#!/usr/local/bin/perl
#
# Please read all the comments down to the line that says "TOP".
# These comments are divided into three sections:
#
#     1. usage instructions
#     2. installation instructions
#     3. standard copyright
#
# Feel free to share this script with other instructors of programming
# classes, but please do not place the script in a publicly accessible
# place.  Comments, questions, and bug reports should be sent to
# moss-request@cs.berkeley.edu.
#
#

#
#  Section 1. Usage instructions
#
#  moss [-l language] [-d] [-b basefile1] ... [-b basefilen] [-m #] [-c "string"] file1 file2 file3 ...
#
# Submitted files can be in any subdirectory of the directory
# from which moss is run.  Please do not use absolute pathnames
# (e.g., /home/foo) or relative pathnames beginning with "..".
#
# The -l option specifies the source language of the tested programs.
# The current possibilities are: c (C), cc (C++), java, ml, lisp, scheme,
# pascal, ada, haskell, fortran, ascii, vhdl, html, perl, or matlab.  The default is c.
# Currently (as of 9/02) the last 6 of these are accessible using only the
# experimental server (see below).  After a period of testing the experimental
# server will be made the standard server.
#
# Example: Compare the lisp programs foo.lisp and bar.lisp:
#
#    moss -l lisp foo.lisp bar.lisp
#
#
# The -d option specifies that submissions are by directory, not by file.
# That is, files in a directory are taken to be part of the same program,
# and reported matches are organized accordingly by directory.
#
# Example: Compare the programs foo and bar, which consist of .c and .h
# files in the directories foo and bar respectively.
#
#    moss -d foo/*.c foo/*.h bar/*.c bar/*.h
#   
# Example: Each program consists of the *.c and *.h files in a directory under
# the directory "assignment1."
#
#    moss -d assignment1/*/*.h assignment1/*/*.c
#
#
# The -b option names a "base file".  Moss normally reports all code
# that matches in pairs of files.  When a base file is supplied,
# program code that also appears in the base file is not counted in matches.
# A typical base file will include, for example, the instructor-supplied 
# code for an assignment.  Multiple -b options are allowed.  You should 
# use a base file if it is convenient; base files improve results, but 
# are not usually necessary for obtaining useful information. 
#
# If the -d option is used, then the -b option names a directory in which
# the base file(s) are located.  In this case, the files to be treated
# as base files must appear in the file argument list.
#
# Examples:
#
#  Submit all of the C++ files in the current directory, using skeleton.cc
#  as the base file:
#
#    moss -l cc -b skeleton.cc *.cc
#
#  Submit all of the ML programs in directories asn1.96/* and asn1.97/*, where
#  asn1.97/instructor/*.ml and asn1.96/instructor/*.ml contain the base files.
#
#    moss -l ml -b asn1.97/instructor -b asn1.96/instructor -d asn1.97/*/*.ml asn1.96/*/*.ml 
#
# The -m option sets the maximum number of times a given passage may appear
# before it is ignored.  A passage of code that appears in many programs
# is probably legitimate sharing and not the result of plagiarism.  With -m N,
# any passage appearing in more than N programs is treated as if it appeared in 
# a base file (i.e., it is never reported).  Option -m can be used to control
# moss' sensitivity.  With -m 2, moss reports only passages that appear
# in exactly two programs.  If one expects many very similar solutions
# (e.g., the short first assignments typical of introductory programming
# courses) then using -m 3 or -m 4 is a good way to eliminate all but
# truly unusual matches between programs while still being able to detect
# 3-way or 4-way plagiarism.  With -m 1000000 (or any very 
# large number), moss reports all matches, no matter how often they appear.  
# The -m setting is most useful for large assignments where one also a base file 
# expected to hold all legitimately shared code.  The default for -m is 10.
#
# Examples:
#
#   moss -l pascal -m 2 *.pascal 
#   moss -l cc -m 1000000 -b mycode.cc asn1/*.cc
#
# 
# The -c option supplies a comment string that is attached to the generated
# report.  This option facilitates matching queries submitted with replies
# received, especially when several queries are submitted at once.
#
# Example:
#
#   moss -l scheme -c "Scheme programs" *.sch
#
 
