
+++ b/src/fun_test.c
@@ -11,6 +11,7 @@
 #include "value.h"
 #include "vm.h"
 #include <stdio.h>
+#include <math.h>
 
 #define ASSERT_EQ(val, expected) \
     if ((val).type != VAL_INT || (val).i != (expected)) { \
@@ -33,6 +34,25 @@ int main(void) {
     int c3 = bytecode_add_constant(bc, make_int(3));
     int c10 = bytecode_add_constant(bc, make_int(10));
     int c42 = bytecode_add_constant(bc, make_int(42));
+    int cf3_2 = bytecode_add_constant(bc, make_float(3.2));
+    int cf3_5 = bytecode_add_constant(bc, make_float(3.5));
+    int cf3_8 = bytecode_add_constant(bc, make_float(3.8));
+    int cfn3_2 = bytecode_add_constant(bc, make_float(-3.2));
+    int cfn3_5 = bytecode_add_constant(bc, make_float(-3.5));
+    int cfn3_8 = bytecode_add_constant(bc, make_float(-3.8));
+    int cf0 = bytecode_add_constant(bc, make_float(0.0));
+    int cf1 = bytecode_add_constant(bc, make_float(1.0));
+    int cf5 = bytecode_add_constant(bc, make_float(5.0));
+    int c4 = bytecode_add_constant(bc, make_int(4));
+    int c9 = bytecode_add_constant(bc, make_int(9));
+    int c48 = bytecode_add_constant(bc, make_int(48));
+    int c18 = bytecode_add_constant(bc, make_int(18));
+    int c21 = bytecode_add_constant(bc, make_int(21));
+    int c6 = bytecode_add_constant(bc, make_int(6));
+    int c15 = bytecode_add_constant(bc, make_int(15));
+    int c16 = bytecode_add_constant(bc, make_int(16));
+    int cneg5 = bytecode_add_constant(bc, make_int(-5));
+    int c7 = bytecode_add_constant(bc, make_int(7));
 
     // ---------- Arithmetic ----------
     bytecode_add_instruction(bc, OP_LOAD_CONST, c42);
@@ -120,6 +140,156 @@ int main(void) {
     bytecode_add_instruction(bc, OP_LOAD_CONST, c1);
     bytecode_add_instruction(bc, OP_POP, 0);        // dApache-2.0ard 1 (stack now empty)
 
+    // ---------- Rounding (math.h) demo ----------
+    // floor/ceil/trunc/round on representative values
+    int start_round_demo = bc->instr_count;
+    (void)start_round_demo;
+
+    // +3.2
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf3_2);
+    bytecode_add_instruction(bc, OP_FLOOR, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf3_2);
+    bytecode_add_instruction(bc, OP_CEIL, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf3_2);
+    bytecode_add_instruction(bc, OP_TRUNC, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf3_2);
+    bytecode_add_instruction(bc, OP_ROUND, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+
+    // +3.5
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf3_5);
+    bytecode_add_instruction(bc, OP_ROUND, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+
+    // -3.5
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cfn3_5);
+    bytecode_add_instruction(bc, OP_ROUND, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+
+    // -3.2
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cfn3_2);
+    bytecode_add_instruction(bc, OP_FLOOR, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cfn3_2);
+    bytecode_add_instruction(bc, OP_CEIL, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+
+    // integers should be unchanged
+    bytecode_add_instruction(bc, OP_LOAD_CONST, c10);
+    bytecode_add_instruction(bc, OP_FLOOR, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+
+    // ---------- Transcendentals demo ----------
+    // sin(0)=0
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf0);
+    bytecode_add_instruction(bc, OP_SIN, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    // cos(0)=1
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf0);
+    bytecode_add_instruction(bc, OP_COS, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    // tan(0)=0
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf0);
+    bytecode_add_instruction(bc, OP_TAN, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    // exp(0)=1
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf0);
+    bytecode_add_instruction(bc, OP_EXP, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    // log(1)=0
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf1);
+    bytecode_add_instruction(bc, OP_LOG, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    // log10(1)=0
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf1);
+    bytecode_add_instruction(bc, OP_LOG10, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    // sqrt(9)=3
+    bytecode_add_instruction(bc, OP_LOAD_CONST, c9);
+    bytecode_add_instruction(bc, OP_SQRT, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+
+    // ---------- Integer math (gcd/lcm/isqrt/sign) demo ----------
+    // gcd(48,18)=6
+    bytecode_add_instruction(bc, OP_LOAD_CONST, c48);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, c18);
+    bytecode_add_instruction(bc, OP_GCD, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+
+    // lcm(21,6)=42
+    bytecode_add_instruction(bc, OP_LOAD_CONST, c21);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, c6);
+    bytecode_add_instruction(bc, OP_LCM, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+
+    // isqrt cases: 0, 1, 15->3, 16->4
+    bytecode_add_instruction(bc, OP_LOAD_CONST, c0);
+    bytecode_add_instruction(bc, OP_ISQRT, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, c1);
+    bytecode_add_instruction(bc, OP_ISQRT, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, c15);
+    bytecode_add_instruction(bc, OP_ISQRT, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, c16);
+    bytecode_add_instruction(bc, OP_ISQRT, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+
+    // sign(-5)=-1, sign(0)=0, sign(7)=1
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cneg5);
+    bytecode_add_instruction(bc, OP_SIGN, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, c0);
+    bytecode_add_instruction(bc, OP_SIGN, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, c7);
+    bytecode_add_instruction(bc, OP_SIGN, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+
+    // ---------- fmin/fmax demo ----------
+    // fmin(3.2, 4) -> 3.2
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf3_2);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, c4);
+    bytecode_add_instruction(bc, OP_FMIN, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    // fmax(3.2, 4) -> 4
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf3_2);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, c4);
+    bytecode_add_instruction(bc, OP_FMAX, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    // NaN cases
+    double nanv = NAN;
+    int cNaN = bytecode_add_constant(bc, make_float(nanv));
+    // fmin(NaN, 5.0) -> 5.0
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cNaN);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf5);
+    bytecode_add_instruction(bc, OP_FMIN, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    // fmax(NaN, 5.0) -> 5.0
