Function ShouldUseColor

tests/gtest/gtest-all.cc:4482–4516

Returns true iff Google Test should use colors in the output.

// Returns true iff Google Test should use colors in the output.
bool ShouldUseColor(bool stdout_is_tty) {
  const char* const gtest_color = GTEST_FLAG(color).c_str();

  if (String::CaseInsensitiveCStringEquals(gtest_color, "auto")) {
#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MINGW
    // On Windows the TERM variable is usually not set, but the
    // console there does support colors.
    return stdout_is_tty;
#else
    // On non-Windows platforms, we rely on the TERM variable.
    const char* const term = posix::GetEnv("TERM");
    const bool term_supports_color =
        String::CStringEquals(term, "xterm") ||
        String::CStringEquals(term, "xterm-color") ||
        String::CStringEquals(term, "xterm-256color") ||
        String::CStringEquals(term, "screen") ||
        String::CStringEquals(term, "screen-256color") ||
        String::CStringEquals(term, "tmux") ||
        String::CStringEquals(term, "tmux-256color") ||
        String::CStringEquals(term, "rxvt-unicode") ||
        String::CStringEquals(term, "rxvt-unicode-256color") ||
        String::CStringEquals(term, "linux") ||
        String::CStringEquals(term, "cygwin");
    return stdout_is_tty && term_supports_color;
#endif  // GTEST_OS_WINDOWS
  }

  return String::CaseInsensitiveCStringEquals(gtest_color, "yes") ||
      String::CaseInsensitiveCStringEquals(gtest_color, "true") ||
      String::CaseInsensitiveCStringEquals(gtest_color, "t") ||
      String::CStringEquals(gtest_color, "1");
  // We take "yes", "true", "t", and "1" as meaning "yes".  If the
  // value is neither one of these nor "auto", we treat it as "no" to
  // be conservative.
}

// Helpers for printing colored strings to stdout. Note that on Windows, we
// cannot simply emit special characters and have the terminal change colors.