ENH: Implement fileExists in reader

Check if file exists in imstkMeshReader.

Base/Geometry/Reader/imstkMeshReader.cpp

@@ -21,6 +21,8 @@
 
 #include "imstkMeshReader.h"
 
+#include <sys/stat.h>
+
 #include "imstkVTKMeshReader.h"
 #include "imstkVegaMeshReader.h"
 
@@ -30,12 +32,13 @@ namespace imstk {
 std::shared_ptr<Mesh>
 MeshReader::read(const std::string& filePath)
 {
-    FileType meshType = MeshReader::getFileType(filePath);
-    if (meshType == FileType::UNKNOWN)
+    if (!MeshReader::fileExists(filePath))
     {
+        LOG(WARNING) << "MeshReader::read error: file not found: " << filePath;
         return nullptr;
     }
 
+    FileType meshType = MeshReader::getFileType(filePath);
     switch (meshType)
     {
     case FileType::VTK :
@@ -55,6 +58,13 @@ MeshReader::read(const std::string& filePath)
     return nullptr;
 }
 
+bool
+MeshReader::fileExists(const std::string& file)
+{
+    struct stat buf;
+    return (stat(file.c_str(), &buf) == 0);
+}
+
 const MeshReader::FileType
 MeshReader::getFileType(const std::string& filePath)
 {

Base/Geometry/Reader/imstkMeshReader.h

@@ -55,10 +55,15 @@ public:
     ~MeshReader() = default;
 
     ///
-    /// \brief
+    /// \brief read
     ///
     static std::shared_ptr<Mesh> read(const std::string& filePath);
 
+    ///
+    /// \brief fileExists
+    ///
+    static bool fileExists(const std::string& file);
+
 protected:
 
     static const FileType getFileType(const std::string& filePath);