rang.h

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#ifndef RANG_DOT_HPP
#define RANG_DOT_HPP
 
#if defined(__unix__) || defined(__unix) || defined(__linux__)
#define OS_LINUX
#elif defined(WIN32) || defined(_WIN32) || defined(_WIN64)
#define OS_WIN
#elif defined(__APPLE__) || defined(__MACH__)
#define OS_MAC
#else
#error Unknown Platform
#endif
 
#if defined(OS_LINUX) || defined(OS_MAC)
#include <unistd.h>
 
#elif defined(OS_WIN)
 
#if defined(_WIN32_WINNT) && (_WIN32_WINNT < 0x0600)
#error \
    "Please include rang.hpp before any windows system headers or set _WIN32_WINNT at least to _WIN32_WINNT_VISTA"
#elif !defined(_WIN32_WINNT)
#define _WIN32_WINNT _WIN32_WINNT_VISTA
#endif
 
#include <io.h>
#include <windows.h>
#include <memory>
 
// Only defined in windows 10 onwards, redefining in lower windows since it
// doesn't gets used in lower versions
// https://docs.microsoft.com/en-us/windows/console/getconsolemode
#ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
#define ENABLE_VIRTUAL_TERMINAL_PROCESSING 0x0004
#endif
 
#endif
 
#include <algorithm>
#include <atomic>
#include <cstdlib>
#include <cstring>
#include <iostream>
 
namespace rang {
 
/* For better compability with most of terminals do not use any style settings
 * except of reset, bold and reversed.
 * Note that on Windows terminals bold style is same as fgB color.
 */
enum class style {
  reset     = 0,
  bold      = 1,
  dim       = 2,
  italic    = 3,
  underline = 4,
  blink     = 5,
  rblink    = 6,
  reversed  = 7,
  conceal   = 8,
  crossed   = 9
};
 
enum class fg {
  black   = 30,
  red     = 31,
  green   = 32,
  yellow  = 33,
  blue    = 34,
  magenta = 35,
  cyan    = 36,
  gray    = 37,
  reset   = 39
};
 
enum class bg {
  black   = 40,
  red     = 41,
  green   = 42,
  yellow  = 43,
  blue    = 44,
  magenta = 45,
  cyan    = 46,
  gray    = 47,
  reset   = 49
};
 
enum class fgB {
  black   = 90,
  red     = 91,
  green   = 92,
  yellow  = 93,
  blue    = 94,
  magenta = 95,
  cyan    = 96,
  gray    = 97
};
 
enum class bgB {
  black   = 100,
  red     = 101,
  green   = 102,
  yellow  = 103,
  blue    = 104,
  magenta = 105,
  cyan    = 106,
  gray    = 107
};
 
enum class control {  // Behaviour of rang function calls
  Off   = 0,          // toggle off rang style/color calls
  Auto  = 1,          // (Default) autodect terminal and colorize if needed
  Force = 2           // force ansi color output to non terminal streams
};
// Use rang::setControlMode to set rang control mode
 
enum class winTerm {  // Windows Terminal Mode
  Auto   = 0,         // (Default) automatically detects wheter Ansi or Native API
  Ansi   = 1,         // Force use Ansi API
  Native = 2          // Force use Native API
};
// Use rang::setWinTermMode to explicitly set terminal API for Windows
// Calling rang::setWinTermMode have no effect on other OS
 
namespace rang_implementation {
 
  inline std::atomic<control>& controlMode() noexcept {
    static std::atomic<control> value(control::Auto);
    return value;
  }
 
  inline std::atomic<winTerm>& winTermMode() noexcept {
    static std::atomic<winTerm> termMode(winTerm::Auto);
    return termMode;
  }
 
  inline bool supportsColor() noexcept {
#if defined(OS_LINUX) || defined(OS_MAC)
 
    static const bool result = [] {
      const char* Terms[] = {"ansi",  "color", "console", "cygwin", "gnome",  "konsole", "kterm",
                             "linux", "msys",  "putty",   "rxvt",   "screen", "vt100",   "xterm"};
 
      const char* env_p = std::getenv("TERM");
      if (env_p == nullptr) {
        return false;
      }
      return std::any_of(std::begin(Terms), std::end(Terms),
                         [&](const char* term) { return std::strstr(env_p, term) != nullptr; });
    }();
 
