I am storing the arguments passed to main in yacc in a file. Now I want the lex to read its input from this file rather than the terminal. I know I can point yyin to a file
like yyin = fopen("fn","r"); but this works only when main is in lex. When I use this yyin declaration in main in yacc, it shows an error so please suggest something to overcome this problem.
You probably just need to declare
extern FILE * yyin;
If that doesn't solve the problem, please give the error message you got.
来源：https://stackoverflow.com/questions/1796520/in-lex-how-to-make-yyin-point-to-a-file-with-the-main-function-in-yacc