From Sam Rushing's Medusa, via SF patch #100858: add & document
os.seteuid(), os.setegid(), os.setreuid(), os.setregid().
diff --git a/Doc/lib/libos.tex b/Doc/lib/libos.tex
index 55db0e1..803d90b 100644
--- a/Doc/lib/libos.tex
+++ b/Doc/lib/libos.tex
@@ -181,6 +181,16 @@
 actually preferable to assign to items of \code{os.environ}.  
 \end{funcdesc}
 
+\begin{funcdesc}{setegid}{egid}
+Set the current process's effective group id.
+Availability: \UNIX{}.
+\end{funcdesc}
+
+\begin{funcdesc}{seteuid}{euid}
+Set the current process's effective user id.
+Availability: \UNIX{}.
+\end{funcdesc}
+
 \begin{funcdesc}{setgid}{gid}
 Set the current process' group id.
 Availability: \UNIX{}.
@@ -199,6 +209,16 @@
 Availability: \UNIX{}.
 \end{funcdesc}
 
+\begin{funcdesc}{setreuid}{ruid, euid}
+Set the current process's real and effective user ids.
+Availability: \UNIX{}.
+\end{funcdesc}
+
+\begin{funcdesc}{setregid}{rgid, egid}
+Set the current process's real and effective group ids.
+Availability: \UNIX{}.
+\end{funcdesc}
+
 \begin{funcdesc}{setsid}{}
 Calls the system call \cfunction{setsid()}.  See the \UNIX{} manual
 for the semantics.