ref: 1d5a2aa48778960fc9b5ab0b39f83a5322c3f754
dir: /sys/src/libstdio/setbuf.c/
/* * pANS stdio -- setbuf */ #include "iolib.h" void setbuf(FILE *f, char *buf){ if(f->state==OPEN){ if(buf) f->bufl=BUFSIZ; else{ buf=f->unbuf; f->bufl=0; } f->rp=f->wp=f->lp=f->buf=buf; f->state=RDWR; } /* else error, but there's no way to report it */ }