getgroups.2: Add NOTES explaining 32-bit system calls added in Linux 2.4

diff --git a/man2/getgroups.2 b/man2/getgroups.2
index 9851c87077fca74c1b31c8a8fbce9a56c5a49aaa..39f50946ba104c8eb0cc094a52b58f6b4d8f2350 100644 (file)
--- a/man2/getgroups.2
+++ b/man2/getgroups.2
@@ -28,7 +28,7 @@
 .\" 2008-05-03, mtk, expanded and rewrote parts of DESCRIPTION and RETURN
 .\"     VALUE, made style of page more consistent with man-pages style.
 .\"
-.TH GETGROUPS 2 2008-06-03 "Linux" "Linux Programmer's Manual"
+.TH GETGROUPS 2 2010-11-22 "Linux" "Linux Programmer's Manual"
 .SH NAME
 getgroups, setgroups \- get/set list of supplementary group IDs
 .SH SYNOPSIS
@@ -158,6 +158,16 @@ The maximum number of supplementary group IDs can be found using
 The maximum return value of
 .BR getgroups ()
 cannot be larger than one more than this value.
+
+The original Linux
+.BR getgroups ()
+system call supported only 16-bit group IDs.
+Subsequently, Linux 2.4 added 
+.BR getgroups32 (),
+supporting 32-bit IDs.
+The glibc
+.BR getgroups ()
+wrapper function transparently deals with the variation across kernel versions.
 .SH "SEE ALSO"
 .BR getgid (2),
 .BR setgid (2),