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cNaN);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf5);
+    bytecode_add_instruction(bc, OP_FMAX, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    // fmin(5.0, NaN) -> 5.0
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf5);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cNaN);
+    bytecode_add_instruction(bc, OP_FMIN, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    // fmax(5.0, NaN) -> 5.0
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cf5);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cNaN);
+    bytecode_add_instruction(bc, OP_FMAX, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+    // fmin(NaN, NaN) -> NaN (prints as nan)
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cNaN);
+    bytecode_add_instruction(bc, OP_LOAD_CONST, cNaN);
+    bytecode_add_instruction(bc, OP_FMIN, 0);
+    bytecode_add_instruction(bc, OP_PRINT, 0);
+
     // ---------- HALT ----------
     bytecode_add_instruction(bc, OP_HALT, 0);
 
diff --git a/src/parser.c b/src/parser.c
index f5b69d9..d014a73 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -709,6 +709,20 @@ static int emit_primary(Bytecode *bc, const char *src, size_t len, size_t *pos)
                 free(name);
                 return 1;
             }
+            if (strcmp(name, "input_hidden") == 0) {
+                (*pos)++; /* '(' */
+                int hasPrompt = 0;
+                skip_spaces(src, len, pos);
+                if (*pos < len && src[*pos] != ')') {
+                    if (!emit_expression(bc, src, len, pos)) { parser_fail(*pos, "input_hidden expects 0 or 1 argument"); free(name); return 0; }
+                    hasPrompt = 1;
+                }
+                if (!consume_char(src, len, pos, ')')) { parser_fail(*pos, "Expected ')' after input_hidden arg(s)"); free(name); return 0; }
+                /* operand bit0 = hasPrompt, bit1 = hidden */
+                bytecode_add_instruction(bc, OP_INPUT_LINE, (hasPrompt ? 1 : 0) | 2);
+                free(name);
+                return 1;
+            }
             if (strcmp(name, "proc_run") == 0) {
                 (*pos)++; /* '(' */
                 if (!emit_expression(bc, src, len, pos)) { parser_fail(*pos, "proc_run expects 1 argument (command string)"); free(name); return 0; }
@@ -1728,6 +1742,22 @@ static int emit_primary(Bytecode *bc, const char *src, size_t len, size_t *pos)
                 free(name);
                 return 1;
             }
+            if (strcmp(name, "fmin") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ',')) { parser_fail(*pos, "fmin expects 2 args"); free(name); return 0; }
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "fmin expects 2 args"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_FMIN, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "fmax") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ',')) { parser_fail(*pos, "fmax expects 2 args"); free(name); return 0; }
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "fmax expects 2 args"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_FMAX, 0);
+                free(name);
+                return 1;
+            }
             if (strcmp(name, "clamp") == 0) {
                 (*pos)++; /* '(' */
                 if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ',')) { parser_fail(*pos, "clamp expects 3 args"); free(name); return 0; }
@@ -1744,6 +1774,113 @@ static int emit_primary(Bytecode *bc, const char *src, size_t len, size_t *pos)
                 free(name);
                 return 1;
             }
+            if (strcmp(name, "floor") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "floor expects 1 arg"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_FLOOR, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "ceil") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "ceil expects 1 arg"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_CEIL, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "trunc") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "trunc expects 1 arg"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_TRUNC, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "round") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "round expects 1 arg"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_ROUND, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "sin") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "sin expects 1 arg"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_SIN, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "cos") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "cos expects 1 arg"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_COS, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "tan") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "tan expects 1 arg"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_TAN, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "exp") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "exp expects 1 arg"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_EXP, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "log") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "log expects 1 arg"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_LOG, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "log10") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "log10 expects 1 arg"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_LOG10, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "sqrt") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "sqrt expects 1 arg"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_SQRT, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "gcd") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ',')) { parser_fail(*pos, "gcd expects 2 args"); free(name); return 0; }
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "gcd expects 2 args"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_GCD, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "lcm") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ',')) { parser_fail(*pos, "lcm expects 2 args"); free(name); return 0; }
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "lcm expects 2 args"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_LCM, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "isqrt") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "isqrt expects 1 arg"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_ISQRT, 0);
+                free(name);
+                return 1;
+            }
+            if (strcmp(name, "sign") == 0) {
+                (*pos)++; /* '(' */
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "sign expects 1 arg"); free(name); return 0; }
+                bytecode_add_instruction(bc, OP_SIGN, 0);
