wvh_list_element

Retrieves a PV-WAVE variable handle for a copy of a LIST element at the specified index.

C Usage

WVH wvh_list_element( list_wvh, index)

WVH list_wvh

int index

Input Parameters

list_wvh—A PV-WAVE variable handle for the LIST containing the element you wish to retrieve.

index—The index of the LIST element you wish to retrieve.

Returned Values

Success: Returns a WVH for a PV-WAVE variable which is a copy of the element specified.

Failure: Returns NULL.

Discussion

The PV-WAVE LIST variable you pass in must already exist in your PV‑WAVE session, either retrieved by your C routine or created by wave_assign_list.

The wvh_list_element routine returns a WVH for a new PV-WAVE variable which is a copy of the specified LIST element. You may use any of the wvh_* routines to query or modify this variable. Modifying this variable does not affect the original LIST element. If you wish to modify the LIST itself, modify the returned WVH and use wvh_list_replace to place the modified variable in the LIST.

wvh_list_element currently supports only the C language interface.

For more information and example usage, see the example OPI in the $WAVE_DIR/demo/interapp/option directory.

For more general information about creating PV-WAVE variables in your C routine, see the documentation for the wave_assign_* routines.