Flex yylineno设置为1 [英] Flex yylineno set to 1

问题描述

我正在为tcpdump日志编写一个简单的解析器，您能告诉我为什么我无法获得正确的行号吗?

I'm writing a simple parser for tcpdump logs, could you please tell me why I can't get proper line number?

%{
char str[80];
%}
%option yylineno

...
%%

^{HOURS}:{MINUTES}:{MINUTES} if(input()=='.') { strcpy(str, yytext);  BEGIN(A); } else {printf("Wrong hour %d", yylineno); }
<A>({NDPS}|{DPS})\.({NDPS}|{DPS})\.({NDPS}|{DPS})|\.{NDPS} printf("Wrong IP!, %d", yylineno);
<A>[ ]{DPS}\.{DPS}\.{DPS}\.{DPS} strcat(str, " from "); strcat(str, yytext+1); BEGIN(B);
...

推荐答案

当我尝试此操作时，原来我必须有一个实际上与换行符匹配的规则才能更新yylineno.遵循以下规则，它可以工作，没有它，yylineno永远不会改变:

When I tried this, it turned out that I had to have a rule that actually matches newline for yylineno to be updated. With the following rule it worked, and without it yylineno never changed:

\n { }

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