ref: de1e5e3e01aaa92979d41a2cf8d33346e5f8d5ce dir: /sys/src/ape/lib/bsd/setlinebuf.c/
#include <stdio.h> void setlinebuf(FILE *f) { static char buf[BUFSIZ]; setvbuf (f, buf, _IOLBF, BUFSIZ); }