implement attach and launch

include/libedbg/error.hpp

@@ -0,0 +1,26 @@
+#ifndef LIBEDBG_INCLUDE_ERROR_H
+#define LIBEDBG_INCLUDE_ERROR_H
+
+#include <stdexcept>
+#include <cstring>
+
+namespace edbg {
+class error final : public std::runtime_error {
+public:
+    [[noreturn]]
+    static void send(const std::string &msg) {
+        throw error(msg);
+    }
+
+    [[noreturn]]
+    static void send_errno(const std::string &pfx) {
+        throw error(pfx + ": " + std::strerror(errno));
+    }
+
+private:
+    explicit error(const std::string &msg) : std::runtime_error(msg) {
+    }
+};
+}
+
+#endif //LIBEDBG_INCLUDE_ERROR_H