diff --git a/.gitattributes b/.gitattributes
index 8feea10..d4b5842 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -374,7 +374,7 @@ src/C/H5Fed_retrieve.c -text
 src/C/H5Fed_store.c -text
 src/C/H5Fed_tags.c -text
 src/C/H5Part.c -text
-src/C/H5_attrib.c -text
+src/C/H5_attribs.c -text
 src/C/H5_inquiry.c -text
 src/C/Makefile.am -text
 src/Fortran/H5BlockF.c -text
@@ -458,6 +458,7 @@ src/include/H5Fed_retrieve.h -text
 src/include/H5Fed_store.h -text
 src/include/H5Fed_tags.h -text
 src/include/H5Part.h -text
+src/include/H5_attribs.h -text
 src/include/H5_inquiry.h -text
 src/include/h5core/h5_attribs.h -text
 src/include/h5core/h5_core.h -text
diff --git a/src/C/H5_attrib.c b/src/C/H5_attrib.c
deleted file mode 100644
index 63ba75b..0000000
--- a/src/C/H5_attrib.c
+++ /dev/null
@@ -1,329 +0,0 @@
-/********************** attribute API ****************************************/
-
-/*!
-  \ingroup h5part_c_api
-  \defgroup h5part_c_api_attrib	Reading and Writing Attributes
-*/
-
-/*!
-  \ingroup h5part_c_api_attrib
-
-  Writes a string attribute bound to a file.
-
-  This function creates a new attribute \c name with the string \c value as
-  content. The attribute is bound to the file associated with the file handle 
-  \c f.
-
-  If the attribute already exists an error will be returned. There
-  is currently no way to change the content of an existing attribute.
-
-  \return	\c H5_SUCCESS or error code   
-*/
-h5_int64_t
-H5PartWriteFileAttribString (
-	h5_file_t *f,		/*!< [in] Handle to open file */
-	const char *attrib_name,/*!< [in] Name of attribute to create */
-	const char *attrib_value/*!< [in] Value of attribute */ 
-	) {
-
-	SET_FNAME ( f, __func__ );
-
-   	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
-		return h5_get_errno( f );
-
-	return h5_write_attrib (
-		f,
-		f->root_gid,
-		attrib_name,
-		H5T_NATIVE_CHAR,
-		attrib_value,
-		strlen ( attrib_value ) + 1 );
-}
-
-/*!
-  \ingroup h5part_c_api_attrib
-
-  Writes a string attribute bound to the current time-step.
-
-  This function creates a new attribute \c name with the string \c value as
-  content. The attribute is bound to the current time step in the file given
-  by the file handle \c f.
-
-  If the attribute already exists an error will be returned. There
-  is currently no way to change the content of an existing attribute.
-
-  \return	\c H5_SUCCESS or error code   
-*/
-
-h5_int64_t
-H5PartWriteStepAttribString (
-	h5_file_t *f,		/*!< [in] Handle to open file */
-	const char *attrib_name,/*!< [in] Name of attribute to create */
-	const char *attrib_value/*!< [in] Value of attribute */ 
-	) {
-
-	SET_FNAME ( f, __func__ );
-
-   	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
-		return h5_get_errno( f );
-
-	return h5_write_attrib (
-		f, 
-		f->step_gid,
-		attrib_name,
-		H5T_NATIVE_CHAR,
-		attrib_value,
-		strlen ( attrib_value ) + 1 );
-}
-
-/*!
-  \ingroup h5part_c_api_attrib
-
-  Writes a attribute bound to the current time-step.
-
-  This function creates a new attribute \c name with the string \c value as
-  content. The attribute is bound to the current time step in the file given
-  by the file handle \c f.
-
-  The value of the attribute is given the parameter \c type, which must be one
-  of \c H5T_NATIVE_DOUBLE, \c H5T_NATIVE_INT64 of \c H5T_NATIVE_CHAR, the array
-  \c value and the number of elements \c nelem in the array.
-
-  If the attribute already exists an error will be returned. There
-  is currently no way to change the content of an existing attribute.
-
-  \return	\c H5_SUCCESS or error code   
-*/
-
-h5_int64_t
-H5PartWriteStepAttrib (
-	h5_file_t *f,			/*!< [in] Handle to open file */
-	const char *attrib_name,	/*!< [in] Name of attribute */
-	const h5_int64_t attrib_type,/*!< [in] Type of value. */
-	const void *attrib_value,	/*!< [in] Value of attribute */ 
-	const h5_int64_t attrib_nelem/*!< [in] Number of elements */
-	){
-
-	SET_FNAME ( f, __func__ );
-
-   	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
-		return h5_get_errno( f );
-
-	return h5_write_attrib (
-		f,
-		f->step_gid,
-		attrib_name,
-		(hid_t)attrib_type,
-		attrib_value,
-		attrib_nelem );
-}
-
-/*!
-  \ingroup h5part_c_api_attrib
-
-  Writes a attribute bound to a file.
-
-  This function creates a new attribute \c name with the string \c value as
-  content. The attribute is bound to the file file given by the file handle
-  \c f.
-
-  The value of the attribute is given the parameter \c type, which must be one
-  of H5T_NATIVE_DOUBLE, H5T_NATIVE_INT64 of H5T_NATIVE_CHAR, the array \c value
-  and the number of elements \c nelem in the array.
-
-  If the attribute already exists an error will be returned. There
-  is currently no way to change the content of an existing attribute.
-
-  \return	\c H5_SUCCESS or error code   
-*/
-
-h5_int64_t
-H5PartWriteFileAttrib (
-	h5_file_t *f,			/*!< [in] Handle to open file */
-	const char *attrib_name,	/*!< [in] Name of attribute */
-	const h5_int64_t attrib_type,/*!< [in] Type of value. */
