Provided by: systemtap-doc_2.3-1ubuntu1.4_all 

NAME
function::task_egid - The effective group identifier of the task
SYNOPSIS
task_egid:long(task:long)
ARGUMENTS
task
task_struct pointer
DESCRIPTION
This function returns the effective group id of the given task.
SystemTap Tapset Reference March 2016 FUNCTION::TASK_EGID(3stap)