ceph/src/boost/boost/histogram/detail/term_info.hpp

   1 // Copyright 2021 Hans Dembinski
   2 //
   3 // Distributed under the Boost Software License, Version 1.0.
   4 // (See accompanying file LICENSE_1_0.txt
   5 // or copy at http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #ifndef BOOST_HISTOGRAM_DETAIL_TERM_INFO_HPP
   8 #define BOOST_HISTOGRAM_DETAIL_TERM_INFO_HPP
   9
  10 #include <algorithm>
  11
  12 #if defined __has_include
  13 #if __has_include(<sys/ioctl.h>) && __has_include(<unistd.h>)
  14 #include <sys/ioctl.h>
  15 #include <unistd.h>
  16 #endif
  17 #endif
  18 #include <boost/config.hpp>
  19 #include <cstdlib>
  20 #include <cstring>
  21
  22 namespace boost {
  23 namespace histogram {
  24 namespace detail {
  25
  26 namespace term_info {
  27 class env_t {
  28 public:
  29   env_t(const char* key) {
  30 #if defined(BOOST_MSVC) // msvc complains about using std::getenv
  31     _dupenv_s(&data_, &size_, key);
  32 #else
  33     data_ = std::getenv(key);
  34     if (data_) size_ = std::strlen(data_);
  35 #endif
  36   }
  37
  38   ~env_t() {
  39 #if defined(BOOST_MSVC)
  40     std::free(data_);
  41 #endif
  42   }
  43
  44   bool contains(const char* s) {
  45     const std::size_t n = std::strlen(s);
  46     if (size_ < n) return false;
  47     return std::strstr(data_, s);
  48   }
  49
  50   operator bool() { return size_ > 0; }
  51
  52   explicit operator int() { return size_ ? std::atoi(data_) : 0; }
  53
  54   const char* data() const { return data_; }
  55
  56 private:
  57   char* data_;
  58   std::size_t size_ = 0;
  59 };
  60
  61 inline bool utf8() {
  62   // return false only if LANG exists and does not contain the string UTF
  63   env_t env("LANG");
  64   bool b = true;
  65   if (env) b = env.contains("UTF") || env.contains("utf");
  66   return b;
  67 }
  68
  69 inline int width() {
  70   int w = 0;
  71 #if defined TIOCGWINSZ
  72   struct winsize ws;
  73   ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws);
  74   w = (std::max)(static_cast<int>(ws.ws_col), 0); // not sure if ws_col can be less than 0
  75 #endif
  76   env_t env("COLUMNS");
  77   const int col = (std::max)(static_cast<int>(env), 0);
  78   // if both t and w are set, COLUMNS may be used to restrict width
  79   return w == 0 ? col : (std::min)(col, w);
  80 }
  81 } // namespace term_info
  82
  83 } // namespace detail
  84 } // namespace histogram
  85 } // namespace boost
  86
  87 #endif