# Reads in lines of text until "quit" is read.
# Then prints duplicates, or prints "No duplicates seen."

my %lines; # holds lines of text encountered along with a count
           # of how many times it has been seen
my @dups;

while ( $_ = <> and $_ ne "quit\n" )
{
    $lines{$_}++; # increment value. if it dosn't exist yet, initializ
+es to 1
    if ( $lines{$_} == 2 ) # been seen before so add to dupes list
    {
        push @dups, $_;
    }
}

if ( @dups )
{
    print "Here are your duplicate lines:\n\n";
    foreach ( @dupes )
    {
        print;
    }
}
else
{
    print "No duplicates seen.\n";
}

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In reply to Control Statements #1 by vroom
in thread Control Statement Exercises by vroom

Title:
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