-mail: mail.c /usr/include/sys/param.h /usr/include/sys/types.h
-mail: /usr/include/signal.h /usr/include/machine/trap.h
-mail: /usr/include/machine/machparam.h /usr/include/machine/endian.h
-mail: /usr/include/sys/stat.h /usr/include/sys/file.h /usr/include/ctype.h
-mail: /usr/include/stdio.h /usr/include/pwd.h /usr/include/utmp.h
-mail: /usr/include/signal.h /usr/include/setjmp.h /usr/include/sys/socket.h
-mail: /usr/include/netinet/in.h /usr/include/netdb.h