+                free(name);
+                return 1;
+            }
             if (strcmp(name, "pow") == 0) {
                 (*pos)++; /* '(' */
                 if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ',')) { parser_fail(*pos, "pow expects 2 args"); free(name); return 0; }
diff --git a/src/vm.c b/src/vm.c
index f2a4470..22a45c4 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -29,9 +29,15 @@
 #include <netdb.h>
 #include <sys/un.h>
 #include <unistd.h>
+/* For hidden input (password) handling in OP_INPUT_LINE */
+#include <termios.h>
 //#include <arpa/inet.h>
 #endif
 
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
 /* Bring in split-out built-ins without changing the build system yet */
 #include "iter.c"
 #include "map.c"
@@ -42,6 +48,11 @@
 // Optional by extensions commonly used code. #ifdef's are in each single file.
 #include "external/curl.c"
 #include "external/ini.c"
+#ifdef FUN_WITH_INI
+/* Central INI handle registry and helpers */
+#include "vm/ini/handles.c"
+#endif
+/* Note: INI opcode handlers are included below; changes in vm/ini/*.c require vm.c to rebuild. */
 #include "external/json.c"
 #include "external/libsql.c"
 #include "external/pcsc.c"
@@ -661,10 +672,27 @@ void vm_run(VM *vm, Bytecode *entry) {
             #include "vm/math/clamp.c"
             #include "vm/math/max.c"
             #include "vm/math/min.c"
+            #include "vm/math/fmax.c"
+            #include "vm/math/fmin.c"
             #include "vm/math/mod.c"
             #include "vm/math/pow.c"
+            #include "vm/math/floor.c"
+            #include "vm/math/ceil.c"
+            #include "vm/math/trunc.c"
+            #include "vm/math/round.c"
+            #include "vm/math/sin.c"
+            #include "vm/math/cos.c"
+            #include "vm/math/tan.c"
+            #include "vm/math/exp.c"
+            #include "vm/math/log.c"
+            #include "vm/math/log10.c"
+            #include "vm/math/sqrt.c"
             #include "vm/math/random_int.c"
             #include "vm/math/random_seed.c"
+            #include "vm/math/gcd.c"
+            #include "vm/math/lcm.c"
+            #include "vm/math/isqrt.c"
+            #include "vm/math/sign.c"
 
             #include "vm/os/env.c"
             #include "vm/os/env_all.c"
@@ -730,6 +758,8 @@ void vm_run(VM *vm, Bytecode *entry) {
             #include "vm/ini/set.c"
             #include "vm/ini/unset.c"
             #include "vm/ini/save.c"
+            #else
+            #include "vm/ini/stubs.c"
             #endif
 
             /* CURL ops */
diff --git a/src/vm/ini/get_bool.c b/src/vm/ini/get_bool.c
index fa886fb..302e287 100644
--- a/src/vm/ini/get_bool.c
+++ b/src/vm/ini/get_bool.c
@@ -23,8 +23,37 @@ case OP_INI_GET_BOOL: {
     dictionary *d = ini_get(h);
     int outb = def;
     if (d && sec && key) {
-        char full[1024]; ini_make_full_key(full, sizeof(full), sec, key);
-        outb = iniparser_getboolean(d, full, def);
+        char full[1024]; char alt[1024];
+        ini_make_full_key(full, sizeof(full), sec, key);
+        memcpy(alt, full, sizeof(alt));
+        for (size_t i = 0; i < sizeof(alt) && alt[i]; ++i) { if (alt[i] == ':') { alt[i] = '.'; break; } }
+        const char *s = iniparser_getstring(d, full, NULL);
+        if (!s) s = iniparser_getstring(d, alt, NULL);
+        if (s) {
+            /* normalize and parse boolean */
+            char buf[256];
+            size_t n = strlen(s);
+            if (n >= 2 && ((s[0]=='"' && s[n-1]=='"') || (s[0]=='\'' && s[n-1]=='\''))) {
+                size_t copy = (n-2) < sizeof(buf)-1 ? (n-2) : sizeof(buf)-1;
+                memcpy(buf, s+1, copy); buf[copy] = '\0';
+                s = buf;
+            }
+            /* trim spaces */
+            while (*s && (unsigned char)*s <= ' ') s++;
+            /* lower copy for textual booleans */
+            char lb[256]; size_t li=0; for (; s[li] && li < sizeof(lb)-1; ++li) lb[li] = (char)tolower((unsigned char)s[li]); lb[li]='\0';
+            if (strcmp(lb, "true")==0 || strcmp(lb, "yes")==0 || strcmp(lb, "on")==0) {
+                outb = 1;
+            } else if (strcmp(lb, "false")==0 || strcmp(lb, "no")==0 || strcmp(lb, "off")==0) {
+                outb = 0;
+            } else {
+                /* numeric */
+                char *endp=NULL; long v = strtol(lb, &endp, 10);
+                outb = (endp && endp!=lb) ? (v!=0) : def;
+            }
+        } else {
+            outb = def;
+        }
     }
     free_value(vdef); free_value(vkey); free_value(vsec); free_value(vh);
     push_value(vm, make_int(outb ? 1 : 0));
diff --git a/src/vm/ini/get_double.c b/src/vm/ini/get_double.c
index 9cf676f..7896621 100644
--- a/src/vm/ini/get_double.c
+++ b/src/vm/ini/get_double.c
@@ -23,8 +23,27 @@ case OP_INI_GET_DOUBLE: {
     dictionary *d = ini_get(h);
     double outd = def;
     if (d && sec && key) {
-        char full[1024]; ini_make_full_key(full, sizeof(full), sec, key);
-        outd = iniparser_getdouble(d, full, def);
+        char full[1024]; char alt[1024];
+        ini_make_full_key(full, sizeof(full), sec, key);
+        memcpy(alt, full, sizeof(alt));
+        for (size_t i = 0; i < sizeof(alt) && alt[i]; ++i) { if (alt[i] == ':') { alt[i] = '.'; break; } }
+        const char *s = iniparser_getstring(d, full, NULL);
+        if (!s) s = iniparser_getstring(d, alt, NULL);
+        if (s) {
+            char buf[256];
+            size_t n = strlen(s);
+            if (n >= 2 && ((s[0]=='"' && s[n-1]=='"') || (s[0]=='\'' && s[n-1]=='\''))) {
+                size_t copy = (n-2) < sizeof(buf)-1 ? (n-2) : sizeof(buf)-1;
+                memcpy(buf, s+1, copy); buf[copy] = '\0';
+                s = buf;
+            }
+            while (*s && (unsigned char)*s <= ' ') s++;
+            char *endp = NULL;
+            double v = strtod(s, &endp);
+            if (endp && endp != s) outd = v; else outd = def;
+        } else {
+            outd = def;
+        }
     }
     free_value(vdef); free_value(vkey); free_value(vsec); free_value(vh);
     push_value(vm, make_float(outd));
diff --git a/src/vm/ini/get_int.c b/src/vm/ini/get_int.c
index 930bea9..4577ca3 100644
--- a/src/vm/ini/get_int.c
+++ b/src/vm/ini/get_int.c
@@ -23,8 +23,29 @@ case OP_INI_GET_INT: {
     dictionary *d = ini_get(h);
     int outi = def;
     if (d && sec && key) {
-        char full[1024]; ini_make_full_key(full, sizeof(full), sec, key);
-        outi = iniparser_getint(d, full, def);
+        char full[1024]; char alt[1024];
+        ini_make_full_key(full, sizeof(full), sec, key);
+        memcpy(alt, full, sizeof(alt));
+        for (size_t i = 0; i < sizeof(alt) && alt[i]; ++i) { if (alt[i] == ':') { alt[i] = '.'; break; } }
+        const char *s = iniparser_getstring(d, full, NULL);
+        if (!s) s = iniparser_getstring(d, alt, NULL);
