Reads octets from the channel and puts them into the string. The * first int argument is the position of the substring, and the second * int argument is the length of the substring where the data are * stored. The method returns the number of octets actually read and * stored. * * When the end of the channel is reached and there is no further octet * to read, the exception End_of_file will be raised. This has * been changed in ocamlnet-0.97! In previous releases the number 0 * was returned at the end of the channel. * * When the channel is non-blocking, and there are currently no bytes * to read, the number 0 will be returned. This has * been changed in ocamlnet-0.97! In previous releases this behaviour * was undefined. * * When the channel is closed, the exception Closed_channel will be * raised if an ocamlnet implementation is used. For implementations * of other libraries there is no standard for this case.

Closes the channel for input. * * When the channel is already closed, this is a no-op. * * Error policy: Exceptions are only raised in cases of serious * corruption, e.g. if the underlying descriptor is invalid.