ref: 43e436fe16dc8e3d18e15c03be8ff32124ff0f94 dir: /examples/username.peg/
%{ #include <unistd.h> %} start = "username" { printf("%s", getlogin()); } | < . > { putchar(yytext[0]); } %% int main() { while (yyparse()); return 0; }