ref: fd8a2d81c3ddf6584d2b47f1b8efe30b66beb7b5 dir: /sys/src/ape/lib/ap/plan9/fsync.c/
#include <sys/types.h> #include <unistd.h> #include <errno.h> int fsync(int) { errno = EINVAL; return -1; }