IdGxDL - Online Prolog Interpreter & Debugging Tool

%{
int COMMENT=0;
%}

identifier [a-zA-Z_][a-zA-Z0-9_]*
keyword int|float|char|double|while|for|struct|typedef|do|if|break|continue|void|switch|return|else|goto

%%
#.*                     {printf("\n%s is a preprocessor directive",yytext);}
{keyword}               {printf("\n%s is a keyword",yytext);}
"/*"                    {COMMENT=1; printf("\n\t%s is a COMMENT",yytext);}
"*/"                    {COMMENT=0; printf("\n\t%s is a COMMENT",yytext);}
{identifier}\(           {if(!COMMENT) printf("\nFUNCTION \n\t%s",yytext);}
\{                      {if(!COMMENT) printf("\nBLOCK BEGINS");}
\}                      {if(!COMMENT) printf("BLOCK ENDS ");}
{identifier}(\[[0-9]*\])? {if(!COMMENT) printf("\n%s IDENTIFIER",yytext);}
\".*\"                  {if(!COMMENT) printf("\n\t%s is a STRING",yytext);}
[0-9]+                  {if(!COMMENT) printf("\n%s is a NUMBER",yytext);}
=                       {if(!COMMENT) printf("\n\t%s is an ASSIGNMENT OPERATOR",yytext);}
\<=|\>=|==|<|>          {if(!COMMENT) printf("\n\t%s is a RELATIONAL OPERATOR",yytext);}
\(                       {ECHO;}
\)                       {ECHO; printf("\n");}
.                        {if(!COMMENT) ECHO;}
%%

int main() {
    FILE *file=fopen("var.c","r");
    if(!file){printf("could not open file"); exit(0);}
    yyin=file;
    yylex();
    return 0;
}
int yywrap(){return 1;}