+        if (s) {
+            /* strip optional quotes and parse */
+            char buf[256];
+            size_t n = strlen(s);
+            if (n >= 2 && ((s[0]=='"' && s[n-1]=='"') || (s[0]=='\'' && s[n-1]=='\''))) {
+                size_t copy = (n-2) < sizeof(buf)-1 ? (n-2) : sizeof(buf)-1;
+                memcpy(buf, s+1, copy); buf[copy] = '\0';
+                s = buf;
+            }
+            /* skip leading spaces */
+            while (*s && (unsigned char)*s <= ' ') s++;
+            char *endp = NULL;
+            long v = strtol(s, &endp, 10);
+            if (endp && endp != s) outi = (int)v; else outi = def;
+        } else {
+            outi = def;
+        }
     }
     free_value(vdef); free_value(vkey); free_value(vsec); free_value(vh);
     push_value(vm, make_int(outi));
diff --git a/src/vm/ini/get_string.c b/src/vm/ini/get_string.c
index fcfa36f..ef44106 100644
--- a/src/vm/ini/get_string.c
+++ b/src/vm/ini/get_string.c
@@ -23,8 +23,19 @@ case OP_INI_GET_STRING: {
     dictionary *d = ini_get(h);
     const char *res = def;
     if (d && sec && key) {
-        char full[1024]; ini_make_full_key(full, sizeof(full), sec, key);
+        char full[1024]; char alt[1024];
+        ini_make_full_key(full, sizeof(full), sec, key);
+        /* Build alternate with dot separator for robustness */
+        ini_make_full_key(alt, sizeof(alt), sec, key);
+        size_t flen = strlen(full);
+        if (flen < sizeof(alt) && flen > 0) { /* create dot version in alt */
+            memcpy(alt, full, flen + 1);
+            for (size_t i = 0; i < flen; ++i) if (alt[i] == ':') { alt[i] = '.'; break; }
+        }
         const char *s = iniparser_getstring(d, full, def);
+        if (s == def) { /* not found, try alternate dot form */
+            s = iniparser_getstring(d, alt, def);
+        }
         res = s ? s : "";
     }
     free_value(vdef); free_value(vkey); free_value(vsec); free_value(vh);
diff --git a/src/vm/ini/handles.c b/src/vm/ini/handles.c
new file mode 100644
index 0000000..2515410
--- /dev/null
+++ b/src/vm/ini/handles.c
@@ -0,0 +1,63 @@
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ */
+
+#ifdef FUN_WITH_INI
+#if defined(__has_include)
+#  if __has_include(<iniparser/iniparser.h>)
+#    include <iniparser/iniparser.h>
+#    include <iniparser/dictionary.h>
+#  elif __has_include(<iniparser.h>)
+#    include <iniparser.h>
+#    include <dictionary.h>
+#  else
+#    error "iniparser headers not found"
+#  endif
+#else
+#  include <iniparser/iniparser.h>
+#  include <iniparser/dictionary.h>
+#endif
+
+#include <ctype.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "handles.h"
+
+IniSlot g_ini[64];
+
+int ini_alloc_handle(dictionary *d) {
+    if (!d) return 0;
+    for (int i = 1; i < (int)(sizeof(g_ini)/sizeof(g_ini[0])); ++i) {
+        if (!g_ini[i].in_use) { g_ini[i].in_use = 1; g_ini[i].dict = d; return i; }
+    }
+    return 0;
+}
+
+dictionary* ini_get(int h) {
+    if (h > 0 && h < (int)(sizeof(g_ini)/sizeof(g_ini[0])) && g_ini[h].in_use) return g_ini[h].dict;
+    return NULL;
+}
+
+int ini_free_handle(int h) {
+    if (h <= 0 || h >= (int)(sizeof(g_ini)/sizeof(g_ini[0])) || !g_ini[h].in_use) return 0;
+    if (g_ini[h].dict) iniparser_freedict(g_ini[h].dict);
+    g_ini[h].dict = NULL;
+    g_ini[h].in_use = 0;
+    return 1;
+}
+
+void ini_make_full_key(char *buf, size_t cap, const char *sec, const char *key) {
+    if (!buf || cap == 0) return;
+    if (!sec) sec = "";
+    if (!key) key = "";
+    /* iniparser expects section:key; lookup is case-insensitive internally */
+    snprintf(buf, cap, "%s:%s", sec, key);
+}
+
+#endif /* FUN_WITH_INI */
diff --git a/src/vm/ini/handles.h b/src/vm/ini/handles.h
index 3c2022f..831936c 100644
--- a/src/vm/ini/handles.h
+++ b/src/vm/ini/handles.h
@@ -27,35 +27,18 @@
 #  include <iniparser/iniparser.h>
 #  include <iniparser/dictionary.h>
 #endif
-#include <stdio.h> /* snprintf for helper */
+#include <stddef.h>
 
 typedef struct { dictionary *dict; int in_use; } IniSlot;
-static IniSlot g_ini[64];
 
-static int ini_alloc_handle(dictionary *d) {
-    for (int i = 1; i < (int)(sizeof(g_ini)/sizeof(g_ini[0])); ++i) {
-        if (!g_ini[i].in_use) { g_ini[i].in_use = 1; g_ini[i].dict = d; return i; }
-    }
-    return 0;
-}
-static dictionary* ini_get(int h) {
-    if (h > 0 && h < (int)(sizeof(g_ini)/sizeof(g_ini[0])) && g_ini[h].in_use) return g_ini[h].dict;
-    return NULL;
-}
-static int ini_free_handle(int h) {
-    if (h <= 0 || h >= (int)(sizeof(g_ini)/sizeof(g_ini[0])) || !g_ini[h].in_use) return 0;
-    if (g_ini[h].dict) iniparser_freedict(g_ini[h].dict);
-    g_ini[h].dict = NULL;
-    g_ini[h].in_use = 0;
-    return 1;
-}
+/* Single global registry (defined in handles.c) */
+extern IniSlot g_ini[64];
 
-/* Helper to build section:key string safely into provided buffer */
-static inline void ini_make_full_key(char *buf, size_t cap, const char *sec, const char *key) {
-    if (!buf || cap == 0) return;
-    if (!sec) sec = "";
-    if (!key) key = "";
-    /* iniparser expects "section:key" */
-    snprintf(buf, cap, "%s:%s", sec, key);
-}
+/* Registry API (implemented in handles.c) */
+int ini_alloc_handle(dictionary *d);
+dictionary* ini_get(int h);
+int ini_free_handle(int h);
+
+/* Helper to build section:key string safely into provided buffer (implemented in handles.c) */
+void ini_make_full_key(char *buf, size_t cap, const char *sec, const char *key);
 #endif /* FUN_WITH_INI */
diff --git a/src/vm/ini/set.c b/src/vm/ini/set.c
index a0affd9..eee9660 100644
--- a/src/vm/ini/set.c
+++ b/src/vm/ini/set.c
@@ -23,9 +23,16 @@ case OP_INI_SET: {
     if (d && sec && key) {
         char *valstr = value_to_string_alloc(&vval);
         if (valstr) {
-            char full[1024]; snprintf(full, sizeof(full), "%s:%s", sec, key);
+            char full[1024]; char alt[1024];
+            ini_make_full_key(full, sizeof(full), sec, key);
+            memcpy(alt, full, sizeof(alt));
+            for (size_t i = 0; i < sizeof(alt) && alt[i]; ++i) { if (alt[i] == ':') { alt[i] = '.'; break; } }
             /* iniparser 4.x does not expose iniparser_set; use dictionary_set */
-            if (dictionary_set(d, full, valstr) == 0) ok = 1; /* 0 means success */
+            if (dictionary_set(d, full, valstr) == 0) {
+                ok = 1; /* 0 means success */
+            } else if (dictionary_set(d, alt, valstr) == 0) {
+                ok = 1;
+            }
             free(valstr);
         }
     }
diff --git a/src/vm/ini/stubs.c b/src/vm/ini/stubs.c
new file mode 100644
index 0000000..1d13fb7
--- /dev/null
+++ b/src/vm/ini/stubs.c
@@ -0,0 +1,104 @@
+/*
+ * This file provides stub handlers for INI opcodes when FUN_WITH_INI is disabled.
+ * Each opcode reports a clear runtime error and returns a safe default.