-	const void *attrib_value,	/*!< [in] Value of attribute */ 
-	const h5_int64_t attrib_nelem/*!< [in] Number of elements */
-	) {
-
-	SET_FNAME ( f, __func__ );
-
-   	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
-		return h5_get_errno( f );
-
-	return h5_write_attrib (
-		f,
-		f->root_gid,
-		attrib_name,
-		(hid_t)attrib_type,
-		attrib_value,
-		attrib_nelem );
-}
-
-/*!
-  \ingroup h5part_c_api_attrib
-
-  Gets the number of attributes bound to the current step.
-
-  \return	Number of attributes bound to current time step or error code.
-*/
-h5_int64_t
-H5PartGetNumStepAttribs (
-	h5_file_t *f			/*!< [in] Handle to open file */
-	) {
-
-	SET_FNAME ( f, __func__ );
-
-   	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
-		return h5_get_errno( f );
-
-	return h5_get_num_attribs ( f, f->step_gid );
-}
-
-/*!
-  \ingroup h5part_c_api_attrib
-
-  Gets the number of attributes bound to the file.
-
-  \return	Number of attributes bound to file \c f or error code.
-*/
-h5_int64_t
-H5PartGetNumFileAttribs (
-	h5_file_t *f			/*!< [in] Handle to open file */
-	) {
-
-	SET_FNAME ( f, __func__ );
-
-   	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
-		return h5_get_errno( f );
-
-	return h5_get_num_attribs ( f, f->root_gid );
-}
-
-/*!
-  \ingroup h5part_c_api_attrib
-
-  Gets the name, type and number of elements of the step attribute
-  specified by its index.
-
-  This function can be used to retrieve all attributes bound to the
-  current time-step by looping from \c 0 to the number of attribute
-  minus one.  The number of attributes bound to the current
-  time-step can be queried by calling the function
-  \c H5PartGetNumStepAttribs().
-
-  \return	\c H5_SUCCESS or error code 
-*/
-h5_int64_t
-H5PartGetStepAttribInfo (
-	h5_file_t *f,			/*!< [in]  Handle to open file */
-	const h5_int64_t attrib_idx,/*!< [in]  Index of attribute to
-					           get infos about */
-	char *attrib_name,		/*!< [out] Name of attribute */
-	const h5_int64_t len_of_attrib_name,
-					/*!< [in]  length of buffer \c name */
-	h5_int64_t *attrib_type,	/*!< [out] Type of value. */
-	h5_int64_t *attrib_nelem	/*!< [out] Number of elements */
-	) {
-	
-	SET_FNAME ( f, __func__ );
-
-   	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
-		return h5_get_errno( f );
-
-	return h5_get_attrib_info (
-		f,
-		f->step_gid,
-		attrib_idx,
-		attrib_name,
-		len_of_attrib_name,
-		attrib_type,
-		attrib_nelem );
-}
-
-/*!
-  \ingroup h5part_c_api_attrib
-
-  Gets the name, type and number of elements of the file attribute
-  specified by its index.
-
-  This function can be used to retrieve all attributes bound to the
-  file \c f by looping from \c 0 to the number of attribute minus
-  one.  The number of attributes bound to file \c f can be queried
-  by calling the function \c H5PartGetNumFileAttribs().
-
-  \return	\c H5_SUCCESS or error code 
-*/
-
-h5_int64_t
-H5PartGetFileAttribInfo (
-	h5_file_t *f,			/*!< [in]  Handle to open file */
-	const h5_int64_t attrib_idx,/*!< [in]  Index of attribute to get
-					           infos about */
-	char *attrib_name,		/*!< [out] Name of attribute */
-	const h5_int64_t len_of_attrib_name,
-					/*!< [in]  length of buffer \c name */
-	h5_int64_t *attrib_type,	/*!< [out] Type of value. */
-	h5_int64_t *attrib_nelem	/*!< [out] Number of elements */
-	) {
-
-	SET_FNAME ( f, __func__ );
-
-	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
-		return h5_get_errno ( f );
-
-	return h5_get_attrib_info (
-		f,
-		f->root_gid,
-		attrib_idx,
-		attrib_name,
-		len_of_attrib_name,
-		attrib_type,
-		attrib_nelem );
-}
-
-/*!
-  \ingroup h5part_c_api_attrib
-
-  Reads an attribute bound to current time-step.
-
-  \return \c H5_SUCCESS or error code 
-*/
-h5_int64_t
-H5PartReadStepAttrib (
-	h5_file_t *f,			/*!< [in]  Handle to open file */
-	const char *attrib_name,	/*!< [in] Name of attribute to read */
-	void *attrib_value		/*!< [out] Value of attribute */
-	) {
-
-	SET_FNAME ( f, __func__ );
-
-	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
-		return h5_get_errno ( f );
-
-	return h5_read_attrib ( f, f->step_gid, attrib_name, attrib_value );
-}
-
-/*!
-  \ingroup h5part_c_api_attrib
-
-  Reads an attribute bound to file \c f.
-
-  \return \c H5_SUCCESS or error code 
-*/
-h5_int64_t
-H5PartReadFileAttrib ( 
-	h5_file_t *f,
-	const char *attrib_name,
-	void *attrib_value
-	) {
-
-	SET_FNAME ( f, __func__ );
-
-	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
-		return h5_get_errno ( f );
-
-	return h5_read_attrib ( f, f->root_gid, attrib_name, attrib_value );
-}
-
-
diff --git a/src/C/H5_attribs.c b/src/C/H5_attribs.c
new file mode 100644
index 0000000..f6366f7
--- /dev/null
+++ b/src/C/H5_attribs.c
@@ -0,0 +1,186 @@
+#include <string.h>
+
+#include "h5core/h5_core.h"
+#include "H5.h"
+
+/********************** attribute API ****************************************/
+
+/*!
+  \ingroup h5_attrib
+
+  Writes an attribute \c name with the string \c value to
+  the file root ("/").
+
+  \return	\c H5_SUCCESS or error code   
