docs: update README.md

README.md

@@ -1,45 +1,98 @@
-md5
-===
+# md5sum
 
-Class to create MD5 checksum from file or string
+> Class to create MD5 checksum from file or string.
 
-<b>Example</b>
+## Example
+
+First clone the source code.
+
+```bash
+git clone https://github.com/dnomd343/md5sum.git
+```
+
+Then create `main.cc` and write the following demo code.
 
 ```c++
+#include <string>
+#include <iostream>
+#include "md5sum.h"
+
+using namespace md5;
+
+int main() {
+    std::string foo = "hello world";
 
-#include "md5/md5.h"
+    /* MD5 from std::string */
+    std::cout << "md5sum: " << md5sum(foo) << std::endl;
 
-int main(int argc,char** argv){
+    /* MD5 from c-string */
+    std::cout << "md5sum: " << md5sum(foo.c_str(), foo.size()) << std::endl;
 
-  char cstring[] = "Foo baz, testing.";
-  std::string str = cstring;
+    /* MD5 from filename */
+    std::cout << "md5file: " << md5file("md5sum/LICENSE") << std::endl;
 
-  /* MD5 from std::string */
-  printf("md5sum: %s\n",  md5(  str ).c_str());
+    /* MD5 from opened file */
+    std::FILE *file = std::fopen("md5sum/LICENSE", "rb");
+    std::cout << "md5file: " << md5file(file) << std::endl;
+    std::fclose(file);
+}
+```
 
-  /* MD5 from c-string */
-  printf("md5sum: %s\n",  md5(  cstring ).c_str());
+Compile them and run.
 
-  /* Short MD5 from c-string */
-  printf("md5sum6: %s\n", md5sum6( cstring ).c_str());
+```bash
+> g++ -std=c++0x -I./md5sum -o demo main.cc md5sum/*.cc
+> ./demo
+md5sum: 5eb63bbbe01eeed093cb22bb8f5acdc3
+md5sum: 5eb63bbbe01eeed093cb22bb8f5acdc3
+md5file: 4ab93db71092d8b54266f83575c1b9e1
+md5file: 4ab93db71092d8b54266f83575c1b9e1
+```
 
-  /* Short MD5 from std::string */
-  printf("md5sum6: %s\n", md5sum6( str ).c_str());
+A more elegant approach is to use cmake to compile, create `CMakeLists.txt` and write the following content.
 
-  /* MD5 from filename */
-  printf("md5file: %s\n", md5file("README.md").c_str());
+```cmake
+cmake_minimum_required(VERSION 3.5)
+project(demo LANGUAGES CXX)
+set(CMAKE_CXX_STANDARD 11)
 
-  /* MD5 from opened file */
-  std::FILE* file = std::fopen("README.md", "rb");
-  printf("md5file: %s\n", md5file(file).c_str());
-  std::fclose(file);
+include_directories(md5sum)
+add_subdirectory(md5sum EXCLUDE_FROM_ALL)
 
-  /* we're done */
-  return EXIT_SUCCESS;
-}
+add_executable(demo main.cc)
+target_link_libraries(demo md5sum)
+```
 
+Using the following command to build and run.
+
+```bash
+> cmake -B ./cmake-build/
+-- The CXX compiler identification is AppleClang 15.0.0.15000040
+-- Detecting CXX compiler ABI info
+-- Detecting CXX compiler ABI info - done
+-- Check for working CXX compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ - skipped
+-- Detecting CXX compile features
+-- Detecting CXX compile features - done
+-- Configuring done (0.4s)
+-- Generating done (0.0s)
+-- Build files have been written to: ...
+> cmake --build ./cmake-build/
+[ 20%] Building CXX object md5sum/CMakeFiles/md5sum.dir/md5.cc.o
+[ 40%] Building CXX object md5sum/CMakeFiles/md5sum.dir/md5_impl.cc.o
+[ 60%] Linking CXX static library libmd5sum.a
+[ 60%] Built target md5sum
+[ 80%] Building CXX object CMakeFiles/demo.dir/main.cc.o
+[100%] Linking CXX executable demo
+[100%] Built target demo
+> ./cmake-build/demo
+md5sum: 5eb63bbbe01eeed093cb22bb8f5acdc3
+md5sum: 5eb63bbbe01eeed093cb22bb8f5acdc3
+md5file: 4ab93db71092d8b54266f83575c1b9e1
+md5file: 4ab93db71092d8b54266f83575c1b9e1
 ```
 
-<b>Compilation in g++</b>
+## License
+
+MIT ©2021 [@ulwanski](https://github.com/ulwanski)
 
-<i>g++ -std=c++0x -o md5 md5.cpp main.cpp</i>
+MIT ©2023 [@dnomd343](https://github.com/dnomd343)