#elif defined(OS_WIN)
    // All windows versions support colors through native console methods
    static constexpr bool result = true;
#endif
    return result;
  }
 
#ifdef OS_WIN
 
  inline bool isMsysPty(int fd) noexcept {
    // Dynamic load for binary compability with old Windows
    const auto ptrGetFileInformationByHandleEx =
        reinterpret_cast<decltype(&GetFileInformationByHandleEx)>(
            GetProcAddress(GetModuleHandle(TEXT("kernel32.dll")), "GetFileInformationByHandleEx"));
    if (!ptrGetFileInformationByHandleEx) {
      return false;
    }
 
    HANDLE h = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
    if (h == INVALID_HANDLE_VALUE) {
      return false;
    }
 
    // Check that it's a pipe:
    if (GetFileType(h) != FILE_TYPE_PIPE) {
      return false;
    }
 
    // POD type is binary compatible with FILE_NAME_INFO from WinBase.h
    // It have the same alignment and used to avoid UB in caller code
    struct MY_FILE_NAME_INFO {
      DWORD FileNameLength;
      WCHAR FileName[MAX_PATH];
    };
 
    auto pNameInfo = std::unique_ptr<MY_FILE_NAME_INFO>(new (std::nothrow) MY_FILE_NAME_INFO());
    if (!pNameInfo) {
      return false;
    }
 
    // Check pipe name is template of
    // {"cygwin-","msys-"}XXXXXXXXXXXXXXX-ptyX-XX
    if (!ptrGetFileInformationByHandleEx(h, FileNameInfo, pNameInfo.get(),
                                         sizeof(MY_FILE_NAME_INFO))) {
      return false;
    }
    std::wstring name(pNameInfo->FileName, pNameInfo->FileNameLength / sizeof(WCHAR));
    if ((name.find(L"msys-") == std::wstring::npos &&
         name.find(L"cygwin-") == std::wstring::npos) ||
        name.find(L"-pty") == std::wstring::npos) {
      return false;
    }
 
    return true;
  }
 
#endif
 
  inline bool isTerminal(const std::streambuf* osbuf) noexcept {
    using std::cerr;
    using std::clog;
    using std::cout;
#if defined(OS_LINUX) || defined(OS_MAC)
    if (osbuf == cout.rdbuf()) {
      static const bool cout_term = isatty(fileno(stdout)) != 0;
      return cout_term;
    } else if (osbuf == cerr.rdbuf() || osbuf == clog.rdbuf()) {
      static const bool cerr_term = isatty(fileno(stderr)) != 0;
      return cerr_term;
    }
#elif defined(OS_WIN)
    if (osbuf == cout.rdbuf()) {
      static const bool cout_term = (_isatty(_fileno(stdout)) || isMsysPty(_fileno(stdout)));
      return cout_term;
    } else if (osbuf == cerr.rdbuf() || osbuf == clog.rdbuf()) {
      static const bool cerr_term = (_isatty(_fileno(stderr)) || isMsysPty(_fileno(stderr)));
      return cerr_term;
    }
#endif
    return false;
  }
 
  template <typename T>
  using enableStd = typename std::enable_if<
      std::is_same<T, rang::style>::value || std::is_same<T, rang::fg>::value ||
          std::is_same<T, rang::bg>::value || std::is_same<T, rang::fgB>::value ||
          std::is_same<T, rang::bgB>::value,
      std::ostream&>::type;
 
