diff --git a/BaseLib/FileTools.cpp b/BaseLib/FileTools.cpp
index 4be8108333ec9f5e62dd93a885c7eef667aa4d6e..efb8a65e76ea314e03a1e65898a6dcd50952e275 100644
--- a/BaseLib/FileTools.cpp
+++ b/BaseLib/FileTools.cpp
@@ -71,11 +71,17 @@ size_t findLastPathSeparator(std::string const& path)
 	return path.find_last_of("/\\");
 }
 
+/** Finds the position of last dot.
+ * This could be used to extract file extension.
+ */
 size_t findLastDot(std::string const& path)
 {
 	return path.find_last_of(".");
 }
 
+/** Returns a string with file extension as found by getFileExtension()
+ * dropped.
+ */
 std::string dropFileExtension(std::string const& filename)
 {
 	const size_t p = findLastDot(filename);
diff --git a/BaseLib/FileTools.h b/BaseLib/FileTools.h
index 78d7b1e6c0bd28716a76e392ed9b7040cf0f5c42..50cbc3282d56fc74b3cce165f7eb2def11596584 100644
--- a/BaseLib/FileTools.h
+++ b/BaseLib/FileTools.h
@@ -49,11 +49,17 @@ void truncateFile( std::string const& file_path);
 
 /**
  * Extracts basename from given pathname with extension.
+ *
+ * Returns a string containing everything after the last path separator.
+ * If the the pathname does not contain a path separator original pathname is
+ * returned.
  */
 std::string extractBaseName(std::string const& pathname);
 
 /**
  * Extracts basename from given pathname without its extension.
+ *
+ *  Same as extractBaseName(), but drops the file extension too.
  */
 std::string extractBaseNameWithoutExtension(std::string const& pathname);
 
@@ -70,12 +76,15 @@ std::string getFileExtension(std::string const& filename);
 bool hasFileExtension(std::string const& extension, std::string const& filename);
 
 /**
- * Checks if file_name already contains a qualified path and if not copies the path from source.
+ * Checks if file_name already contains a qualified path and if not copies the
+ * path from source.
  */
 std::string copyPathToFileName(const std::string &file_name, const std::string &source);
 
 /**
  * Extracts the path of a pathname.
+ *
+ * Returns a string up to the last path separator not including it.
  */
 std::string extractPath(std::string const& pathname);
 } // end namespace BaseLib