# HG changeset patch
# User Christian Urban <christian dot urban at kcl dot ac dot uk>
# Date 1413730956 -3600
# Node ID bf45386496195daac29d9b042fded938f41e57d5
# Parent  31a749eba8c10ea8e40fad178b379d86393e831e
updated hw

diff -r 31a749eba8c1 -r bf4538649619 hws/hw04.pdf
Binary file hws/hw04.pdf has changed
diff -r 31a749eba8c1 -r bf4538649619 hws/hw04.tex
--- a/hws/hw04.tex	Sun Oct 19 14:00:28 2014 +0100
+++ b/hws/hw04.tex	Sun Oct 19 16:02:36 2014 +0100
@@ -1,7 +1,5 @@
 \documentclass{article}
-\usepackage{charter}
-\usepackage{hyperref}
-\usepackage{amssymb}
+\usepackage{../style}
 
 \begin{document}
 
@@ -30,6 +28,15 @@
 \item With which permissions does the program \texttt{login}
 normally have and why is this needed?
 
+\item The variable \texttt{PATH} is a shell variable in UNIX which
+  lists all directories that should be automatically searched for a
+  program. For example if \texttt{PATH} contains the directory
+  \texttt{/usr/bin} and the program \texttt{ls} is stored there, then
+  a user does not need to type \texttt{/usr/bin/ls} to run this file,
+  but \texttt{ls} suffices. The question is why is it a bad idea in
+  general, but in particular for root, to have \texttt{.} as the first
+  entry in ones variable \texttt{PATH}?
+
 \item A Unix directory might look as follows:
 
 \begin{center}