Extended maintenance of Ruby 1.9.3 ended on February 23, 2015. Read more
Returns number of bytes that can be read without blocking. Returns zero if no information available.
static VALUE io_nread(VALUE io) { rb_io_t *fptr; int len; ioctl_arg n; GetOpenFile(io, fptr); rb_io_check_readable(fptr); len = rb_io_read_pending(fptr); if (len > 0) return len; if (!FIONREAD_POSSIBLE_P(fptr->fd)) return INT2FIX(0); if (ioctl(fptr->fd, FIONREAD, &n)) return INT2FIX(0); if (n > 0) return ioctl_arg2num(n); return INT2FIX(0); }
Returns true if input available without blocking, or false. Returns nil if no information available.
static VALUE io_ready_p(VALUE io) { rb_io_t *fptr; ioctl_arg n; GetOpenFile(io, fptr); rb_io_check_readable(fptr); if (rb_io_read_pending(fptr)) return Qtrue; if (!FIONREAD_POSSIBLE_P(fptr->fd)) return Qnil; if (ioctl(fptr->fd, FIONREAD, &n)) return Qnil; if (n > 0) return Qtrue; return Qfalse; }
Waits until input is available or times out and returns self or nil when EOF is reached.
static VALUE io_wait(int argc, VALUE *argv, VALUE io) { rb_io_t *fptr; int i; ioctl_arg n; VALUE timeout; struct timeval timerec; struct timeval *tv; GetOpenFile(io, fptr); rb_io_check_readable(fptr); rb_scan_args(argc, argv, "01", &timeout); if (NIL_P(timeout)) { tv = NULL; } else { timerec = rb_time_interval(timeout); tv = &timerec; } if (rb_io_read_pending(fptr)) return Qtrue; if (!FIONREAD_POSSIBLE_P(fptr->fd)) return Qfalse; i = rb_wait_for_single_fd(fptr->fd, RB_WAITFD_IN, tv); if (i < 0) rb_sys_fail(0); rb_io_check_closed(fptr); if (ioctl(fptr->fd, FIONREAD, &n)) rb_sys_fail(0); if (n > 0) return io; return Qnil; }
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