+*/
+h5_err_t
+H5WriteFileAttribString (
+	h5_file_t *const f,	/*!< [in] Handle to open file */
+	const char *name,	/*!< [in] Name of attribute to create */
+	const char *value	/*!< [in] Value of attribute */ 
+	) {
+
+	SET_FNAME( f, __func__ );
+
+   	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
+		return h5_get_errno( f );
+
+	return h5_write_attrib (
+		f,
+		H5_ATTRIB_FILE,
+		name,
+		H5T_NATIVE_CHAR,
+		value,
+		strlen(value) + 1 );
+}
+
+/*!
+  \ingroup h5_attrib
+
+  Writes an attribute \c name with the string \c value to
+  the current timestep.
+
+  \return	\c H5_SUCCESS or error code   
+*/
+h5_err_t
+H5WriteStepAttribString (
+	h5_file_t *const f,	/*!< [in] Handle to open file */
+	const char *name,	/*!< [in] Name of attribute to create */
+	const char *value	/*!< [in] Value of attribute */ 
+	) {
+
+	SET_FNAME ( f, __func__ );
+
+   	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
+		return h5_get_errno( f );
+
+	return h5_write_attrib (
+		f, 
+		H5_ATTRIB_STEP,
+		name,
+		H5T_NATIVE_CHAR,
+		value,
+		strlen(value) + 1 );
+}
+
+/*!
+  \ingroup h5_attrib
+
+  Gets the number of attributes in the file's root ("/").
+
+  \return	Number of attributes or error code.
+*/
+h5_int64_t
+H5GetNumFileAttribs (
+	h5_file_t *const f	/*!< [in] Handle to open file */
+	) {
+	SET_FNAME( f, __func__ );
+
+   	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
+		return h5_get_errno( f );
+
+	return h5_get_num_attribs ( f, H5_ATTRIB_FILE );
+}
+
+/*!
+  \ingroup h5_attrib
+
+  Gets the number of attributes bound to the current step.
+
+  \return	Number of attributes or error code.
+*/
+h5_int64_t
+H5GetNumStepAttribs (
+	h5_file_t *const f 	/*!< [in] Handle to open file */
+	) {
+	SET_FNAME( f, __func__ );
+
+   	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
+		return h5_get_errno( f );
+
+	return h5_get_num_attribs ( f, H5_ATTRIB_STEP );
+}
+
+
+/*!
+  \ingroup h5_attrib
+
+  Gets the name, type and number of elements of the file attribute
+  specified by its index.
+
+  This function can be used to retrieve all attributes bound to the
+  file \c f by looping from \c 0 to the number of attribute minus
+  one.  The number of attributes bound to file \c f can be queried
+  by calling the function \c H5GetNumFileAttribs().
+
+  \return	\c H5_SUCCESS or error code 
+*/
+
+h5_int64_t
+H5GetFileAttribInfo (
+	h5_file_t *const f,		/*!< [in]  Handle to open file */
+	const h5_int64_t attrib_idx,	/*!< [in]  Index of attribute to get
+					           infos about */
+	char *attrib_name,		/*!< [out] Name of attribute */
+	const h5_int64_t len_of_attrib_name,
+					/*!< [in]  length of buffer \c name */
+	h5_int64_t *attrib_type,	/*!< [out] Type of value. */
+	h5_int64_t *attrib_nelem	/*!< [out] Number of elements */
+	) {
+
+	SET_FNAME ( f, __func__ );
+
+	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
+		return h5_get_errno ( f );
+
+	return h5_get_attrib_info (
+		f,
+		H5_ATTRIB_FILE,
+		attrib_idx,
+		attrib_name,
+		len_of_attrib_name,
+		attrib_type,
+		attrib_nelem );
+}
+
+/*!
+  \ingroup h5_attrib
+
+  Gets the name, type and number of elements of the step attribute
+  specified by its index.
+
+  This function can be used to retrieve all attributes bound to the
+  current time-step by looping from \c 0 to the number of attribute
+  minus one.  The number of attributes bound to the current
+  time-step can be queried by calling the function
+  \c H5GetNumStepAttribs().
+
+  \return	\c H5_SUCCESS or error code 
+*/
+h5_int64_t
+H5GetStepAttribInfo (
+	h5_file_t *const f,		/*!< [in]  Handle to open file */
+	const h5_int64_t attrib_idx,	/*!< [in]  Index of attribute to
+					           get infos about */
+	char *attrib_name,		/*!< [out] Name of attribute */
+	const h5_int64_t len_of_attrib_name,
+					/*!< [in]  length of buffer \c name */
+	h5_int64_t *attrib_type,	/*!< [out] Type of value. */
+	h5_int64_t *attrib_nelem	/*!< [out] Number of elements */
+	) {
+	
+	SET_FNAME ( f, __func__ );
+
+   	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
+		return h5_get_errno( f );
+
+	return h5_get_attrib_info (
+		f,
+		H5_ATTRIB_STEP,
+		attrib_idx,
+		attrib_name,
+		len_of_attrib_name,
+		attrib_type,
+		attrib_nelem );
+}
+
diff --git a/src/C/Makefile.am b/src/C/Makefile.am
index 9e32dc1..d01b258 100644
--- a/src/C/Makefile.am
+++ b/src/C/Makefile.am
@@ -44,6 +44,7 @@ EXTRA_LIBRARIES = libH5.a
 # Header files that I wish to install in $(prefix)/include
 include_HEADERS =				\
 	../include/H5.h				\
+	../include/H5_attribs.h			\
 	../include/H5Block.h			\
 	../include/H5Fed.h			\
 	../include/H5Fed_store.h		\
@@ -56,6 +57,7 @@ EXTRA_HEADERS =
 # Listing of sources
 libH5_a_SOURCES =				\
 	H5.c					\
+	H5_attribs.c				\
 	H5_inquiry.c				\
 	H5Block.c				\
 	H5Fed.c					\
diff --git a/src/h5core/h5_attribs.c b/src/h5core/h5_attribs.c
index 5e7e55d..1d51486 100644
--- a/src/h5core/h5_attribs.c
+++ b/src/h5core/h5_attribs.c
@@ -1,11 +1,18 @@
 #include "h5_core.h"
 #include "h5_core_private.h"
 
