man mplist_put () - Set the value of a property in a property list.
NAME
mplist_put - Set the value of a property in a property list.
SYNOPSIS
MPlist* mplist_put (MPlist * plist, MSymbol key, void * val)
DESCRIPTION
The mplist_put() function searches property list plist from the beginning for a property whose key is key. If such a property is found, its value is changed to value. Otherwise, a new property whose key is key and value is value is appended at the end of plist. See the documentation of mplist_add() for the restriction on key and val.
If key is a managing key, val must be a managed object. In this case, the reference count of the old value, if not NULL, is decremented by one, and that of val is incremented by one.
RETURN VALUE
If the operation was successful, mplist_put() returns a sublist of plist whose first element is the just modified or added one. Otherwise, it returns NULL.