/* This is a lex program to identify and count identifiers, keywords, numbers and operators in a c program */
%{
	int numcount=0,idcount=0, keycount=0, opcount=0;
%}
id [a-zA-Z][A-Za-z0-9]*
num [0-9]+
keywords "auto"|"break"|"case"|"char"|"const"|"continue"|"default"|"do"|"double"|"else"|"enum"|"extern"|"float"|"for"|"goto"|"if"|"int"|"long"|"register"|"return"|"short"|"signed"|"sizeof"|"static"|"struct"|"switch"|"typedef"|"union"|"unsigned"|"void"|"volatile"|"while"
test "eureka"

preprocessor [#][a-z A-Z0-9\.<>]*
operators [+\-=/*]


%%

 /*"quit" {
	printf("There are %d numbers.\n",numcount);
	printf("There are %d identifiers.\n",idcount);
	yyterminate();
	}*/

{preprocessor}  {
		printf("Skipping preprocessor directives %s\n",yytext);
}

{keywords}	{
		printf("%s is a keyword.\n",yytext);
		keycount++;
}

{test} 		{
		printf("This is a test.\n");
}

{id} 		{
		printf("%s is an Identifier\n",yytext);
		idcount++;
}


{num} 		{
		printf("%s is a Number\n",yytext);
		numcount++;
}

{operators} 	{
		printf("%s is an operator.\n",yytext);
		opcount++;
 }

.	{;}

%%

int
main(int argc, char **argv){
	if(argc==2){
		yyin=fopen(argv[1],"r");
	}
	yylex();
	printf("There are %d numbers.\n",numcount);
	printf("There are %d identifiers.\n",idcount);
	printf("There are %d keywords.\n",keycount);
	printf("There are %d operators.\n",opcount);
	return;
}