numeric func
A function to flush input or output on channel.
This element is applicable to external process channels opened for read-only or read/write, in which case all input will be flushed thereby discarding any data from the process waiting to be read.
It can also apply to text file channels opened for write, in which case any buffered output is flushed, thus ensuring that the file contents are up-to-date.
A value of 0 is returned when successful; 1 is returned on error.
The code of the function cannot be redefined.
channel.flush (<channel>)
The function may be called in one of two ways:
# Assume mychan is the channel identifier. channel.flush(mychan)
or
mychan.flush()