HDF5 documents and links Introduction to HDF5 HDF5 Reference Manual HDF5 User's Guide for Release 1.6 | And in this document, the HDF5 User's Guide from Release 1.4.5: Files Datasets Datatypes Dataspaces Groups References Attributes Property Lists Error Handling Filters Caching Chunking Mounting Files Performance Debugging Environment DDL

# HDF5 Library Environment Variables and Configuration Parameters

## 1. Environment Variables

The HDF5 library uses UNIX environment variables to control or adjust certain library features at runtime. The variables and their defined effects are as follows:

`HDF5_DEBUG`
  Defines a list of debugging switches documented in the Debugging section of the HDF5 User's Guide.
`HDF5_NOCLEANUP`
  When set to a non-empty value, the programs in the test directory do not remove temporary HDF5 data files. The default is for each test to remove the files before exit.
`HDF5_DISABLE_VERSION_CHECK`
  When set to `1`, HDF5 will not abort when the version of the HDF5 headers doesn't match the version of the HDF5 library.
`HDF5_MPI_OPT_TYPES` (for parallel beta version only)
  When set to `1`, PHDF5 will use the MPI optimized code to perform parallel read/write accesses to datasets. Currently, this optimization fails when accessing extendable datasets. The default is not to use the optimized code.

## 2. Configuration Parameters

The HDF5 configuration script accepts a list of parameters to control configuration features when creating the Makefiles for the library. The command
`configure --help`
will display the current list of parameters and their effects.

HDF5 documents and links Introduction to HDF5 HDF5 Reference Manual HDF5 User's Guide for Release 1.6 | And in this document, the HDF5 User's Guide from Release 1.4.5: Files Datasets Datatypes Dataspaces Groups References Attributes Property Lists Error Handling Filters Caching Chunking Mounting Files Performance Debugging Environment DDL

Last modified: 13 December 1999