#ifdef OS_WIN
 
  struct SGR {          // Select Graphic Rendition parameters for Windows console
    BYTE    fgColor;    // foreground color (0-15) lower 3 rgb bits + intense bit
    BYTE    bgColor;    // background color (0-15) lower 3 rgb bits + intense bit
    BYTE    bold;       // emulated as FOREGROUND_INTENSITY bit
    BYTE    underline;  // emulated as BACKGROUND_INTENSITY bit
    BOOLEAN inverse;    // swap foreground/bold & background/underline
    BOOLEAN conceal;    // set foreground/bold to background/underline
  };
 
  enum class AttrColor : BYTE {  // Color attributes for console screen buffer
    black   = 0,
    red     = 4,
    green   = 2,
    yellow  = 6,
    blue    = 1,
    magenta = 5,
    cyan    = 3,
    gray    = 7
  };
 
  inline HANDLE getConsoleHandle(const std::streambuf* osbuf) noexcept {
    if (osbuf == std::cout.rdbuf()) {
      static const HANDLE hStdout = GetStdHandle(STD_OUTPUT_HANDLE);
      return hStdout;
    } else if (osbuf == std::cerr.rdbuf() || osbuf == std::clog.rdbuf()) {
      static const HANDLE hStderr = GetStdHandle(STD_ERROR_HANDLE);
      return hStderr;
    }
    return INVALID_HANDLE_VALUE;
  }
 
  inline bool setWinTermAnsiColors(const std::streambuf* osbuf) noexcept {
    HANDLE h = getConsoleHandle(osbuf);
    if (h == INVALID_HANDLE_VALUE) {
      return false;
    }
    DWORD dwMode = 0;
    if (!GetConsoleMode(h, &dwMode)) {
      return false;
    }
    dwMode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
    if (!SetConsoleMode(h, dwMode)) {
      return false;
    }
    return true;
  }
 
  inline bool supportsAnsi(const std::streambuf* osbuf) noexcept {
    using std::cerr;
    using std::clog;
    using std::cout;
    if (osbuf == cout.rdbuf()) {
      static const bool cout_ansi = (isMsysPty(_fileno(stdout)) || setWinTermAnsiColors(osbuf));
      return cout_ansi;
    } else if (osbuf == cerr.rdbuf() || osbuf == clog.rdbuf()) {
      static const bool cerr_ansi = (isMsysPty(_fileno(stderr)) || setWinTermAnsiColors(osbuf));
      return cerr_ansi;
    }
    return false;
  }
 
  inline const SGR& defaultState() noexcept {
    static const SGR defaultSgr = []() -> SGR {
      CONSOLE_SCREEN_BUFFER_INFO info;
      WORD                       attrib = FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE;
      if (GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &info) ||
          GetConsoleScreenBufferInfo(GetStdHandle(STD_ERROR_HANDLE), &info)) {
        attrib = info.wAttributes;
      }
      SGR sgr     = {0, 0, 0, 0, FALSE, FALSE};
      sgr.fgColor = attrib & 0x0F;
      sgr.bgColor = (attrib & 0xF0) >> 4;
      return sgr;
    }();
    return defaultSgr;
  }
 
  inline BYTE ansi2attr(BYTE rgb) noexcept {
    static const AttrColor rev[8] = {AttrColor::black,  AttrColor::red,  AttrColor::green,
                                     AttrColor::yellow, AttrColor::blue, AttrColor::magenta,
                                     AttrColor::cyan,   AttrColor::gray};
    return static_cast<BYTE>(rev[rgb]);
  }
 
  inline void setWinSGR(rang::bg col, SGR& state) noexcept {
    if (col != rang::bg::reset) {
      state.bgColor = ansi2attr(static_cast<BYTE>(col) - 40);
    } else {
      state.bgColor = defaultState().bgColor;
    }
  }
 
  inline void setWinSGR(rang::fg col, SGR& state) noexcept {
    if (col != rang::fg::reset) {
      state.fgColor = ansi2attr(static_cast<BYTE>(col) - 30);
    } else {
      state.fgColor = defaultState().fgColor;
    }
  }
 
  inline void setWinSGR(rang::bgB col, SGR& state) noexcept {
    state.bgColor = (BACKGROUND_INTENSITY >> 4) | ansi2attr(static_cast<BYTE>(col) - 100);
  }
 
