start of a lexer for dns zone files

2011-07-11 11:44:35 +02:00 · 2011-07-11 11:44:35 +02:00 · 82ff70262b
parent 3f9b67632a
commit 82ff70262b
1 changed files with 60 additions and 0 deletions
--- a/dns.l
+++ b/dns.l
@ -0,0 +1,60 @@
+    package main
+
+    import "fmt"
+
+CHAR    [A-Za-z0-9/+=a.{}]
+WS      [ \t]
+
+%x qclass qtype rdata
+%%
+
+^{CHAR}+            { 
+                        YOUT("qname")
+                        BEGIN(qclass)
+                    }
+WS                      YOUT(" ")
+<qclass>WS              YOUT(" ")
+<qtype>WS               YOUT(" ")
+<rdata>WS               YOUT(" ")
+;.*\n               {
+                        YOUT("comment\n")
+                        BEGIN(INITIAL)
+                    }
+<qclass>;.*\n       {
+                        YOUT("comment\n")
+                        BEGIN(INITIAL)
+                    }
+<qtype>;.*\n        {
+                        YOUT("comment\n")
+                        BEGIN(INITIAL)
+                    }
+<rdata>;.*\n        {
+                        YOUT("comment\n")
+                        BEGIN(INITIAL)
+                    }
+
+<qclass>{CHAR}+     {
+                        YOUT("qclass/ttl")
+                        BEGIN(qtype)
+                    }
+<qtype>{CHAR}+      {
+                        YOUT("qtype")
+                        BEGIN(rdata)
+                    }
+<rdata>{CHAR}+      {
+                        YOUT("rdata")
+                    }
+<rdata>\n           {
+                        YOUT("END\n\n")
+                        BEGIN(INITIAL)
+                    }
+%%
+
+
+func YOUT(s string) {
+    fmt.Printf("%s", s)
+}
+
+func main() {
+    yylex()
+}