ref: c325c491f61696e81ab0ee9e6aea840c3636ed3d
dir: /sys/src/libbio/btestprint.c/
#include <u.h>
#include <libc.h>
#include <bio.h>
void
main(int argc, char **argv)
{
Biobuf b;
char *s;
int n;
n = atoi(argv[1]);
s = malloc(n+1);
memset(s, 'a', n);
s[n] = '\0';
Binit(&b, 1, OWRITE);
Bprint(&b, "%s\n", s);
Bflush(&b);
}