+ */
+
+/* OP_INI_LOAD: pops path string; pushes 0 (invalid handle) */
+case OP_INI_LOAD: {
+    Value vpath = pop_value(vm);
+    (void)vpath; /* unused */
+    free_value(vpath);
+    fun_vm_fprintf(stderr, "Runtime error: INI support disabled (rebuild with -DFUN_WITH_INI=ON)\n");
+    push_value(vm, make_int(0));
+    break;
+}
+
+/* OP_INI_FREE: pops handle; pushes 0 */
+case OP_INI_FREE: {
+    Value vh = pop_value(vm);
+    free_value(vh);
+    fun_vm_fprintf(stderr, "Runtime error: INI support disabled (rebuild with -DFUN_WITH_INI=ON)\n");
+    push_value(vm, make_int(0));
+    break;
+}
+
+/* Getters: pop args; push defaults (string:"", int:0, double:0.0, bool:0) */
+case OP_INI_GET_STRING: {
+    Value vdef = pop_value(vm);
+    Value vkey = pop_value(vm);
+    Value vsec = pop_value(vm);
+    Value vh = pop_value(vm);
+    free_value(vh); free_value(vsec); free_value(vkey);
+    /* cannot convert here; return empty string */
+    push_value(vm, make_string(""));
+    free_value(vdef);
+    fun_vm_fprintf(stderr, "Runtime error: INI support disabled (rebuild with -DFUN_WITH_INI=ON)\n");
+    break;
+}
+
+case OP_INI_GET_INT: {
+    Value vdef = pop_value(vm);
+    Value vkey = pop_value(vm);
+    Value vsec = pop_value(vm);
+    Value vh = pop_value(vm);
+    free_value(vh); free_value(vsec); free_value(vkey);
+    (void)vdef; /* unused */
+    push_value(vm, make_int(0));
+    fun_vm_fprintf(stderr, "Runtime error: INI support disabled (rebuild with -DFUN_WITH_INI=ON)\n");
+    break;
+}
+
+case OP_INI_GET_DOUBLE: {
+    Value vdef = pop_value(vm);
+    Value vkey = pop_value(vm);
+    Value vsec = pop_value(vm);
+    Value vh = pop_value(vm);
+    free_value(vh); free_value(vsec); free_value(vkey);
+    (void)vdef; /* unused */
+    push_value(vm, make_float(0.0));
+    fun_vm_fprintf(stderr, "Runtime error: INI support disabled (rebuild with -DFUN_WITH_INI=ON)\n");
+    break;
+}
+
+case OP_INI_GET_BOOL: {
+    Value vdef = pop_value(vm);
+    Value vkey = pop_value(vm);
+    Value vsec = pop_value(vm);
+    Value vh = pop_value(vm);
+    free_value(vh); free_value(vsec); free_value(vkey);
+    (void)vdef; /* unused */
+    push_value(vm, make_int(0));
+    fun_vm_fprintf(stderr, "Runtime error: INI support disabled (rebuild with -DFUN_WITH_INI=ON)\n");
+    break;
+}
+
+/* Mutators: return 0 */
+case OP_INI_SET: {
+    Value vval = pop_value(vm);
+    Value vkey = pop_value(vm);
+    Value vsec = pop_value(vm);
+    Value vh = pop_value(vm);
+    free_value(vh); free_value(vsec); free_value(vkey); free_value(vval);
+    fun_vm_fprintf(stderr, "Runtime error: INI support disabled (rebuild with -DFUN_WITH_INI=ON)\n");
+    push_value(vm, make_int(0));
+    break;
+}
+
+case OP_INI_UNSET: {
+    Value vkey = pop_value(vm);
+    Value vsec = pop_value(vm);
+    Value vh = pop_value(vm);
+    free_value(vh); free_value(vsec); free_value(vkey);
+    fun_vm_fprintf(stderr, "Runtime error: INI support disabled (rebuild with -DFUN_WITH_INI=ON)\n");
+    push_value(vm, make_int(0));
+    break;
+}
+
+case OP_INI_SAVE: {
+    Value vpath = pop_value(vm);
+    Value vh = pop_value(vm);
+    free_value(vh); free_value(vpath);
+    fun_vm_fprintf(stderr, "Runtime error: INI support disabled (rebuild with -DFUN_WITH_INI=ON)\n");
+    push_value(vm, make_int(0));
+    break;
+}
diff --git a/src/vm/ini/unset.c b/src/vm/ini/unset.c
index d264f72..8c339c7 100644
--- a/src/vm/ini/unset.c
+++ b/src/vm/ini/unset.c
@@ -20,9 +20,13 @@ case OP_INI_UNSET: {
     const char *sec = (vsec.type==VAL_STRING)?vsec.s:NULL;
     int ok = 0;
     if (d && sec && key) {
-        char full[1024]; snprintf(full, sizeof(full), "%s:%s", sec, key);
-        /* iniparser 4.2.6 dictionary_unset returns void; assume success if inputs are valid */
+        char full[1024]; char alt[1024];
+        ini_make_full_key(full, sizeof(full), sec, key);
+        memcpy(alt, full, sizeof(alt));
+        for (size_t i = 0; i < sizeof(alt) && alt[i]; ++i) { if (alt[i] == ':') { alt[i] = '.'; break; } }
+        /* iniparser 4.2.6 dictionary_unset returns void; remove both forms */
         dictionary_unset(d, full);
+        dictionary_unset(d, alt);
         ok = 1;
     }
     free_value(vkey); free_value(vsec); free_value(vh);
diff --git a/src/vm/io/input_line.c b/src/vm/io/input_line.c
index 8c624d2..938dda9 100644
--- a/src/vm/io/input_line.c
+++ b/src/vm/io/input_line.c
@@ -1,6 +1,10 @@
 case OP_INPUT_LINE: {
-    /* operand: 0 = no prompt; 1 = has prompt (string or any value convertible to string) */
-    int has_prompt = inst.operand ? 1 : 0;
+    /* operand bit flags:
+     *  bit0 (1): has prompt (string or any value convertible to string) — top of stack holds prompt when set
+     *  bit1 (2): hidden input (do not echo typed characters)
+     */
+    int has_prompt = (inst.operand & 1) ? 1 : 0;
+    int hidden = (inst.operand & 2) ? 1 : 0;
     if (has_prompt) {
         /* pop prompt value and print without newline */
         Value pv = pop_value(vm);
@@ -13,6 +17,35 @@ case OP_INPUT_LINE: {
         free_value(pv);
     }
 
+    /* For hidden input, temporarily disable terminal echo if possible */
+    int echo_disabled = 0;
+#ifdef _WIN32
+    if (hidden) {
+        HANDLE hStdin = GetStdHandle(STD_INPUT_HANDLE);
+        if (hStdin != INVALID_HANDLE_VALUE) {
+            DWORD mode;
+            if (GetConsoleMode(hStdin, &mode)) {
+                DWORD newMode = mode & ~(ENABLE_ECHO_INPUT);
+                if (SetConsoleMode(hStdin, newMode)) {
+                    echo_disabled = 1;
+                }
+            }
+        }
+    }
+#else
+    if (hidden) {
+        /* POSIX termios */
+        struct termios oldt;
+        if (tcgetattr(STDIN_FILENO, &oldt) == 0) {
+            struct termios newt = oldt;
+            newt.c_lflag &= ~(ECHO);
+            if (tcsetattr(STDIN_FILENO, TCSANOW, &newt) == 0) {
+                echo_disabled = 1;
+            }
+        }
+    }
+#endif
+
     /* read a line from stdin, dynamically grow buffer */
     size_t cap = 128;
     size_t len = 0;
@@ -20,7 +53,8 @@ case OP_INPUT_LINE: {
     if (!buf) {
         fprintf(stderr, "Runtime error: out of memory reading input");
         push_value(vm, make_string(""));
-        break;
+        /* On early exit, try to restore echo if we turned it off */
+        goto restore_echo_and_break;
     }
 
     int ch;
@@ -68,5 +102,36 @@ case OP_INPUT_LINE: {
     free(buf);
 
 push_done:
+    /* If we disabled echo, restore terminal settings and print a newline for UX */
+#ifdef _WIN32
+    if (echo_disabled) {
+        HANDLE hStdin = GetStdHandle(STD_INPUT_HANDLE);
+        if (hStdin != INVALID_HANDLE_VALUE) {
+            DWORD mode;
+            if (GetConsoleMode(hStdin, &mode)) {
+                /* Re-enable ECHO flag */
+                mode |= ENABLE_ECHO_INPUT;
+                SetConsoleMode(hStdin, mode);
+            }
+        }
+        if (has_prompt) {
+            fputc('\n', stdout);
+            fflush(stdout);
+        }
+    }
+#else
+    if (echo_disabled) {
+        struct termios t;
+        if (tcgetattr(STDIN_FILENO, &t) == 0) {
+            t.c_lflag |= ECHO;
+            tcsetattr(STDIN_FILENO, TCSANOW, &t);
+        }
+        if (has_prompt) {
+            fputc('\n', stdout);
+            fflush(stdout);
+        }
+    }
+#endif
+restore_echo_and_break:
     break;
 }
diff --git a/src/vm/math/ceil.c b/src/vm/math/ceil.c
new file mode 100644
index 0000000..bda8d29
--- /dev/null
+++ b/src/vm/math/ceil.c
@@ -0,0 +1,43 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+/**
+* @file ceil.c
+ * @brief Implements the OP_CEIL opcode using C99 math.h ceil().
