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\section*{Coursework 7CCSMSEN}+
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+
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This coursework is worth 4\% and is due on 19 October at+
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16:00. You are asked to implement a regular expression matcher+
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and submit a document containing the answers for the questions+
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below. You can do the implementation in any programming+
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language you like, but you need to submit the source code with+
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which you answered the questions, otherwise a mark of 0\% will+
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be awarded. You can submit your answers in a txt-file or pdf.+
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Code send as code.+
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+
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+
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+
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\subsubsection*{Disclaimer}+
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+
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It should be understood that the work you submit represents+
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your own effort. You have not copied from anyone else. An+
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exception is the Scala code I showed during the lectures or+
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uploaded to KEATS, which you can freely use.\bigskip+
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+
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+
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\subsection*{Task}+
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+
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A Unix directory might look as follows:+
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+
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\begin{center}+
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\begin{verbatim}+
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$ ls -ld . * */*+
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drwxr-xr-x 1 ping staff  32768 Apr  2 2010 .+
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-rw----r-- 1 ping students  31359 Jul 24 2011 manual.txt+
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-r--rw--w- 1 bob students   4359 Jul 24 2011 report.txt+
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-rwsr--r-x 1 bob students 141359 Jun  1 2013 microedit+
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dr--r-xr-x 1 bob staff  32768 Jul 23 2011 src+
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-rw-r--r-- 1 bob staff  81359 Feb 28 2012 src/code.c+
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-r--rw---- 1 emma students    959 Jan 23 2012 src/code.h+
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\end{verbatim}+
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\end{center}+
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+
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with group memberships assigned as follows:+
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\begin{center}+
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\begin{tabular}{ll}+
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Members of group staff: & ping, bob, emma\\ +
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Members of group students: & emma\\+
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\end{tabular}+
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\end{center}+
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+
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The file microedit is a text editor, which allows its users to open, edit and +
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save files. Note carefully that microedit has set its setuid flag. +
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Fill in the access control matrix below that shows for each of the above five files, +
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whether ping, bob, or emma are able to obtain the right to read (R) or replace (W) its +
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contents using the editor microedit.\bigskip+
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+
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\begin{center}+
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\begin{tabular}{r|c|c|c|c|c}+
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        & manual.txt & report.txt & microedit & src/code.c & src/code.h \\\hline+
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ping & & & & &\\\hline+
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bob & & & & &\\\hline+
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emma   & & & & &\\+
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\end{tabular}+
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\end{center}+
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+
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+
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\end{document}+
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