Thanks to John Cummings.

src/cmd/upas/scanmail/spam.h

@@ -0,0 +1,62 @@
+
+enum{
+	Dump		= 0,		/* Actions must be in order of descending importance */
+	HoldHeader,
+	Hold,
+	SaveLine,
+	Lineoff,			/* Lineoff must be the last action code */
+	Nactions,
+
+	Nhash		= 128,
+
+	regexp		= 1,		/* types: literal string or regular expression */
+	string		= 2,
+
+	MaxHtml		= 256,
+	Hdrsize		= 4096,
+	Bodysize	= 8192,
+	Maxread		= 64*1024,
+};
+
+typedef struct spat 	Spat;
+typedef struct pattern	Pattern;
+typedef	struct patterns	Patterns;
+struct	spat
+{
+	char*	string;
+	int	len;
+	int	c1;
+	Spat*	next;
+	Spat*	alt;
+};
+
+struct	pattern{
+	struct	pattern *next;
+	int	action;
+	int	type;
+	Spat*	alt;
+	union{
+		Reprog*	pat;
+		Spat*	spat[Nhash];
+	};
+};
+
+struct	patterns {
+	char	*action;
+	Pattern	*strings;
+	Pattern	*regexps;
+};
+
+extern	int	debug;
+extern	Patterns patterns[];
+extern	char	header[];
+extern	char	cmd[];
+
+extern	void	conv64(char*, char*, char*, int);
+extern	int	convert(char*, char*, char*, int, int);
+extern	void*	Malloc(long n);
+extern	int	matchpat(Pattern*, char*, Resub*);
+extern	char*	readmsg(Biobuf*, int*, int*);
+extern	void	parsepats(Biobuf*);
+extern	void*	Realloc(void*, ulong);
+extern	void	xprint(int, char*, Resub*);