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<H2><A NAME="SECTION00073000000000000000"></A><A NAME="engine"></A>
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Scan engine
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New versions of Clam AntiVirus use a mutation of the Aho-Corasick
pattern matching algorithm. The algorithm is based a finite state pattern
matching automaton [<A
HREF="node85.html#clr">1</A>] and it's a generalization of the famous
Knuth-Morris-Pratt algorithm. Please take a look at the <code>matcher.h</code>
for data type definitions. The automaton is represented by a trie. It
is a rooted tree with some specific properties [<A
HREF="node85.html#acwww">2</A>]. Every node
of the trie represents some state of the automaton. In our implementation,
the node is defined as follows:
<PRE>
struct cl_node {
short int islast;
struct cli_patt *list;
int maxpatlen;
struct node *next[NUM_CHILDS], *trans[NUM_CHILDS], *fail;
};
</PRE>
[To be continued...]
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<ADDRESS>
Tomasz Kojm
2004-06-14
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