eof?()
public
Returns true if ios is at end of file that means there are no more data to read. The stream must be opened for reading or an IOError will be raised.
f = File.new("testfile") dummy = f.readlines f.eof #=> true
If ios is a stream such as pipe or socket, IO#eof? blocks until the other end sends some data or closes it.
r, w = IO.pipe Thread.new { sleep 1; w.close } r.eof? #=> true after 1 second blocking r, w = IO.pipe Thread.new { sleep 1; w.puts "a" } r.eof? #=> false after 1 second blocking r, w = IO.pipe r.eof? # blocks forever
Note that IO#eof? reads data to the input byte buffer. So IO#sysread may not behave as you intend with IO#eof?, unless you call IO#rewind first (which is not available for some streams).