hws/hw04.tex
changeset 250 bf4538649619
parent 247 95e14b2dbc94
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     1 \documentclass{article}
     1 \documentclass{article}
     2 \usepackage{charter}
     2 \usepackage{../style}
     3 \usepackage{hyperref}
       
     4 \usepackage{amssymb}
       
     5 
     3 
     6 \begin{document}
     4 \begin{document}
     7 
     5 
     8 \section*{Homework 4}
     6 \section*{Homework 4}
     9 
     7 
    27 \item What does it mean that the program \texttt{passwd} has the
    25 \item What does it mean that the program \texttt{passwd} has the
    28   \texttt{setuid} bit set? Why is this necessary?
    26   \texttt{setuid} bit set? Why is this necessary?
    29 
    27 
    30 \item With which permissions does the program \texttt{login}
    28 \item With which permissions does the program \texttt{login}
    31 normally have and why is this needed?
    29 normally have and why is this needed?
       
    30 
       
    31 \item The variable \texttt{PATH} is a shell variable in UNIX which
       
    32   lists all directories that should be automatically searched for a
       
    33   program. For example if \texttt{PATH} contains the directory
       
    34   \texttt{/usr/bin} and the program \texttt{ls} is stored there, then
       
    35   a user does not need to type \texttt{/usr/bin/ls} to run this file,
       
    36   but \texttt{ls} suffices. The question is why is it a bad idea in
       
    37   general, but in particular for root, to have \texttt{.} as the first
       
    38   entry in ones variable \texttt{PATH}?
    32 
    39 
    33 \item A Unix directory might look as follows:
    40 \item A Unix directory might look as follows:
    34 
    41 
    35 \begin{center}
    42 \begin{center}
    36 \begin{verbatim}
    43 \begin{verbatim}