-/*!
-  \ingroup h5_core
-  \defgroup h5_core_attrib	Attribute handling
+static h5_err_t
+_get_hdf5_obj_id(
+	h5_file_t *const f,
+	const char type,
+	hid_t *id
+	) {
+	if (type == H5_ATTRIB_FILE) *id = f->root_gid;
+	else if (type == H5_ATTRIB_STEP) *id = f->step_gid;
+	else h5_error(f, H5_ERR_INVAL, "Attibute flag not recognized");
+	return H5_SUCCESS;
+}
 
-*/
 /*!
   \ingroup h5_core_attrib
 
@@ -18,7 +25,7 @@
 h5_err_t
 h5_read_attrib (
 	h5_file_t* const f,		/*!< handle to open file */
-	const hid_t id,			/*!< id of HDF5 object */
+	const char type,		/*!< FILE or STEP flag */
 	const char* attrib_name,	/*!< name of HDF5 attribute to read */
 	void* const attrib_value	/*!< OUT: attribute value */
 	) {
@@ -28,6 +35,9 @@ h5_read_attrib (
 	hid_t mytype;
 	hsize_t nelem;
 
+	hid_t id;
+	TRY( _get_hdf5_obj_id(f, type, &id) );
+
 	TRY( attrib_id = h5priv_open_hdf5_attribute (f, id, attrib_name) );
 	TRY( mytype = h5priv_get_hdf5_attribute_type (f, attrib_id) );
 	TRY( space_id = h5priv_get_hdf5_attribute_dataspace (f, attrib_id) );
@@ -51,7 +61,7 @@ h5_read_attrib (
 h5_err_t
 h5_write_attrib (
 	h5_file_t* const f,		/*!< handle to open file */
-	const hid_t id,			/*!< id of HDF5 object */
+	const char type,		/*!< FILE or STEP flag */
 	const char* attrib_name,	/*!< name of HDF5 attribute to write */
 	const hid_t attrib_type,	/*!< HDF5 type of attribute */
 	const void* attrib_value,	/*!< value of attribute */
@@ -60,6 +70,9 @@ h5_write_attrib (
 	hid_t space_id;
 	hid_t attrib_id;
 
+	hid_t id;
+	TRY( _get_hdf5_obj_id(f, type, &id) );
+
 	TRY( space_id = h5priv_create_hdf5_dataspace (f, 1, &attrib_nelem, NULL) );
 	TRY( attrib_id = h5priv_create_hdf5_attribute ( 
 		      f,
@@ -86,7 +99,7 @@ h5_write_attrib (
 h5_err_t
 h5_get_attrib_info (
 	h5_file_t* const f,		/*!< handle to open file */
-	const hid_t id,			/*!< id of HDF5 object */
+	const char type,		/*!< FILE or STEP flag */
 	const h5_int64_t attrib_idx,	/*!< index of attribute */
 	char* attrib_name,		/*!< OUT: name of attribute */
 	const h5_int64_t len_attrib_name, /*!< buffer length */
@@ -97,6 +110,9 @@ h5_get_attrib_info (
 	hid_t mytype;
 	hid_t space_id;
 
+	hid_t id;
+	TRY( _get_hdf5_obj_id(f, type, &id) );
+
 	TRY( attrib_id = h5priv_open_hdf5_attribute_idx (
 		      f,
 		      id,
@@ -134,9 +150,12 @@ h5_get_attrib_info (
 */
 h5_ssize_t
 h5_get_num_attribs (
-	h5_file_t* f,		/*!< handle to open file */
-	const hid_t id
+	h5_file_t *const f,	/*!< handle to open file */
+	const char type		/*!< FILE or STEP flag */
 	) {
 	CHECK_FILEHANDLE (f);
+	hid_t id;
+	TRY( _get_hdf5_obj_id(f, type, &id) );
 	return h5priv_get_num_hdf5_attribute (f, id);
 }
+
diff --git a/src/h5core/h5_errorhandling.c b/src/h5core/h5_errorhandling.c
index d8508d0..08235b6 100644
--- a/src/h5core/h5_errorhandling.c
+++ b/src/h5core/h5_errorhandling.c
@@ -5,8 +5,8 @@
 #include "h5_core.h"
 #include "h5_core_private.h"
 
-static h5_errorhandler_t	h5priv_errhandler = h5_report_errorhandler;
-static h5_int32_t h5priv_debuglevel = 0;
+static h5_errorhandler_t	h5priv_errhandler	= h5_report_errorhandler;
+static h5_int32_t		h5priv_debug_level	= 0;
 
 /*!
   \ingroup h5_core
@@ -34,11 +34,11 @@ const char* const H5_O_MODES[] = {
   \return \c H5_ERR_INVAL if debug level is invalid.
 */
 h5_err_t
-h5_set_debuglevel (
-	h5_id_t debuglevel	/*!< debug level */
+h5_set_debug_level (
+	const h5_id_t level	/*!< debug level */
 	) {
-	if (debuglevel < 0 || debuglevel > 5) return H5_ERR_INVAL;
-	h5priv_debuglevel = debuglevel;
+	if (level < 0 || level > 5) return H5_ERR_INVAL;
+	h5priv_debug_level = level;
 	return H5_SUCCESS;
 }
 
@@ -50,10 +50,10 @@ h5_set_debuglevel (
   \return current debug level
 */
 h5_id_t
-h5_get_debuglevel (
+h5_get_debug_level (
 	void
 	) {
-	return h5priv_debuglevel;
+	return h5priv_debug_level;
 }
 
 /*!
@@ -65,7 +65,7 @@ h5_get_debuglevel (
 */
 h5_err_t
 h5_set_errorhandler (
-	h5_errorhandler_t handler
+	const h5_errorhandler_t handler
 	) {
 	h5priv_errhandler = handler;
 	return H5_SUCCESS;
@@ -94,7 +94,7 @@ h5_get_errorhandler (
 */
 h5_err_t
 h5_get_errno (
-	h5_file_t* const f
+	const h5_file_t* const f
 	) {
 	return f->__errno;
 }
@@ -109,9 +109,9 @@ h5_get_errno (
 void
 h5_set_errno (
 	h5_file_t* const f,
-	h5_err_t h5_errno
+	const h5_err_t errno
 	) {
-	f->__errno = h5_errno;
+	f->__errno = errno;
 }
 
 
@@ -125,12 +125,12 @@ h5_set_errno (
 */
 h5_err_t
 h5_report_errorhandler (
-	h5_file_t* const f,
+	const h5_file_t* const f,
 	const char* fmt,
 	va_list ap
 	) {
 
