Applying some changes

CMakeLists.txt

@@ -3,11 +3,11 @@
 #
 cmake_minimum_required (VERSION 3.8)
 
-project ("entropy")
+project (entropy VERSION 0.0.2)
 
 set(CMAKE_CXX_STANDARD 20)
-set(CMAKE_CXX_STANDARD_REQUIRED True)
-add_executable (entropy "entropy.cpp"  )
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+add_executable (entropy entropy.cpp)
 
 if (WIN32)
 	set_target_properties(entropy PROPERTIES LINK_FLAGS "/link setargv.obj")

README.md

@@ -15,8 +15,7 @@ this tool, which also supports Linux and macOS.
 
 ## Download
 
-Windows releases are available [here](https://github.com/merces/entropy/releases). In order to run them, 
-you need the latest [Microsoft Visual C++ Redistributable](docs.microsoft.com/en-us/cpp/windows/latest-supported-vc-redist)
+Windows releases are available [here](https://github.com/merces/entropy/releases). In order to run them, you need the latest [Microsoft Visual C++ Redistributable](docs.microsoft.com/en-us/cpp/windows/latest-supported-vc-redist)
 installed.
 
 For Linux and macOS see the [Building](#Building) section.
@@ -25,19 +24,23 @@ For Linux and macOS see the [Building](#Building) section.
 
 Calculating the entropy of a single file:
 
+```bash
     $ ./entropy /bin/ls
     5.85 /bin/ls
+```
 
 Shell expansion is supported too:
 
+```powershell
     PS C:\> .\entropy.exe C:\Users\User\Downloads\*
     7.92 C:\Users\User\Downloads\1.jpeg
     8.00 C:\Users\User\Downloads\setup.exe
     7.58 C:\Users\User\Downloads\nov.pptx
     4.66 C:\Users\User\Downloads\data.bin
     7.99 C:\Users\User\Downloads\pic.png
     4.07 C:\Users\User\Downloads\budget.xls
-
+```
+
 From the above output one could say `/bin/ls` is not packed, `1.jpeg` uses compression,
 `setup.exe` is compressed, `nov.pptx` is compressed (yup, these modern MS Office files are all
 ZIP files indeed), `data.bin` is not compressed, etc. Is that garuanteed? No, it's just math. :nerd_face:
@@ -48,6 +51,7 @@ ZIP files indeed), `data.bin` is not compressed, etc. Is that garuanteed? No, it
 
 Clone the repo:
 
+```bash
     $ git clone https://github.com/merces/entropy.git
     $ cd entropy
 
@@ -57,11 +61,14 @@ If you have CMake installed, build with:
     $ cd build
     $ cmake ..
     $ make
-
+```
+
 Or if you don't, just use `g++`:
 
+```bash
     $ g++ -std=c++20 -o entropy entropy.cpp
-
+```
+
 ### Windows
 
 If you use a recent Visual Studio version, you can clone this repository and open the `CMakeLists.txt` here

entropy.cpp

@@ -6,9 +6,10 @@
 
 double calculate_entropy(const unsigned int counted_bytes[256], const std::streamsize total_length) {
     double entropy = 0.;
+    double temp;
 
     for (int i = 0; i < 256; i++) {
-        double temp = (double)counted_bytes[i] / total_length;
+        temp = static_cast<double>(counted_bytes[i]) / total_length;
 
         if (temp > 0.) {
             entropy += temp * fabs(log2(temp));
@@ -19,9 +20,9 @@ double calculate_entropy(const unsigned int counted_bytes[256], const std::strea
 }
 
 void usage() {
-    std::cout << "entropy calculates the entropy of files, but you need to provide it with a file. :)\n\n" <<
-        "Usage:\n\tentropy FILE\n\n" <<
-        "Examples:\n\tentropy image.png\n\tentropy music.mp3 document.xls\n\tentropy *.exe\n\n" <<
+    std::cout << "entropy calculates the entropy of files, but you need to provide it with a file. :)\n\n"
+        "Usage:\n\tentropy FILE\n\n"
+        "Examples:\n\tentropy image.png\n\tentropy music.mp3 document.xls\n\tentropy *.exe\n\n"
         "For more information and bug reporting, refer to https://github.com/merces/entropy\n";
 }
 
@@ -35,40 +36,43 @@ int main(int argc, char *argv[])
     // Entropy will have two decimal places
     std::cout << std::fixed << std::setprecision(2);
 
+    // 16KB chunks
+    std::vector<char> buff(1024*16, 0);
+    std::streamsize total_bytes_read = 0;
+    std::streamsize bytes_read;
+    unsigned char count;
+
+    // Count occurrence of each possible byte, from zero to 255.
+    unsigned int counted_bytes[256] = {};
+
     for (int i = 1; i < argc; i++) {
         // Skip directories, symlinks, etc
         if (!std::filesystem::is_regular_file(argv[i])) {
+            std::cerr << "\"" << argv[1] << "\"" << " isn't a regular file, skipping." << std::endl;
             continue;
         }
 
         // Open the file
-        std::ifstream f(argv[i], std::ios::binary);
-        if (f.fail()) {
-            std::cerr << "Could not open \"" << argv[i] << "\" for reading.\n";
+        std::ifstream input_file(argv[i], std::ios::binary);
+        if (input_file.fail()) {
+            std::cerr << "Couldn't open \"" << argv[1] << "\" for reading." << std::endl;
             continue;
         }
 
-        // 16KB chunks
-        std::vector<char> buff(1024*16, 0);
-        std::streamsize total_bytes_read = 0;
-
-        // Count occurrence of each possible byte, from zero to 255.
-        unsigned int counted_bytes[256] = { 0 };
-
         // Read file in chunks and count the occurrences of each possible byte (0-255)
-        while (!f.eof()) {
-            f.read(buff.data(), buff.size());
-            auto bytes_read = f.gcount();
+        while (!input_file.eof()) {
+            input_file.read(buff.data(), buff.size());
+            bytes_read = input_file.gcount();
             total_bytes_read += bytes_read;
 
             for (int j = 0; j < bytes_read; j++) {
-                unsigned char c = buff[j];
-                counted_bytes[c]++;
+                count = static_cast<unsigned char> (buff[j]);
+                counted_bytes[count]++;
             }
         }
-
-        f.close();
+        input_file.close();
         std::cout << calculate_entropy(counted_bytes, total_bytes_read) << " " << argv[i] << "\n";
     }
 	return 0;
-}
+}
+