Routines (alphabetical) > Routines: H > HDF5 Routines > H5_LIST

# H5_LIST

The H5_LIST routine lists all of the groups and datasets found in an HDF5 file. This works in a manner similar to the HDF5 tool "h5dump". When calling H5_LIST, IDL prints the output directly to the console unless you specify the OUTPUT keyword.

The output from H5_LIST is a 3xN string array, the first element in each line lists the type of HDF5 object (i.e., "group", or "dataset"). The second element is the full identifier to the object. This identifier can be passed to H5_GETDATA to retrieve the data. The third element gives a description of the type and size of the dataset, or in the case of a group, a null string.

## Examples

In the first example, we locate an HDF5 file and ask IDL to return its group and dataset information.

file = FILEPATH('hdf5_test.h5', $

SUBDIRECTORY=['examples','data'])

H5_LIST, file

IDL returns:

In this example, we narrow down the output from the H5_LIST command by applying a filter that checks for IDs that contain "palette":

H5_LIST, file, FILTER='palette'

IDL displays:

## Syntax

H5_LIST, Filename, [, FILTER=value], [, OUTPUT=variable]

## Arguments

### Filename

A string denoting the name of the HDF5 file for which IDL will create the listing.

## Keywords

### FILTER

A string used for filtering the results. IDL applies the filter to the ID string of each item returned. IDL returns only those IDs that contain the filter string in the result. You may use wildcards (i.e., "*") between strings (e.g., "group1*foo").

Note: As HDF5 is case sensitive, the filter string is also case sensitive.

### OUTPUT

If set to a named variable, IDL assigns the string array to that variable and the results will not be printed to the screen.

## Version History

8.3 | Introduced

## See Also

H5_GETDATA, H5_PUTDATA