diff --git a/libs/io/include/psemek/io/stream.hpp b/libs/io/include/psemek/io/stream.hpp
index 9ba9a0ed..11330526 100644
--- a/libs/io/include/psemek/io/stream.hpp
+++ b/libs/io/include/psemek/io/stream.hpp
@@ -11,6 +11,7 @@ namespace psemek::io
 	struct istream
 	{
 		virtual std::size_t read(char * p, std::size_t size) = 0;
+		virtual std::size_t read_all(char * p, std::size_t size);
 
 		virtual ~istream() {}
 	};
@@ -18,6 +19,7 @@ namespace psemek::io
 	struct ostream
 	{
 		virtual std::size_t write(char const * p, std::size_t size) = 0;
+		virtual std::size_t write_all(char const * p, std::size_t size);
 		virtual void flush() {}
 
 		virtual ~ostream() {}
diff --git a/libs/io/source/stream.cpp b/libs/io/source/stream.cpp
index bac3795d..3def2dbb 100644
--- a/libs/io/source/stream.cpp
+++ b/libs/io/source/stream.cpp
@@ -3,6 +3,34 @@
 namespace psemek::io
 {
 
+	std::size_t istream::read_all(char * p, std::size_t size)
+	{
+		auto left = size;
+		while (left > 0)
+		{
+			auto s = read(p, left);
+			if (s == 0)
+				throw istream_end{};
+			p += s;
+			left -= s;
+		}
+		return size;
+	}
+
+	std::size_t ostream::write_all(char const * p, std::size_t size)
+	{
+		auto left = size;
+		while (left > 0)
+		{
+			auto s = write(p, left);
+			if (s == 0)
+				throw ostream_end{};
+			p += s;
+			left -= s;
+		}
+		return size;
+	}
+
 	std::unique_ptr<istream> std_in()
 	{
 		return std::make_unique<file_istream>(stdin);
@@ -18,5 +46,4 @@ namespace psemek::io
 		return std::make_unique<file_ostream>(stderr);
 	}
 
-
 }