Introduce kiwix::fileReadable

kiwix::fileExists only checks for file existence now
kiwix::fileReadable will check if the file is readable (implicitly checking for file existence also)

include/tools.h

@@ -180,13 +180,22 @@ std::string getFileContent(const std::string& path);
 
 /** checks if file exists.
  *
- * This function returns boolean stating if file exists or not.
+ * This function returns boolean stating if file exists.
  *
  * @param path The absolute path provided in string format.
  * @return Boolean representing if file exists or not.
  */
 bool fileExists(const std::string& path);
 
+/** checks if file is readable.
+ * 
+ * This function returns boolean stating if file is readable.
+ * 
+ * @param path The absolute path provided in string format.
+ * @return Boolean representing if file is readale or not.
+ */
+bool fileReadable(const std::string& path);
+
 /** provides mimetype from filename.
  *
  * This function provides mimetype from file-name.

src/aria2.cpp

@@ -70,7 +70,7 @@ Aria2::Aria2():
   callCmd.push_back(rpc_secret.c_str());
   callCmd.push_back(rpc_port.c_str());
   callCmd.push_back(download_dir.c_str());
-  if (fileExists(session_file)) {
+  if (fileReadable(session_file)) {
     callCmd.push_back(inputFile.c_str());
   }
   callCmd.push_back(session.c_str());

src/book.cpp

@@ -108,7 +108,7 @@ void Book::updateFromXml(const pugi::xml_node& node, const std::string& baseDir)
     path = computeAbsolutePath(baseDir, path);
   }
   m_path = path;
-  m_pathValid = fileExists(path);
+  m_pathValid = fileReadable(path);
   m_title = ATTR("title");
   m_description = ATTR("description");
   m_language = ATTR("language");

src/tools/pathTools.cpp

@@ -305,16 +305,18 @@ std::string kiwix::getFileContent(const std::string& path)
 bool kiwix::fileExists(const std::string& path)
 {
 #ifdef _WIN32
-  return PathFileExistsW(Utf8ToWide(path).c_str());
+  return (_waccess_s(Utf8ToWide(path).c_str(), 0) == 0);
 #else  
-  bool flag = false;
-  std::fstream fin;
-  fin.open(path.c_str(), std::ios::in);
-  if (fin.is_open()) {
-    flag = true;
-  }
-  fin.close();
-  return flag;
+  return (access(path.c_str(), F_OK) == 0); 
+#endif
+}
+
+bool kiwix::fileReadable(const std::string& path)
+{
+#ifdef _WIN32
+  return (_waccess_s(Utf8ToWide(path).c_str(), 4) == 0);
+#else
+  return (access(path.c_str(), R_OK) == 0);
 #endif
 }