setNONBLOCK

Command: setNONBLOCK


Description
"setNONBLOCK" sets or erases the O_NONBLOCK flag on
an input stream. The O_NONBLOCK flag determines if
a read attempt will block when no data is currently
available from the stream. By default a newly
created stream has the O_NONBLOCK-Flag erased
meaning that blocking I/O is selected. By erasing
O_NONBLOCK a subsequent read attempt on the stream
will yield EOF if no data is availabe.

Alternatives: Function setNONBLOCK_is_b (undocumented)
-> behaviour and synopsis are the same.

Parameters
In : ifstream: The stream to change the flag on.
Out: -

Author
R Kupper

Bugs
-

Synopsis
ifstream {true|false} setNONBLOCK -> ifstream

Examples
cin false setNONBLOCK
myfifo true setNONBLOCK % set non-blocking I/O for my fifo.

File
sli/processes.h
Diagnostics
If a system-error occurs a code is stored in "sys_errno"
(contained in errordict) to identify the error and "sys_errname" is
set to the error message. Then a "SystemError" is raised.
The following system errors may be issued according to the
POSIX standard (errors in parantheses are not
expected to occur in this routines' context):

(EACCES) Search permission is denied for a
directory in a files path prefix.
(EAGAIN) The ON_NONBLOCK flag is set for a file
descriptor and the process would be
delayed in the I/O operation.
EBADF Invalid file descriptor. (With the current
implementation this indicates trouble
getting a fildescriptor from a stream. If
it occurs ask the author for a proper
soultion!)
(EDEADLK) An fcntl with function F_SETLKW would
cause a deadlock.
EINTR Function was interrupted by a signal.
(EINVAL) Invalid argument.
(EMFILE Too many file descriptors are in use by
this process.
(ENOLCK) No locks available.

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