von FleX erzeugt wird. Here is an example to create a simple terminal calculator program. Let’s create example.y: /* calculator source for bison */ %{ #include extern int yylex(void); extern int yyerror(char *s) { fprintf(stderr, ”error: ’%s’\n”, s); } Let’s create, example.l: /* calculator source for flex */ %{ #include ”example.tab.h” %} %% [0-9]+ { printf(”L: NUMBER = %s\n”, yytext);