stdio/setbuffer.c

#include <stdio.h>

void setbuffer(FILE *fp, char *buf, size_t size) {
	setvbuf(fp, buf, buf ? _IOFBF : _IONBF, size);
}

void setbuf(FILE *fp, char *buf) {
	setvbuf(fp, buf, buf ? _IOFBF : _IONBF, BUFSIZ);
}