+ */
+
+#include <math.h>
+
+case OP_CEIL: {
+    Value v = pop_value(vm);
+    if (v.type == VAL_INT) {
+        /* ceil(n) == n for integers */
+        push_value(vm, make_int(v.i));
+        free_value(v);
+    } else if (v.type == VAL_FLOAT) {
+        double r = ceil(v.d);
+        if (r >= (double)INT64_MIN && r <= (double)INT64_MAX) {
+            int64_t ii = (int64_t)r;
+            if ((double)ii == r) {
+                push_value(vm, make_int(ii));
+            } else {
+                push_value(vm, make_float(r));
+            }
+        } else {
+            push_value(vm, make_float(r));
+        }
+        free_value(v);
+    } else {
+        fprintf(stderr, "Runtime type error: CEIL expects number, got %s\n", value_type_name(v.type));
+        exit(1);
+    }
+    break;
+}
diff --git a/src/vm/math/cos.c b/src/vm/math/cos.c
new file mode 100644
index 0000000..b5651f0
--- /dev/null
+++ b/src/vm/math/cos.c
@@ -0,0 +1,31 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-03
+ */
+
+/**
+* @file cos.c
+ * @brief Implements the OP_COS opcode using C99 math.h cos().
+ */
+
+#include <math.h>
+
+case OP_COS: {
+    Value v = pop_value(vm);
+    if (v.type == VAL_INT || v.type == VAL_FLOAT) {
+        double x = (v.type == VAL_FLOAT) ? v.d : (double)v.i;
+        double r = cos(x);
+        push_value(vm, make_float(r));
+        free_value(v);
+    } else {
+        fprintf(stderr, "Runtime type error: COS expects number, got %s\n", value_type_name(v.type));
+        exit(1);
+    }
+    break;
+}
diff --git a/src/vm/math/exp.c b/src/vm/math/exp.c
new file mode 100644
index 0000000..8ad99c2
--- /dev/null
+++ b/src/vm/math/exp.c
@@ -0,0 +1,31 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-03
+ */
+
+/**
+* @file exp.c
+ * @brief Implements the OP_EXP opcode using C99 math.h exp().
+ */
+
+#include <math.h>
+
+case OP_EXP: {
+    Value v = pop_value(vm);
+    if (v.type == VAL_INT || v.type == VAL_FLOAT) {
+        double x = (v.type == VAL_FLOAT) ? v.d : (double)v.i;
+        double r = exp(x);
+        push_value(vm, make_float(r));
+        free_value(v);
+    } else {
+        fprintf(stderr, "Runtime type error: EXP expects number, got %s\n", value_type_name(v.type));
+        exit(1);
+    }
+    break;
+}
diff --git a/src/vm/math/floor.c b/src/vm/math/floor.c
new file mode 100644
index 0000000..72e2440
--- /dev/null
+++ b/src/vm/math/floor.c
@@ -0,0 +1,43 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+/**
+* @file floor.c
+ * @brief Implements the OP_FLOOR opcode using C99 math.h floor().
+ */
+
+#include <math.h>
+
+case OP_FLOOR: {
+    Value v = pop_value(vm);
+    if (v.type == VAL_INT) {
+        /* floor(n) == n for integers */
+        push_value(vm, make_int(v.i));
+        free_value(v);
+    } else if (v.type == VAL_FLOAT) {
+        double r = floor(v.d);
+        if (r >= (double)INT64_MIN && r <= (double)INT64_MAX) {
+            int64_t ii = (int64_t)r;
+            if ((double)ii == r) {
+                push_value(vm, make_int(ii));
+            } else {
+                push_value(vm, make_float(r));
+            }
+        } else {
+            push_value(vm, make_float(r));
+        }
+        free_value(v);
+    } else {
+        fprintf(stderr, "Runtime type error: FLOOR expects number, got %s\n", value_type_name(v.type));
+        exit(1);
+    }
+    break;
+}
diff --git a/src/vm/math/fmax.c b/src/vm/math/fmax.c
new file mode 100644
index 0000000..b8504ba
--- /dev/null
+++ b/src/vm/math/fmax.c
@@ -0,0 +1,41 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-03
+ */
+
+/**
+* @file fmax.c
+ * @brief Implements the OP_FMAX opcode using C99 math.h fmax().
+ *        Accepts int or float; follows IEEE-754 NaN handling per fmax.
+ */
+
+#include <math.h>
+
+case OP_FMAX: {
+    Value b = pop_value(vm);
+    Value a = pop_value(vm);
+    if (!((a.type == VAL_INT || a.type == VAL_FLOAT) && (b.type == VAL_INT || b.type == VAL_FLOAT))) {
+        fprintf(stderr, "Runtime type error: FMAX expects numbers, got %s and %s\n",
+                value_type_name(a.type), value_type_name(b.type));
+        exit(1);
+    }
+    double da = (a.type == VAL_FLOAT) ? a.d : (double)a.i;
+    double db = (b.type == VAL_FLOAT) ? b.d : (double)b.i;
+    double r = fmax(da, db);
+    Value out;
+    if (!isnan(r) && !isinf(r) && r >= (double)INT64_MIN && r <= (double)INT64_MAX) {
+        int64_t ii = (int64_t)r;
+        if ((double)ii == r) out = make_int(ii); else out = make_float(r);
+    } else {
+        out = make_float(r);
+    }
+    free_value(a); free_value(b);
+    push_value(vm, out);
+    break;
+}
diff --git a/src/vm/math/fmin.c b/src/vm/math/fmin.c
new file mode 100644
index 0000000..ded0719
--- /dev/null
+++ b/src/vm/math/fmin.c
@@ -0,0 +1,41 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-03
+ */
+
+/**
+* @file fmin.c
+ * @brief Implements the OP_FMIN opcode using C99 math.h fmin().
+ *        Accepts int or float; follows IEEE-754 NaN handling per fmin.