# The -x option sends queries to the current experimental version of the server.
# The experimental server has the most recent Moss features and is also usually
# less stable (read: may have more bugs).
#
# Example:
#
#   moss -x -l ml *.ml
#


#
# Section 2.  Installation instructions.
#     
# On many Unix systems this script should work as is.  If you have problems
# check the following:
#
# - You may need to change the very first line of this script
#   if perl is not in /usr/bin on your system.  Just replace /usr/bin
#   with the pathname of the directory where perl resides.
#
# - The system programs uuencode and mail are required.
#   One of zip or tar is also required.
#   These should accessible through $PATH when this script is run.
#   Alternatively, the full pathnames can be put here.
#
#   (If you don't have zip or tar, zip binaries for many machines 
#   as well as source are available from:
#       http://mcftp.mclink.it/simtel.net/infozip/Zip.html
#   )
#  
$zip = "zip"; 
$tar = "tar";
$uuencode = "uuencode";
$mail = "mail";

#
# - The following directories and files must be readable and writable.
#   On Unix systems there should be no need to change these settings,
#   but there is no harm in changing them, either.
#
$tempdir = "/tmp";
$zipfile = "$tempdir/mossfile";
$mailmessage = "$tempdir/mossmail";

#
#  3. Standard Copyright
#
#Copyright (c) 1997 The Regents of the University of California.
#All rights reserved.
#
#Permission to use, copy, modify, and distribute this software for any
#purpose, without fee, and without written agreement is hereby granted,
#provided that the above copyright notice and the following two
#paragraphs appear in all copies of this software.
#
#IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
#DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
#OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
#CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
#THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
#INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
#AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
#ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
#PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
#
#
# STOP.  It should not be necessary to change anything below this line
# to use the script.
#
$server = 'moss@cs.berkeley.edu';
$noreq = "Request not sent.";
$usage = "usage: moss [-l language] [-d] [-b basefile1] ... [-b basefilen] [-m #] [-c \"string\"] file1 file2 file3 ...";

#
# The userid is used to authenticate your queries to the server; don't change it!
#
$userid=306435351;

#
# Process the command line options.  This is done in a non-standard
# way to allow multiple -b's.
#
$opt_l = "c";   # default language is c
$opt_d = 0;
$bindex = 0;
$opt_c = "";

while (@ARGV && ($_ = $ARGV[0]) =~ /^-(.)(.*)/) {
    ($first,$rest) = ($1,$2);	
    die "Unrecognized option -$first.  $usage\n" unless (($first eq "d") || ($first eq "l") || ($first eq "b") || ($first eq "m") || ($first eq "c") || ($first eq "x"));
    
    shift(@ARGV);
    if ($first eq "d") {
	$opt_d = 1;
    }
    if ($first eq "b") {
	if($rest eq '') {
	    die "No argument for option -b.\n" unless @ARGV;
	    $rest = shift(@ARGV);
	}
	$opt_b[$bindex++] = $rest;
    }
    if ($first eq "l") {
	if($rest eq '') {
	    die "No argument for option -l.\n" unless @ARGV;
	    $rest = shift(@ARGV);
	}
	$opt_l = $rest;
    }
    if ($first eq "m") {
	if($rest eq '') {
	    die "No argument for option -m.\n" unless @ARGV;
	    $rest = shift(@ARGV);
	}
	$opt_m = $rest;
    }
    if ($first eq "c") {
	if($rest eq '') {
	    die "No argument for option -c.\n" unless @ARGV;
	    $rest = shift(@ARGV);
	}
	$opt_c = $rest;
    }
# 
# The -x flag signals the server to use the current experimental (and
# possibly unstable) version of moss. 
#
    if ($first eq "x") {
	$opt_x = 1;
    }
}