-	if (h5priv_debuglevel > 0) {
+	if (h5priv_debug_level > 0) {
 		h5_verror (f, fmt, ap);
 	}
 	return f->__errno;
@@ -144,12 +144,12 @@ h5_report_errorhandler (
 */
 h5_err_t
 h5_abort_errorhandler (
-	h5_file_t* const f,
+	const h5_file_t* const f,
 	const char* fmt,
 	va_list ap
 	) {
 
-	if (h5priv_debuglevel > 0) {
+	if (h5priv_debug_level > 0) {
 		h5_verror (f, fmt, ap);
 	}
 	exit (-(int)f->__errno);
@@ -183,7 +183,7 @@ _vprintf (
 h5_err_t
 h5_error (
 	h5_file_t* const f,
-	h5_err_t __errno,
+	const h5_err_t __errno,
 	const char* fmt,
 	...
 	) {
@@ -204,12 +204,12 @@ h5_error (
 */
 void
 h5_verror (
-	h5_file_t* const f,
+	const h5_file_t* const f,
 	const char* fmt,
 	va_list ap
 	) {
 
-	if (h5priv_debuglevel < 1) return;
+	if (h5priv_debug_level < 1) return;
 	_vprintf (stderr, "E", f->__funcname, fmt, ap);
 }
 
@@ -221,11 +221,11 @@ h5_verror (
 */
 void
 h5_vwarn (
-	h5_file_t* const f,
+	const h5_file_t* const f,
 	const char* fmt,
 	va_list ap
 	) {
-	if (h5priv_debuglevel < 2) return;
+	if (h5priv_debug_level < 2) return;
 	_vprintf (stderr, "W", f->__funcname, fmt, ap);
 }
 
@@ -236,8 +236,8 @@ h5_vwarn (
 */
 void
 h5_warn (
-h5_file_t* const f,
-		const char* fmt,
+	const h5_file_t* const f,
+	const char* fmt,
 	...
 	) {
 	va_list ap;
@@ -253,11 +253,11 @@ h5_file_t* const f,
 */
 void
 h5_vinfo (
-	h5_file_t* const f,
+	const h5_file_t* const f,
 	const char* fmt,
 	va_list ap
 	) {
-	if (h5priv_debuglevel < 3) return;
+	if (h5priv_debug_level < 3) return;
 	_vprintf (stdout, "I", f->__funcname, fmt, ap);
 }
 
@@ -268,7 +268,7 @@ h5_vinfo (
 */
 void
 h5_info (
-	h5_file_t* const f,
+	const h5_file_t* const f,
 	const char* fmt,
 	...
 	) {
@@ -285,11 +285,11 @@ h5_info (
 */
 void
 h5_vdebug (
-	h5_file_t* const f,
+	const h5_file_t* const f,
 	const char* fmt,
 	va_list ap
 	) {
-	if (h5priv_debuglevel < 4) return;
+	if (h5priv_debug_level < 4) return;
 	_vprintf (stdout, "D", f->__funcname, fmt, ap);
 }
 
@@ -300,7 +300,7 @@ h5_vdebug (
 */
 void
 h5_debug (
-	h5_file_t* const f,
+	const h5_file_t* const f,
 	const char* fmt,
 	...
 	) {
@@ -330,7 +330,7 @@ h5_set_funcname (
 */
 const char*
 h5_get_funcname (
-	h5_file_t* const f
+	const h5_file_t* const f
 	) {
 	return f->__funcname;
 }
diff --git a/src/h5core/h5_hdf5.c b/src/h5core/h5_hdf5.c
index 6db8e70..874c39f 100644
--- a/src/h5core/h5_hdf5.c
+++ b/src/h5core/h5_hdf5.c
@@ -812,9 +812,9 @@ h5priv_get_hdf5_mdc_property (
 h5_err_t
 h5priv_set_hdf5_alignment_property (
 	h5_file_t* const f,
-	hid_t fapl_id,
-	hsize_t threshold,
-	hsize_t alignment
+	const hid_t fapl_id,
+	const hsize_t threshold,
+	const hsize_t alignment
 	) {
 	herr_t herr = H5Pset_alignment (fapl_id, threshold, alignment);
 	if (herr < 0)
@@ -826,6 +826,22 @@ h5priv_set_hdf5_alignment_property (
 	return H5_SUCCESS;
 }
 
+h5_err_t
+h5priv_set_hdf5_btree_ik_property (
+	h5_file_t* const f,
+	const hid_t fcpl_id,
+	const hsize_t btree_ik
+	) {
+	herr_t herr = H5Pset_istore_k (fcpl_id, btree_ik);
+	if (herr < 0)
+		h5_error (
+			f,
+			H5_ERR_HDF5,
+			"Cannot set btree size in the "
+			"file access property list.");
+	return H5_SUCCESS;
+}
+
 h5_err_t
 h5priv_close_hdf5_property (
 	h5_file_t* const f,
diff --git a/src/h5core/h5_hdf5_private.h b/src/h5core/h5_hdf5_private.h
index 23f492b..490d4f5 100644
--- a/src/h5core/h5_hdf5_private.h
+++ b/src/h5core/h5_hdf5_private.h
@@ -272,9 +272,16 @@ h5priv_get_hdf5_mdc_property (
 h5_err_t
 h5priv_set_hdf5_alignment_property (
 	h5_file_t* const f,
-	hid_t fapl_id,
-	hsize_t threshold,
-	hsize_t alignment
+	const hid_t fapl_id,
+	const hsize_t threshold,
+	const hsize_t alignment
+	);
+
+h5_err_t
+h5priv_set_hdf5_btree_ik_property (
+	h5_file_t* const f,
+	const hid_t fcpl_id,
+	const hsize_t btree_ik
 	);
 
 h5_err_t
diff --git a/src/h5core/h5_mpi.c b/src/h5core/h5_mpi.c
index e657d7c..c084c95 100644
--- a/src/h5core/h5_mpi.c
+++ b/src/h5core/h5_mpi.c
@@ -5,7 +5,7 @@
 
