dtrace keystrokes

keystrokes.d

#!/usr/sbin/dtrace -s

syscall::read:entry
/execname == "sh"   || execname == "ksh"  || execname == "csh"  ||
 execname == "tcsh" || execname == "zsh"  || execname == "bash"/
{
        self->start = timestamp;
        self->buf = arg1;
        self->len = arg2;
}

syscall::read:return
/self->start && self->len == 1/
{
        this->elapsed = timestamp - self->start;
        @edist = quantize(this->elapsed / 1000000);

        this->text = (char *) copyin(self->buf, self->len);
        @ldist[stringof(this->text)] = quantize(this->elapsed / 1000000);

        printf("%d ms %s letter", this->elapsed / 1000000, stringof(this->text));

        self->start = 0;
        self->buf = NULL;
        self->len = 0;
}