+ */
+
+#include <math.h>
+
+case OP_FMIN: {
+    Value b = pop_value(vm);
+    Value a = pop_value(vm);
+    if (!((a.type == VAL_INT || a.type == VAL_FLOAT) && (b.type == VAL_INT || b.type == VAL_FLOAT))) {
+        fprintf(stderr, "Runtime type error: FMIN expects numbers, got %s and %s\n",
+                value_type_name(a.type), value_type_name(b.type));
+        exit(1);
+    }
+    double da = (a.type == VAL_FLOAT) ? a.d : (double)a.i;
+    double db = (b.type == VAL_FLOAT) ? b.d : (double)b.i;
+    double r = fmin(da, db);
+    Value out;
+    if (!isnan(r) && !isinf(r) && r >= (double)INT64_MIN && r <= (double)INT64_MAX) {
+        int64_t ii = (int64_t)r;
+        if ((double)ii == r) out = make_int(ii); else out = make_float(r);
+    } else {
+        out = make_float(r);
+    }
+    free_value(a); free_value(b);
+    push_value(vm, out);
+    break;
+}
diff --git a/src/vm/math/gcd.c b/src/vm/math/gcd.c
new file mode 100644
index 0000000..106a5e4
--- /dev/null
+++ b/src/vm/math/gcd.c
@@ -0,0 +1,40 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+/**
+* @file gcd.c
+ * @brief Implements the OP_GCD opcode for greatest common divisor.
+ */
+
+case OP_GCD: {
+    Value vb = pop_value(vm);
+    Value va = pop_value(vm);
+    if (!((va.type == VAL_INT) || (va.type == VAL_FLOAT)) ||
+        !((vb.type == VAL_INT) || (vb.type == VAL_FLOAT))) {
+        fprintf(stderr, "Runtime type error: GCD expects numbers, got %s and %s\n",
+                value_type_name(va.type), value_type_name(vb.type));
+        exit(1);
+    }
+    int64_t a = (va.type == VAL_INT) ? va.i : (int64_t)va.d;
+    int64_t b = (vb.type == VAL_INT) ? vb.i : (int64_t)vb.d;
+    if (a == INT64_MIN) a = (int64_t)INT64_MAX; else if (a < 0) a = -a;
+    if (b == INT64_MIN) b = (int64_t)INT64_MAX; else if (b < 0) b = -b;
+    while (b != 0) {
+        int64_t t = a % b;
+        a = b;
+        b = t;
+    }
+    Value res = make_int(a);
+    free_value(va);
+    free_value(vb);
+    push_value(vm, res);
+    break;
+}
diff --git a/src/vm/math/isqrt.c b/src/vm/math/isqrt.c
new file mode 100644
index 0000000..6c60f29
--- /dev/null
+++ b/src/vm/math/isqrt.c
@@ -0,0 +1,47 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+/**
+* @file isqrt.c
+ * @brief Implements the OP_ISQRT opcode for integer square root (floor).
+ */
+
+case OP_ISQRT: {
+    Value v = pop_value(vm);
+    if (!((v.type == VAL_INT) || (v.type == VAL_FLOAT))) {
+        fprintf(stderr, "Runtime type error: ISQRT expects number, got %s\n", value_type_name(v.type));
+        exit(1);
+    }
+    int64_t a = (v.type == VAL_INT) ? v.i : (int64_t)v.d;
+    if (a <= 0) {
+        free_value(v);
+        push_value(vm, make_int(0));
+        break;
+    }
+    /* Binary isqrt inline */
+    uint64_t n = (uint64_t)a;
+    uint64_t x = 0;
+    uint64_t bit = (uint64_t)1 << 62; /* highest even bit set */
+    while (bit > n) bit >>= 2;
+    while (bit != 0) {
+        if (n >= x + bit) {
+            n -= x + bit;
+            x = (x >> 1) + bit;
+        } else {
+            x >>= 1;
+        }
+        bit >>= 2;
+    }
+    int64_t r = (int64_t)x;
+    free_value(v);
+    push_value(vm, make_int(r));
+    break;
+}
diff --git a/src/vm/math/lcm.c b/src/vm/math/lcm.c
new file mode 100644
index 0000000..b477c3e
--- /dev/null
+++ b/src/vm/math/lcm.c
@@ -0,0 +1,48 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+/**
+* @file lcm.c
+ * @brief Implements the OP_LCM opcode for least common multiple.
+ */
+
+case OP_LCM: {
+    Value vb = pop_value(vm);
+    Value va = pop_value(vm);
+    if (!((va.type == VAL_INT) || (va.type == VAL_FLOAT)) ||
+        !((vb.type == VAL_INT) || (vb.type == VAL_FLOAT))) {
+        fprintf(stderr, "Runtime type error: LCM expects numbers, got %s and %s\n",
+                value_type_name(va.type), value_type_name(vb.type));
+        exit(1);
+    }
+    int64_t a = (va.type == VAL_INT) ? va.i : (int64_t)va.d;
+    int64_t b = (vb.type == VAL_INT) ? vb.i : (int64_t)vb.d;
+    if (a == INT64_MIN) a = (int64_t)INT64_MAX; else if (a < 0) a = -a;
+    if (b == INT64_MIN) b = (int64_t)INT64_MAX; else if (b < 0) b = -b;
+    if (a == 0 || b == 0) {
+        free_value(va); free_value(vb);
+        push_value(vm, make_int(0));
+        break;
+    }
+    /* gcd(a,b) */
+    int64_t x = a, y = b;
+    while (y != 0) {
+        int64_t t = x % y; x = y; y = t;
+    }
+    int64_t g = x;
+    /* lcm = (a/g)*b (attempt to reduce overflow) */
+    int64_t l = (a / g) * b;
+    Value res = make_int(l);
+    free_value(va);
+    free_value(vb);
+    push_value(vm, res);
+    break;
+}
diff --git a/src/vm/math/log.c b/src/vm/math/log.c
new file mode 100644
index 0000000..e8bd665
--- /dev/null
+++ b/src/vm/math/log.c
@@ -0,0 +1,36 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-03
+ */
+
+/**
+* @file log.c
+ * @brief Implements the OP_LOG opcode using C99 math.h log() (natural logarithm).
+ */
+
+#include <math.h>
+
+case OP_LOG: {
+    Value v = pop_value(vm);
+    if (v.type == VAL_INT || v.type == VAL_FLOAT) {
+        double x = (v.type == VAL_FLOAT) ? v.d : (double)v.i;
+        if (x <= 0.0) {
+            /* Domain error: return NaN to signal invalid input */
+            push_value(vm, make_float(NAN));
+        } else {
+            double r = log(x);
+            push_value(vm, make_float(r));
+        }
+        free_value(v);
+    } else {
+        fprintf(stderr, "Runtime type error: LOG expects number, got %s\n", value_type_name(v.type));
+        exit(1);
+    }
+    break;
+}
diff --git a/src/vm/math/log10.c b/src/vm/math/log10.c
new file mode 100644
index 0000000..0da07e1
--- /dev/null
+++ b/src/vm/math/log10.c
@@ -0,0 +1,35 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-03
+ */
+
+/**
+* @file log10.c
+ * @brief Implements the OP_LOG10 opcode using C99 math.h log10().
