posix: add tempfile()

1 files changed, 48 insertions, 0 deletions

diff --git a/nihil.posix/posix.read_file.ccm b/nihil.posix/posix.read_file.ccm
new file mode 100644
index 0000000..c950f67
--- /dev/null
+++ b/nihil.posix/posix.read_file.ccm
@@ -0,0 +1,48 @@
+/*
+ * This source code is released into the public domain.
+ */
+
+module;
+
+#include <expected>
+#include <filesystem>
+#include <iterator>
+#include <ranges>
+#include <span>
+#include <system_error>
+
+#include <fcntl.h>
+#include <unistd.h>
+
+export module nihil.posix:read_file;
+
+import nihil.error;
+import nihil.monad;
+import :fd;
+import :open;
+
+namespace nihil {
+
+/*
+ * Read the contents of a file into an output iterator. 
+ */
+export [[nodiscard]] auto
+read_file(std::filesystem::path const &filename,
+	  std::output_iterator<char> auto &&iter)
+	-> std::expected<void, error>
+{
+	auto file = co_await open(filename, O_RDONLY);
+
+	auto constexpr bufsize = std::size_t{1024};
+	auto buffer = std::array<char, bufsize>{};
+
+	for (;;) {
+		auto read_buf = co_await(read(file, buffer));
+		if (read_buf.empty())
+			co_return {};
+
+		std::ranges::copy(read_buf, iter);
+	}
+}
+
+} // namespace nihil