Function decode_hex_string

fdbbackup/FileDecoder.actor.cpp:168–213

Decode an ASCII string, e.g., "\x15\x1b\x19\x04\xaf\x0c\x28\x0a", into the binary string.

// Decode an ASCII string, e.g., "\x15\x1b\x19\x04\xaf\x0c\x28\x0a",
// into the binary string.
std::string decode_hex_string(std::string line) {
	size_t i = 0;
	std::string ret;

	while (i <= line.length()) {
		switch (line[i]) {
		case '\\':
			if (i + 2 > line.length()) {
				std::cerr << "Invalid hex string at: " << i << "\n";
				return ret;
			}
			switch (line[i + 1]) {
				char ent, save;
			case '"':
			case '\\':
			case ' ':
			case ';':
				line.erase(i, 1);
				break;
			case 'x':
				if (i + 4 > line.length()) {
					std::cerr << "Invalid hex string at: " << i << "\n";
					return ret;
				}
				char* pEnd;
				save = line[i + 4];
				line[i + 4] = 0;
				ent = char(strtoul(line.data() + i + 2, &pEnd, 16));
				if (*pEnd) {
					std::cerr << "Invalid hex string at: " << i << "\n";
					return ret;
				}
				line[i + 4] = save;
				line.replace(i, 4, 1, ent);
				break;
			default:
				std::cerr << "Invalid hex string at: " << i << "\n";
				return ret;
			}
		default:
			i++;
		}
	}

	return line.substr(0, i);
}

int parseDecodeCommandLine(DecodeParams* param, CSimpleOpt* args) {
	while (args->Next()) {