.help bfchan Sep86 imfort.bfio .ih NAME bfchan -- return the kernel i/o channel of an open BFIO file .ih SYNOPSIS .nf integer function bfchan (fd) integer fd #I BFIO file descriptor of open file .fi .ih DESCRIPTION The \fIbfchan\fR procedure is used to get the i/o channel assigned to the file at open time by the binary file driver in the IRAF kernel. This may be used as input to the \fIzfiobf\fR binary file driver primitives if the lowest possible level of binary file i/o is desired (short of talking directly to the host system). The \fIzfiobf\fR procedures provide a direct (unbuffered), block oriented, asynchronous binary file i/o interface. .ih RETURN VALUE The i/o channel assigned to the file by the \fIzfiobf\fR binary file driver at open time is returned as the function value. .ih SEE ALSO The manual pages for the binary file driver. .endhelp