build matches file at end of execution

src/fprint.hpp

@@ -1,9 +1,9 @@
 #pragma once
 
-#include <iterator>
 #include <cstdint>
 #include <cstdio>
 #include <format>
+#include <iterator>
 
 #ifdef _WIN32
 	#define _WIN32_LEAN_AND_MEAN
@@ -32,6 +32,33 @@ namespace swbf {
 		std::FILE* file;
 	};
 
+	template <class Os>
+	struct OsIterator {
+		using iterator_category = std::output_iterator_tag;
+		using value_type = void;
+		using difference_type = std::ptrdiff_t;
+		using pointer = void;
+		using reference = void;
+
+		OsIterator(Os& file) : os(&file) {}
+		OsIterator& operator*() { return *this; }
+		OsIterator& operator++() { return *this; }
+		OsIterator& operator++(int) { return *this; }
+
+		OsIterator& operator=(const char& val) {
+			os->put(val);
+			return *this;
+		}
+
+	   private:
+		Os* os;
+	};
+
+	template <class Stream, class... Args>
+	inline void fprint(Stream& file, std::string_view format, Args&&... args) {
+		std::vformat_to(OsIterator<Stream>(file), format, std::make_format_args(args...));
+	}
+
 	/// Poor Man's C++23
 	template <class... Args>
 	inline void fprint(std::FILE* file, std::string_view format, Args&&... args) {

src/worker.cpp

@@ -7,6 +7,8 @@
 #include <vector>
 #include <thread>
 
+#include <fstream>
+
 #include "ansi.hpp"
 #include "fprint.hpp"
 #include "scramble.hpp"
@@ -23,6 +25,8 @@ namespace swbf {
 		std::uint32_t codeHash;
 		bool done = false;
 
+		std::vector<std::string> matches;
+
 		void DisplayProgress() {
 			if(!done)
 				swbf::fprint(stdout, "{}Thread {:2}: Trying code {}{} {}({:08x}){}", swbf::ansi::Line(threadIndex), threadIndex,
@@ -94,7 +98,8 @@ namespace swbf {
 
 			// There was a match!
 			if(hash == options.targetHash)
-				swbf::fprint(stderr, "match: {} ({:08x})\n", test_buffer, hash);
+				DisplayData().matches.push_back(test_buffer);
+				//swbf::fprint(stderr, "match: {} ({:08x})\n", test_buffer, hash);
 
 			CopyDisplayData();
 
@@ -132,6 +137,23 @@ namespace swbf {
 		}
 
 		pool.join(); // just in case!
+
+		// build the matches file
+		fprint(stdout, "Writing matches file...");
+		std::ofstream ofs("matches.txt");
+
+		if(options.exact)
+			fprint(ofs, "Matches for hash {:8x} for length {}:\n", options.targetHash, options.startLength, options.endLength);
+		else
+			fprint(ofs, "Matches for hash {:8x} for lengths {}..{}:\n", options.targetHash, options.startLength, options.endLength);
+
+		for(auto& td : infoData) {
+			for(auto& match : td.matches) {
+				fprint(ofs, "{}\n", match);
+			}
+
+			td.matches.clear();
+		}
 	}
 
 } // namespace swbf