ref: 740b766e5a9b0101225c23a5f9920d7d8b8fc67d dir: /sys/src/ape/lib/bsd/setlinebuf.c/
#include <stdio.h> void setlinebuf(FILE *f) { static char buf[BUFSIZ]; setvbuf (f, buf, _IOLBF, BUFSIZ); }