  inline void setWinSGR(rang::fgB col, SGR& state) noexcept {
    state.fgColor = FOREGROUND_INTENSITY | ansi2attr(static_cast<BYTE>(col) - 90);
  }
 
  inline void setWinSGR(rang::style style, SGR& state) noexcept {
    switch (style) {
      case rang::style::reset:
        state = defaultState();
        break;
      case rang::style::bold:
        state.bold = FOREGROUND_INTENSITY;
        break;
      case rang::style::underline:
      case rang::style::blink:
        state.underline = BACKGROUND_INTENSITY;
        break;
      case rang::style::reversed:
        state.inverse = TRUE;
        break;
      case rang::style::conceal:
        state.conceal = TRUE;
        break;
      default:
        break;
    }
  }
 
  inline SGR& current_state() noexcept {
    static SGR state = defaultState();
    return state;
  }
 
  inline WORD SGR2Attr(const SGR& state) noexcept {
    WORD attrib = 0;
    if (state.conceal) {
      if (state.inverse) {
        attrib = (state.fgColor << 4) | state.fgColor;
        if (state.bold) attrib |= FOREGROUND_INTENSITY | BACKGROUND_INTENSITY;
      } else {
        attrib = (state.bgColor << 4) | state.bgColor;
        if (state.underline) attrib |= FOREGROUND_INTENSITY | BACKGROUND_INTENSITY;
      }
    } else if (state.inverse) {
      attrib = (state.fgColor << 4) | state.bgColor;
      if (state.bold) attrib |= BACKGROUND_INTENSITY;
      if (state.underline) attrib |= FOREGROUND_INTENSITY;
    } else {
      attrib = state.fgColor | (state.bgColor << 4) | state.bold | state.underline;
    }
    return attrib;
  }
 
  template <typename T>
  inline void setWinColorAnsi(std::ostream& os, T const value) {
    os << "\033[" << static_cast<int>(value) << "m";
  }
 
  template <typename T>
  inline void setWinColorNative(std::ostream& os, T const value) {
    const HANDLE h = getConsoleHandle(os.rdbuf());
    if (h != INVALID_HANDLE_VALUE) {
      setWinSGR(value, current_state());
      // Out all buffered text to console with previous settings:
      os.flush();
      SetConsoleTextAttribute(h, SGR2Attr(current_state()));
    }
  }
 
  template <typename T>
  inline enableStd<T> setColor(std::ostream& os, T const value) {
    if (winTermMode() == winTerm::Auto) {
      if (supportsAnsi(os.rdbuf())) {
        setWinColorAnsi(os, value);
      } else {
        setWinColorNative(os, value);
      }
    } else if (winTermMode() == winTerm::Ansi) {
      setWinColorAnsi(os, value);
    } else {
      setWinColorNative(os, value);
    }
    return os;
  }
#else
  template <typename T>
  inline enableStd<T> setColor(std::ostream& os, T const value) {
    return os << "\033[" << static_cast<int>(value) << "m";
  }
#endif
}  // namespace rang_implementation
 
template <typename T>
inline rang_implementation::enableStd<T> operator<<(std::ostream& os, const T value) {
  const control option = rang_implementation::controlMode();
  switch (option) {
    case control::Auto:
      return rang_implementation::supportsColor() && rang_implementation::isTerminal(os.rdbuf())
                 ? rang_implementation::setColor(os, value)
                 : os;
    case control::Force:
      return rang_implementation::setColor(os, value);
    default:
      return os;
  }
}
 
inline void setWinTermMode(const rang::winTerm value) noexcept {
  rang_implementation::winTermMode() = value;
}
 
inline void setControlMode(const control value) noexcept {
  rang_implementation::controlMode() = value;
}
 
}  // namespace rang
 
#undef OS_LINUX
#undef OS_WIN
#undef OS_MAC
 
#endif /* ifndef RANG_DOT_HPP */