static JSONCPP_STRING valueToQuotedStringN(const char* value, unsigned length) { if (value == NULL) return ""; // Not sure how to handle unicode... if (strnpbrk(value, "\"\\\b\f\n\r\t", length) == NULL && !containsControlCharacter0(value, length)) return JSONCPP_STRING("\"") + value + "\""; // We have to walk value and escape any special characters. // Appending to JSONCPP_STRING is not efficient, but this should be rare. // (Note: forward slashes are *not* rare, but I am not escaping them.) JSONCPP_STRING::size_type maxsize = length * 2 + 3; // allescaped+quotes+NULL JSONCPP_STRING result; result.reserve(maxsize); // to avoid lots of mallocs result += "\""; char const* end = value + length; for (const char* c = value; c != end; ++c) { switch (*c) { case '\"': result += "\\\""; break; case '\\': result += "\\\\"; break; case '\b': result += "\\b"; break; case '\f': result += "\\f"; break; case '\n': result += "\\n"; break; case '\r': result += "\\r"; break; case '\t': result += "\\t"; break; // case '/': // Even though \/ is considered a legal escape in JSON, a bare // slash is also legal, so I see no reason to escape it. // (I hope I am not misunderstanding something.) // blep notes: actually escaping \/ may be useful in javascript to avoid </ // sequence. // Should add a flag to allow this compatibility mode and prevent this // sequence from occurring. default: if ((isControlCharacter(*c)) || (*c == 0)) { JSONCPP_OSTRINGSTREAM oss; oss << "\\u" << std::hex << std::uppercase << std::setfill('0') << std::setw(4) << static_cast<int>(*c); result += oss.str(); } else { result += *c; } break; } } result += "\""; return result; }