+ */
+
+#include <math.h>
+
+case OP_LOG10: {
+    Value v = pop_value(vm);
+    if (v.type == VAL_INT || v.type == VAL_FLOAT) {
+        double x = (v.type == VAL_FLOAT) ? v.d : (double)v.i;
+        if (x <= 0.0) {
+            push_value(vm, make_float(NAN));
+        } else {
+            double r = log10(x);
+            push_value(vm, make_float(r));
+        }
+        free_value(v);
+    } else {
+        fprintf(stderr, "Runtime type error: LOG10 expects number, got %s\n", value_type_name(v.type));
+        exit(1);
+    }
+    break;
+}
diff --git a/src/vm/math/round.c b/src/vm/math/round.c
new file mode 100644
index 0000000..3f830ff
--- /dev/null
+++ b/src/vm/math/round.c
@@ -0,0 +1,43 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+/**
+* @file round.c
+ * @brief Implements the OP_ROUND opcode using C99 math.h round().
+ *        C99 round() rounds half away from zero.
+ */
+
+#include <math.h>
+
+case OP_ROUND: {
+    Value v = pop_value(vm);
+    if (v.type == VAL_INT) {
+        push_value(vm, make_int(v.i));
+        free_value(v);
+    } else if (v.type == VAL_FLOAT) {
+        double r = round(v.d);
+        if (r >= (double)INT64_MIN && r <= (double)INT64_MAX) {
+            int64_t ii = (int64_t)r;
+            if ((double)ii == r) {
+                push_value(vm, make_int(ii));
+            } else {
+                push_value(vm, make_float(r));
+            }
+        } else {
+            push_value(vm, make_float(r));
+        }
+        free_value(v);
+    } else {
+        fprintf(stderr, "Runtime type error: ROUND expects number, got %s\n", value_type_name(v.type));
+        exit(1);
+    }
+    break;
+}
diff --git a/src/vm/math/sign.c b/src/vm/math/sign.c
new file mode 100644
index 0000000..e54a787
--- /dev/null
+++ b/src/vm/math/sign.c
@@ -0,0 +1,33 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ *  Added: 2026-01-03
+ */
+
+/**
+* @file sign.c
+ * @brief Implements the OP_SIGN opcode returning -1, 0, or 1.
+ */
+
+case OP_SIGN: {
+    Value v = pop_value(vm);
+    int out = 0;
+    if (v.type == VAL_INT) {
+        out = (v.i > 0) - (v.i < 0);
+    } else if (v.type == VAL_FLOAT) {
+        if (v.d > 0.0) out = 1;
+        else if (v.d < 0.0) out = -1;
+        else out = 0;
+    } else {
+        fprintf(stderr, "Runtime type error: SIGN expects number, got %s\n", value_type_name(v.type));
+        exit(1);
+    }
+    free_value(v);
+    push_value(vm, make_int(out));
+    break;
+}
diff --git a/src/vm/math/sin.c b/src/vm/math/sin.c
new file mode 100644
index 0000000..aa989b2
--- /dev/null
+++ b/src/vm/math/sin.c
@@ -0,0 +1,31 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-03
+ */
+
+/**
+* @file sin.c
+ * @brief Implements the OP_SIN opcode using C99 math.h sin().
+ */
+
+#include <math.h>
+
+case OP_SIN: {
+    Value v = pop_value(vm);
+    if (v.type == VAL_INT || v.type == VAL_FLOAT) {
+        double x = (v.type == VAL_FLOAT) ? v.d : (double)v.i;
+        double r = sin(x);
+        push_value(vm, make_float(r));
+        free_value(v);
+    } else {
+        fprintf(stderr, "Runtime type error: SIN expects number, got %s\n", value_type_name(v.type));
+        exit(1);
+    }
+    break;
+}
diff --git a/src/vm/math/sqrt.c b/src/vm/math/sqrt.c
new file mode 100644
index 0000000..aaffee2
--- /dev/null
+++ b/src/vm/math/sqrt.c
@@ -0,0 +1,45 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-03
+ */
+
+/**
+* @file sqrt.c
+ * @brief Implements the OP_SQRT opcode using C99 math.h sqrt().
+ */
+
+#include <math.h>
+
+case OP_SQRT: {
+    Value v = pop_value(vm);
+    if (v.type == VAL_INT || v.type == VAL_FLOAT) {
+        double x = (v.type == VAL_FLOAT) ? v.d : (double)v.i;
+        if (x < 0.0) {
+            push_value(vm, make_float(NAN));
+        } else {
+            double r = sqrt(x);
+            /* preserve int if exactly integral */
+            if (r >= (double)INT64_MIN && r <= (double)INT64_MAX) {
+                int64_t ii = (int64_t)r;
+                if ((double)ii == r) {
+                    push_value(vm, make_int(ii));
+                } else {
+                    push_value(vm, make_float(r));
+                }
+            } else {
+                push_value(vm, make_float(r));
+            }
+        }
+        free_value(v);
+    } else {
+        fprintf(stderr, "Runtime type error: SQRT expects number, got %s\n", value_type_name(v.type));
+        exit(1);
+    }
+    break;
+}
diff --git a/src/vm/math/tan.c b/src/vm/math/tan.c
new file mode 100644
index 0000000..dd7ede3
--- /dev/null
+++ b/src/vm/math/tan.c
@@ -0,0 +1,31 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-03
+ */
+
+/**
+* @file tan.c
+ * @brief Implements the OP_TAN opcode using C99 math.h tan().
+ */
+
+#include <math.h>
+
+case OP_TAN: {
+    Value v = pop_value(vm);
+    if (v.type == VAL_INT || v.type == VAL_FLOAT) {
+        double x = (v.type == VAL_FLOAT) ? v.d : (double)v.i;
+        double r = tan(x);
+        push_value(vm, make_float(r));
+        free_value(v);
+    } else {
+        fprintf(stderr, "Runtime type error: TAN expects number, got %s\n", value_type_name(v.type));
+        exit(1);
+    }
+    break;
+}
diff --git a/src/vm/math/trunc.c b/src/vm/math/trunc.c
new file mode 100644
index 0000000..7442074
--- /dev/null
+++ b/src/vm/math/trunc.c
@@ -0,0 +1,42 @@
+/**
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-03
+ */
+
+/**
+* @file trunc.c
+ * @brief Implements the OP_TRUNC opcode using C99 math.h trunc().
+ */
+
+#include <math.h>
+
+case OP_TRUNC: {
+    Value v = pop_value(vm);
+    if (v.type == VAL_INT) {
+        push_value(vm, make_int(v.i));
+        free_value(v);
+    } else if (v.type == VAL_FLOAT) {
+        double r = trunc(v.d);
+        if (r >= (double)INT64_MIN && r <= (double)INT64_MAX) {
+            int64_t ii = (int64_t)r;
+            if ((double)ii == r) {
+                push_value(vm, make_int(ii));
+            } else {
+                push_value(vm, make_float(r));
+            }
+        } else {
+            push_value(vm, make_float(r));
+        }
+        free_value(v);
+    } else {
+        fprintf(stderr, "Runtime type error: TRUNC expects number, got %s\n", value_type_name(v.type));
+        exit(1);
+    }
+    break;
+}