 h5_err_t
 h5priv_mpi_recv(
-	h5_file_t *f,
+	h5_file_t *const f,
 	void* buf,
 	const int count,
 	const MPI_Datatype type,
@@ -54,7 +54,7 @@ h5_err_t
 h5priv_mpi_sum (
 	h5_file_t* const f,
 	void* sendbuf,
-        void* recvbuf,
+	void* recvbuf,
 	const int count,
 	const MPI_Datatype type,
 	const MPI_Comm comm
@@ -76,7 +76,7 @@ h5_err_t
 h5priv_mpi_prefix_sum (
 	h5_file_t* const f,
 	void* sendbuf,
-        void* recvbuf,
+	void* recvbuf,
 	const int count,
 	const MPI_Datatype type,
 	const MPI_Comm comm
diff --git a/src/h5core/h5_openclose.c b/src/h5core/h5_openclose.c
index 5c665eb..de0a2d6 100644
--- a/src/h5core/h5_openclose.c
+++ b/src/h5core/h5_openclose.c
@@ -191,10 +191,14 @@ h5priv_open_file (
 // set alignment
 	lov_user_md lum;
 	llapi_file_get_stripe(filename, &lum);
-	h5_size_t stripe_size = (h5_size_t)lum.lmm_stripe_size;
-	h5info(f, "Found lustre stripe size of %llu bytes", stripe_size);
+	hsize_t stripe_size = (hsize_t)lum.lmm_stripe_size;
+	h5info(f, "Found lustre stripe size of %lld bytes", (long long)stripe_size);
 	TRY( h5priv_set_hdf5_alignment_property(f,
 				f->access_prop, 0, stripe_size) );
+	hsize_t btree_ik = (stripe_size - 4096) / 96;
+	hsize_t btree_bytes = 64 + 96*btree_ik;
+	h5info(f, "Using %lld bytes for HDF5 btree", (long long)btree_bytes);
+	TRY( h5priv_set_hdf5_btree_ik_property(f, f->create_prop, btree_ik) );
 #endif
 
 	if (flags & H5_O_RDONLY) {
diff --git a/src/h5core/h5_readwrite.c b/src/h5core/h5_readwrite.c
index a0c4225..ea01738 100644
--- a/src/h5core/h5_readwrite.c
+++ b/src/h5core/h5_readwrite.c
@@ -280,15 +280,15 @@ h5_get_dataset_type(
 	return type;
 }
 
-h5_int64_t
+h5_err_t
 h5_has_index (
-	h5_file_t* const f,    	/*!< [in]  Handle to open file */
-	h5_int64_t step	       	/*!< [in]  Step number to query */
+	h5_file_t* const f,		/*!< [in]  Handle to open file */
+	const h5_int64_t step	/*!< [in]  Step number to query */
 	) {
-	char name[128];
+	char name[2*H5_STEPNAME_LEN];
 	sprintf (name,
-		 "%s#%0*lld",
-		 f->prefix_step_name, f->width_step_idx, (long long)step);
+		"%s#%0*lld",
+		f->prefix_step_name, f->width_step_idx, (long long)step);
 	return (H5Gget_objinfo(f->file, name, 1, NULL) >= 0);
 }
 
@@ -305,14 +305,14 @@ h5_normalize_dataset_name (
 		strcpy ( name2, name );
 	}
 
-        return H5_SUCCESS;
+	return H5_SUCCESS;
 }
 
 #ifdef PARALLEL_IO
 h5_err_t
 h5_set_throttle (
-	h5_file_t* f,
-	int factor
+	h5_file_t* const f,
+	const int factor
 	) {
 	if ( (f->mode & H5_VFD_INDEPENDENT) || (f->mode & H5_VFD_MPIPOSIX) ) {
 		f->throttle = factor;
@@ -329,7 +329,7 @@ h5_set_throttle (
 
 h5_err_t
 h5_start_throttle (
-	h5_file_t *f
+	h5_file_t* const f
 	) {
 
 	if (f->throttle > 0) {
@@ -358,7 +358,7 @@ h5_start_throttle (
 
 h5_err_t
 h5_end_throttle (
-	h5_file_t *f
+	h5_file_t* const f
 	) {
 
 	if (f->throttle > 0) {
diff --git a/src/h5core/h5u_model.c b/src/h5core/h5u_model.c
index 3018f40..a526b61 100644
--- a/src/h5core/h5u_model.c
+++ b/src/h5core/h5u_model.c
@@ -3,7 +3,7 @@
 
 h5_int64_t
 h5u_get_num_particles (
-	h5_file_t *f			/*!< [in]  Handle to open file */
+	h5_file_t *const f      /*!< [in]  Handle to open file */
 	) {
 	h5_int64_t nparticles;
 	ssize_t exists;
@@ -72,13 +72,11 @@ h5u_get_num_particles (
 	return nparticles;
 }
 
-
-
 h5_int64_t
 h5u_set_num_particles (
-	h5_file_t *f,			/*!< [in] Handle to open file */
-	h5_int64_t nparticles,	/*!< [in] Number of particles */
-	h5_int64_t stride		/*!< [in] Stride of particles in memory */
+	h5_file_t *const f,		/*!< [in] Handle to open file */
+	const h5_int64_t nparticles,	/*!< [in] Number of particles */
+	const h5_int64_t stride		/*!< [in] Stride of particles in memory */
 	) {
 	CHECK_FILEHANDLE( f );
 	struct h5u_fdata *u = f->u;
@@ -200,14 +198,14 @@ h5u_set_num_particles (
 
 h5_int64_t
 h5u_has_view (
-	h5_file_t *f
+	const h5_file_t *const f
 	) {
 	return  ( f->u->viewindexed || ( f->u->viewstart >= 0 && f->u->viewend >= 0 ));
 }
 
 h5_err_t
 h5u_reset_view (
-	h5_file_t *f
+	h5_file_t *const f
 	) {	     
 
 	struct h5u_fdata *u = f->u;
@@ -225,9 +223,9 @@ h5u_reset_view (
 
 h5_err_t
 h5u_set_view (
-	h5_file_t *f,			/*!< [in]  Handle to open file */
+	h5_file_t *const f,		/*!< [in]  Handle to open file */
 	h5_int64_t start,		/*!< [in]  Start particle */
-	h5_int64_t end		/*!< [in]  End particle */
+	h5_int64_t end	        	/*!< [in]  End particle */
 	) {
 