#
# Check a bunch of things first to ensure that the
# script will be able to run to completion.
#

#
# make sure we have a supported language
die "Unrecognized language $opt_l (should be one of c, cc, java, ml, pascal, ada, lisp, scheme, haskell, fortran, ascii, vhdl, html, perl, matlab)." unless $opt_l eq "c" || $opt_l eq "cc" || $opt_l eq "java" || $opt_l eq "ml" || $opt_l eq "pascal" || $opt_l eq "lisp" || $opt_l eq "scheme" || $opt_l eq "ada" || $opt_l eq "haskell" || $opt_l eq "fortran" || $opt_l eq "ascii" || $opt_l eq "vhdl" || $opt_l eq "html" || $opt_l eq "perl"  || $opt_l eq "matlab" ;

#
# Make sure there is a directory for temporary files that we can read and write.
#
die ("The $tempdir directory does not exist; I need it to write temprorary files\n.") unless -e $tempdir;
die ("The $tempdir directory is either unreadable or writablel I need it for temporary files.\n") unless -r $tempdir && -w $tempdir;

#
# Make sure all the argument files exist and are readable.
#
print "Checking files . . . \n";
$i = 0;
while($i < $bindex)
{
    die "Base file $opt_b does not exist. $noreq\n" unless -e "$opt_b[$i]";
    die "Base file $opt_b is not readable. $noreq\n" unless -r "$opt_b[$i]";
    if ($opt_d == 0)
    { die "Base file $opt_b is not a text file. $noreq\n" unless -T "$opt_b[$i]";}
    else
    { die "With -d, base file $opt_b[$i] should name a directory. $noreq\n" unless -d "$opt_b[$i]"; }
    $i++;
}
foreach $file (@ARGV)
{
    die "File $file does not exist. $noreq\n" unless -e "$file";
    die "File $file is not readable. $noreq\n" unless -r "$file";
    die "File $file is not a text file. $noreq\n" unless -T "$file";
}

if ("@ARGV" eq '') {
    die "No files submitted.\n $usage";
}
print "OK\n";

#
# These files shouldn't be there, but remove them just in case.
#
unlink "$zipfile.zip";
unlink "$zipfile.tar";
unlink $mailmessage;

#
# open the mail message
#
open(MAIL,">$mailmessage") || die "Could not open file $mailmessage for writing.";

#
# Now the real processing begins.
#

#
# calculate file arguments for zip;
# this may or may not include a base file.
#
if ($opt_d == 1)
{ $fileargs = "@ARGV";}
else
{$fileargs = "@opt_b @ARGV"};

print MAIL "query\n";
#
# put user number in request; this is required!
#
print MAIL "user $userid\n";

#
# put source language in request
#
print MAIL "-l $opt_l\n";

#
# if there are basefiles, add them to the request, too.
#
$i = 0;
while($i < $bindex) {
    print MAIL "-b $opt_b[$i++]\n"; 
}

#
# include the directory option if appropriate
#
if ($opt_d == 1) { print MAIL "-d\n"; }

#
# use experimental version of moss if requested
#
if ($opt_x == 1) { print MAIL "-x\n"; }

#
# and the -m option . . .
#
if ($opt_m ne '') { print MAIL "-m $opt_m\n"; }

#
# and any comment
#
if ($opt_c ne '') { print MAIL "-c $opt_c\n"; }

#
# zip and uuencode the source files
#
close(MAIL);
system("$zip $zipfile $fileargs");
system("$uuencode $zipfile.zip mossfile.zip >> $mailmessage") if -e "$zipfile.zip";

if (!(-e "$zipfile.zip"))
{
    print "No zip available; trying tar.\n";
    system("$tar -cvf $zipfile.tar $fileargs");
    system("$uuencode $zipfile.tar mossfile.tar >> $mailmessage") if -e "$zipfile.tar";
}
die "Neither zip nor tar is available. $noreq" unless ((-e "$zipfile.zip") || (-e "$zipfile.tar"));

#
# send request
#
system("$mail $server < $mailmessage");
print "Request sent; results will be sent to you by email.\n";

#
# cleanup
#
unlink "$zipfile.zip";
unlink "$zipfile.tar";
unlink $mailmessage;