1 files changed, 194 insertions, 0 deletions
diff --git a/src/cmd_line.hpp b/src/cmd_line.hpp
new file mode 100644
index 0000000..3a65ec7
--- /dev/null
+++ b/src/cmd_line.hpp
@@ -0,0 +1,194 @@
+#pragma once
+
+#include "error.hpp"
+#include "string.hpp"
+
+#include <Windows.h>
+#include <shellapi.h>
+
+#include <cstddef>
+
+#include <memory>
+#include <stdexcept>
+#include <sstream>
+#include <string>
+#include <utility>
+#include <vector>
+
+class CommandLine
+{
+public:
+    static CommandLine query()
+    {
+        return build_from_string(GetCommandLine());
+    }
+
+    static CommandLine build_from_main(int argc, wchar_t* argv[])
+    {
+        if (argc < 1)
+            throw std::range_error(__FUNCTION__ ": invalid argc value");
+
+        std::wstring argv0{argv[0]};
+        --argc;
+        ++argv;
+
+        std::vector<std::wstring> args;
+        args.reserve(argc);
+
+        for (int i = 0; i < argc; ++i)
+            args.emplace_back(argv[i]);
+
+        return {std::move(argv0), std::move(args)};
+    }
+
+    CommandLine() = default;
+
+    bool has_argv0() const
+    {
+        return !argv0.empty();
+    }
+
+    std::wstring get_argv0() const
+    {
+        return argv0;
+    }
+
+    std::wstring escape_argv0() const
+    {
+        return escape(get_argv0());
+    }
+
+    bool has_args() const
+    {
+        return !get_args().empty();
+    }
+
+    const std::vector<std::wstring>& get_args() const
+    {
+        return args;
+    }
+
+    std::vector<std::wstring> escape_args() const
+    {
+        std::vector<std::wstring> safe;
+        safe.reserve(args.size());
+        for (const auto& arg : args)
+            safe.emplace_back(escape(arg));
+        return safe;
+    }
+
+    static constexpr auto sep = L' ';
+
+    std::wstring join_args() const
+    {
+        return string::join(sep, escape_args());
+    }
+
+    std::wstring join() const
+    {
+        if (!has_argv0())
+            throw std::logic_error(__FUNCTION__ ": doesn't have executable path");
+        std::wostringstream oss;
+        oss << escape_argv0();
+        if (has_args())
+            oss << sep << string::join(sep, escape_args());
+        return oss.str();
+    }
+
+private:
+    static CommandLine build_from_string(std::wstring src)
+    {
+        string::trim(src);
+        if (src.empty())
+            return {};
+
+        int argc = 0;
+        std::unique_ptr<wchar_t*, LocalDelete> argv{CommandLineToArgvW(src.c_str(), &argc)};
+
+        if (argv.get() == NULL)
+            error::raise("CommandLineToArgvW");
+
+        if (argc == 0)
+            return {};
+
+        std::wstring argv0{argv.get()[0]};
+
+        std::vector<std::wstring> args;
+        args.reserve(argc - 1);
+
+        for (int i = 1; i < argc; ++i)
+            args.emplace_back(argv.get()[i]);
+
+        return {std::move(argv0), std::move(args)};
+    }
+
+    inline std::wstring escape_for_cmd(const std::wstring& arg)
+    {
+        static constexpr auto escape_symbol = L'^';
+        static constexpr auto dangerous_symbols = L"!\"%&()<>^|";
+
+        auto safe = escape(arg);
+        string::prefix_with(safe, dangerous_symbols, escape_symbol);
+        return safe;
+    }
+
+    static std::wstring escape(const std::wstring& arg)
+    {
+        std::wstring safe;
+        safe.reserve(arg.length() + 2);
+
+        safe.push_back(L'"');
+
+        for (auto it = arg.cbegin(); it != arg.cend(); ++it)
+        {
+            std::size_t numof_backslashes = 0;
+
+            for (; it != arg.cend() && *it == L'\\'; ++it)
+                ++numof_backslashes;
+
+            if (it == arg.cend())
+            {
+                safe.reserve(safe.capacity() + numof_backslashes);
+                safe.append(2 * numof_backslashes, L'\\');
+                break;
+            }
+
+            switch (*it)
+            {
+                case L'"':
+                    safe.reserve(safe.capacity() + numof_backslashes + 1);
+                    safe.append(2 * numof_backslashes + 1, L'\\');
+                    break;
+
+                default:
+                    safe.append(numof_backslashes, L'\\');
+                    break;
+            }
+
+            safe.push_back(*it);
+        }
+
+        safe.push_back(L'"');
+        return safe;
+    }
+
+    struct LocalDelete
+    {
+        void operator()(wchar_t* argv[]) const
+        {
+            LocalFree(argv);
+        }
+    };
+
+    CommandLine(std::vector<std::wstring>&& args)
+        : args{std::move(args)}
+    { }
+
+    CommandLine(std::wstring&& argv0, std::vector<std::wstring>&& args = {})
+        : argv0{std::move(argv0)}
+        , args{std::move(args)}
+    { }
+
+    const std::wstring argv0;
+    const std::vector<std::wstring> args;
+};