I was trying to learn lex/yacc decided to use Plan9 (9vx) for writing
example programs. I wrote the following

stop print("Stop!! recieved\n");
start print("Start -> recieved\n");


I lex'ed it
-> lex -9 start.l
-> 8c lex.yy.c
-> 8l lex.yy.8
-> ./8.out
output: inappropriate use of fd
sd: /bin/sd file does not exists

(with small modifications i.e use of and using printf, I am
able to compiler and run this). could someone help whats happening in
this case ..