EOF encountered inside an action LEX program

Question

I have a lex program as follows. I encounter the error

EOF encountered inside an action LEX program

%{
#include<stdio.h>
#include<math.h>
#include "y.tab.h"
%}
%%
[ \t]+ ;
[0-9]+ {yylval = atoi(yytext);
 return INTEGER;}
[-+*/] {return *yytext;}
"(" {return *yytext;}
")" {return *yytext;}
\n {return *yytext;}
. {char msg[25];
 sprintf(msg,"%s <%s>","invalid character",yytext);
 yyerror(msg);}

Can someone help me out?

I see nothing wrong with that file. The error usually means you have a missing `}` but in this case, I copied the data from your question onto my machine and flex compiled it without complaint. Is it exactly the same as your file? — rici, Feb 09 '17 at 07:23

score 5 · Answer 1 · answered Feb 12 '17 at 14:09

This error often occurs if you have an EOF at the end of the text without terminating the last line with an end-of-line, but it can also be system dependent, making it hard to reproduce on other systems.

Ensure there is a blank line after the last line and the error is likely to go away.

EOF encountered inside an action LEX program

1 Answers1