diff --git a/src/libutil/windows/processes.cc b/src/libutil/windows/processes.cc index 1d8035c62..cf1949aa2 100644 --- a/src/libutil/windows/processes.cc +++ b/src/libutil/windows/processes.cc @@ -164,6 +164,52 @@ AutoCloseFD nullFD() return nul; } +// Adapted from +// https://blogs.msdn.microsoft.com/twistylittlepassagesallalike/2011/04/23/everyone-quotes-command-line-arguments-the-wrong-way/ +std::string windowsEscape(const std::string & str, bool cmd) +{ + // TODO: This doesn't handle cmd.exe escaping. + if (cmd) { + throw UnimplementedError("cmd.exe escaping is not implemented"); + } + + if (str.find_first_of(" \t\n\v\"") == str.npos && !str.empty()) { + // No need to escape this one, the nonempty contents don't have a special character + return str; + } + std::string buffer; + // Add the opening quote + buffer += '"'; + for (auto iter = str.begin();; ++iter) { + size_t backslashes = 0; + while (iter != str.end() && *iter == '\\') { + ++iter; + ++backslashes; + } + + // We only escape backslashes if: + // - They come immediately before the closing quote + // - They come immediately before a quote in the middle of the string + // Both of these cases break the escaping if not handled. Otherwise backslashes are fine as-is + if (iter == str.end()) { + // Need to escape each backslash + buffer.append(backslashes * 2, '\\'); + // Exit since we've reached the end of the string + break; + } else if (*iter == '"') { + // Need to escape each backslash and the intermediate quote character + buffer.append(backslashes * 2, '\\'); + buffer += "\\\""; + } else { + // Don't escape the backslashes since they won't break the delimiter + buffer.append(backslashes, '\\'); + buffer += *iter; + } + } + // Add the closing quote + return buffer + '"'; +} + Pid spawnProcess(const Path & realProgram, const RunOptions & options, Pipe & out, Pipe & in) { // Setup pipes. @@ -203,7 +249,7 @@ Pid spawnProcess(const Path & realProgram, const RunOptions & options, Pipe & ou for (const auto & arg : options.args) { // TODO: This isn't the right way to escape windows command // See https://learn.microsoft.com/en-us/windows/win32/api/shellapi/nf-shellapi-commandlinetoargvw - cmdline += ' ' + shellEscape(arg); + cmdline += ' ' + windowsEscape(arg, false); } PROCESS_INFORMATION procInfo = {0};