 	h5_int64_t herr = 0;
@@ -308,9 +306,9 @@ h5u_set_view (
 
 h5_int64_t
 h5u_set_view_indices (
-	h5_file_t *f,			/*!< [in]  Handle to open file */
-	const h5_int64_t *indices,	/*!< [in]  List of indices */
-	h5_int64_t nelems		/*!< [in]  Size of list */
+	h5_file_t *const f,	        	/*!< [in]  Handle to open file */
+	const h5_int64_t *const indices,	/*!< [in]  List of indices */
+	const h5_int64_t nelems		        /*!< [in]  Size of list */
 	) {
 
 	hsize_t total;
@@ -375,7 +373,7 @@ h5u_set_view_indices (
 
 h5_int64_t 
 h5u_get_view (
-	h5_file_t *f,
+	h5_file_t *const f,
 	h5_int64_t *start,
 	h5_int64_t *end
 	) {
@@ -410,7 +408,7 @@ h5u_get_view (
 
 h5_int64_t
 h5u_set_canonical_view (
-	h5_file_t *f
+	h5_file_t *const f
 	) {
 	TRY( h5u_reset_view ( f ) );
 
@@ -448,7 +446,7 @@ h5u_set_canonical_view (
 
 h5_int64_t
 h5u_get_num_datasets (
-	h5_file_t *f		/*!< [in]  Handle to open file */
+	h5_file_t *const f		/*!< [in]  Handle to open file */
 	) {
 	ssize_t n;
 	TRY ( n = h5_get_num_hdf5_datasets(f, f->step_gid ) );
@@ -460,8 +458,8 @@ h5u_get_num_datasets (
  */
 h5_int64_t
 h5u_get_dataset_info (
-	h5_file_t *f,		/*!< [in]  Handle to open file */
-	const h5_int64_t idx,/*!< [in]  Index of the dataset */
+	h5_file_t *const f,	/*!< [in]  Handle to open file */
+	const h5_int64_t idx,   /*!< [in]  Index of the dataset */
 	char *dataset_name,	/*!< [out] Name of dataset */
 	const h5_int64_t len_dataset_name,
 				/*!< [in]  Size of buffer \c dataset_name */
@@ -493,8 +491,8 @@ h5u_get_dataset_info (
 
 h5_err_t
 h5u_set_chunk (
-        h5_file_t *f,
-        h5_size_t size
+        h5_file_t *const f,
+        const h5_size_t size
         ) {
 
 	if ( f->u->dcreate_prop == H5P_DEFAULT ) {
diff --git a/src/include/H5_attribs.h b/src/include/H5_attribs.h
new file mode 100644
index 0000000..22ff1f8
--- /dev/null
+++ b/src/include/H5_attribs.h
@@ -0,0 +1,48 @@
+h5_err_t
+H5WriteFileAttribString (
+	h5_file_t *const f,	/*!< [in] Handle to open file */
+	const char *name,	/*!< [in] Name of attribute to create */
+	const char *value	/*!< [in] Value of attribute */ 
+	);
+
+h5_err_t
+H5WriteStepAttribString (
+	h5_file_t *const f,	/*!< [in] Handle to open file */
+	const char *name,	/*!< [in] Name of attribute to create */
+	const char *value	/*!< [in] Value of attribute */ 
+	);
+
+h5_int64_t
+H5GetNumFileAttribs (
+	h5_file_t *const f	/*!< [in] Handle to open file */
+	);
+
+h5_int64_t
+H5GetNumStepAttribs (
+	h5_file_t *const f 	/*!< [in] Handle to open file */
+	);
+
+h5_int64_t
+H5GetFileAttribInfo (
+	h5_file_t *const f,		/*!< [in]  Handle to open file */
+	const h5_int64_t attrib_idx,	/*!< [in]  Index of attribute to get
+					           infos about */
+	char *attrib_name,		/*!< [out] Name of attribute */
+	const h5_int64_t len_of_attrib_name,
+					/*!< [in]  length of buffer \c name */
+	h5_int64_t *attrib_type,	/*!< [out] Type of value. */
+	h5_int64_t *attrib_nelem	/*!< [out] Number of elements */
+	);
+
+h5_int64_t
+H5GetStepAttribInfo (
+	h5_file_t *const f,		/*!< [in]  Handle to open file */
+	const h5_int64_t attrib_idx,	/*!< [in]  Index of attribute to
+					           get infos about */
+	char *attrib_name,		/*!< [out] Name of attribute */
+	const h5_int64_t len_of_attrib_name,
+					/*!< [in]  length of buffer \c name */
+	h5_int64_t *attrib_type,	/*!< [out] Type of value. */
+	h5_int64_t *attrib_nelem	/*!< [out] Number of elements */
+	);
+
diff --git a/src/include/h5core/h5_attribs.h b/src/include/h5core/h5_attribs.h
index 02571af..62c6ae0 100644
--- a/src/include/h5core/h5_attribs.h
+++ b/src/include/h5core/h5_attribs.h
@@ -1,10 +1,13 @@
 #ifndef __H5_ATTRIBS_H
 #define __H5_ATTRIBS_H
 
+#define H5_ATTRIB_FILE 0
+#define H5_ATTRIB_STEP 1
+
 h5_int64_t
 h5_read_attrib (
 	h5_file_t * const f,
-	hid_t id,
+	const char type,
 	const char *attrib_name,
 	void *attrib_value
 	);
@@ -12,7 +15,7 @@ h5_read_attrib (
 h5_int64_t
 h5_write_attrib (
 	h5_file_t * const f,
-	hid_t id,
+	const char type,
 	const char *attrib_name,
 	const hid_t attrib_type,
 	const void *attrib_value,
@@ -21,8 +24,8 @@ h5_write_attrib (
 
 h5_int64_t
 h5_get_attrib_info (
-	h5_file_t * const f,
-	hid_t id,
+	h5_file_t *const f,
+	const char type,
 	const h5_int64_t attrib_idx,
 	char *attrib_name,
 	const h5_int64_t len_attrib_name,
@@ -32,8 +35,8 @@ h5_get_attrib_info (
 
 h5_ssize_t
 h5_get_num_attribs (
-	h5_file_t * constf,
-	hid_t id
+	h5_file_t *const f,
+	const char type
 	);
 
