ref: fda3acee5812fcae68ed2a50c2cbe15f7f354dfd dir: /sys/src/ape/lib/bsd/setlinebuf.c/
#include <stdio.h> void setlinebuf(FILE *f) { static char buf[BUFSIZ]; setvbuf (f, buf, _IOLBF, BUFSIZ); }