uid:group_data/3

Availability::- use_module(library(uid)).(can be autoloaded)

Source

group_data(?Field, ?GroupData, ?Value)

Value is the value for Field GroupData. Defined fields are:

name: Name of the user
password: Password hash of the user (or x if this is not accessible)
gid: Numeric group id of the group
members: List of user-names that are member of this group.