Extended maintenance of Ruby versions 1.8.7 and 1.9.2 ended on July 31, 2014. Read more

In Files

  • io.c



Raised when an IO operation fails.

File.open("/etc/hosts") {|f| f << "example"}
  #=> IOError: not opened for writing

File.open("/etc/hosts") {|f| f.close; f.read }
  #=> IOError: closed stream

Note that some IO failures raise +SystemCallError+s and these are not subclasses of IOError:

  #=> Errno::ENOENT: No such file or directory - does/not/exist