 #endif
diff --git a/src/include/h5core/h5_errorhandling.h b/src/include/h5core/h5_errorhandling.h
index 07aeab8..26fb422 100644
--- a/src/include/h5core/h5_errorhandling.h
+++ b/src/include/h5core/h5_errorhandling.h
@@ -44,18 +44,18 @@
 
 
 h5_err_t
-h5_set_debuglevel (
-	h5_id_t debuglevel
+h5_set_debug_level (
+	const h5_id_t level
 	);
 
 h5_err_t
-h5_get_debuglevel (
+h5_get_debug_level (
 	void
 	);
 
 h5_err_t
 h5_set_errorhandler (
-	h5_errorhandler_t errorhandler
+	const h5_errorhandler_t errorhandler
 	);
 
 h5_errorhandler_t
@@ -65,33 +65,33 @@ h5_get_errorhandler (
 
 h5_err_t
 h5_get_errno (
-	h5_file_t * const f
+	const h5_file_t * const f
 	);
 
 void
 h5_set_errno (
 	h5_file_t * const f,
-	h5_err_t h5_errno
+	const h5_err_t h5_errno
 	);
 
 h5_err_t
 h5_report_errorhandler (
-	h5_file_t * const f,
+	const h5_file_t * const f,
 	const char *fmt,
 	va_list ap
 	);
 
 h5_err_t
 h5_abort_errorhandler (
-	h5_file_t * const f,
+	const h5_file_t * const f,
 	const char *fmt,
 	va_list ap
-	) ;
+	);
 
 h5_err_t
 h5_error (
 	h5_file_t * const f,
-	h5_err_t error_no,
+	const h5_err_t error_no,
 	const char *fmt,
 	...
 	)
@@ -102,21 +102,21 @@ h5_error (
 
 void
 h5_verror (
-	h5_file_t * const f,
+	const h5_file_t * const f,
 	const char *fmt,
 	va_list ap
 	);
 
 void
 h5_vwarn (
-	h5_file_t * const f,
+	const h5_file_t * const f,
 	const char *fmt,
 	va_list ap
 	);
 
 void
 h5_warn (
-	h5_file_t * const f,
+	const h5_file_t * const f,
 	const char *fmt,
 	...
 	)
@@ -127,14 +127,14 @@ __attribute__ ((format (printf, 2, 3)))
 
 void
 h5_vinfo (
-	h5_file_t * const f,
+	const h5_file_t * const f,
 	const char *fmt,
 	va_list ap
 	);
 
 void
 h5_info (
-	h5_file_t * const f,
+	const h5_file_t * const f,
 	const char *fmt,
 	...
 	)
@@ -145,14 +145,14 @@ __attribute__ ((format (printf, 2, 3)))
 
 void
 h5_vdebug (
-	h5_file_t * const f,
+	const h5_file_t * const f,
 	const char *fmt,
 	va_list ap
 	);
 
 void
 h5_debug (
-	h5_file_t * const f,
+	const h5_file_t * const f,
 	const char *fmt,
 	...
 	)
@@ -169,7 +169,7 @@ h5_set_funcname (
 
 const char *
 h5_get_funcname (
-	h5_file_t * const f
+	const h5_file_t * const f
 	);
 
 #endif
diff --git a/src/include/h5core/h5_types.h b/src/include/h5core/h5_types.h
index a258af8..36e5477 100644
--- a/src/include/h5core/h5_types.h
+++ b/src/include/h5core/h5_types.h
@@ -57,7 +57,7 @@ struct h5_file;
 typedef struct h5_file h5_file_t;
 
 typedef h5_err_t (*h5_errorhandler_t)(
-	struct h5_file * const,
+	const struct h5_file * const,
 	const char*,
 	va_list ap );
 
diff --git a/src/include/h5core/h5u_model.h b/src/include/h5core/h5u_model.h
index 5514758..eb10fda 100644
--- a/src/include/h5core/h5u_model.h
+++ b/src/include/h5core/h5u_model.h
@@ -3,60 +3,60 @@
 
 h5_int64_t
 h5u_get_num_particles (
-	h5_file_t *f
+	h5_file_t *const f
 	);
 
 h5_int64_t
 h5u_set_num_particles (
-	h5_file_t *f,
-	h5_int64_t nparticles,
-	h5_int64_t stride
+	h5_file_t *const f,
+	const h5_int64_t nparticles,
+	const h5_int64_t stride
 	);
 
 h5_int64_t
 h5u_has_view (
-	h5_file_t *f
+	const h5_file_t *const f
 	);
 
 h5_int64_t
 h5u_reset_view (
-	h5_file_t *f
+	h5_file_t *const f
 	);
 
 h5_int64_t
 h5u_set_view (
-	h5_file_t *f,
+	h5_file_t *const f,
 	h5_int64_t start,
 	h5_int64_t end
 	);
 
 h5_int64_t
 h5u_set_view_indices (
-	h5_file_t *f,
-	const h5_int64_t *indices,
-	h5_int64_t nelems
+	h5_file_t *const f,
+	const h5_int64_t *const indices,
+	const h5_int64_t nelems
 	);
 
 h5_int64_t 
 h5u_get_view (
-	h5_file_t *f,
+	h5_file_t *const f,
 	h5_int64_t *start,
 	h5_int64_t *end
 	);
 
 h5_int64_t
 h5u_set_canonical_view (
-	h5_file_t *f
+	h5_file_t *const f
 	);
 
 h5_int64_t
 h5u_get_num_datasets (
-	h5_file_t *f
+	h5_file_t *const f
 	);
 
 h5_int64_t
 h5u_get_dataset_info (
-	h5_file_t *f,
+	h5_file_t *const f,
 	const h5_int64_t idx,
 	char *dataset_name,
 	const h5_int64_t len_dataset_name,
@@ -66,8 +66,8 @@ h5u_get_dataset_info (
 
 h5_err_t
 h5u_set_chunk (
-        h5_file_t *f,
-        h5_size_t size
+        h5_file_t *const f,
+        const h5_size_t size
         );
 
 #endif