Actually it is probably the other way. The cu (call unix) device was primarily for UUCP communications. The tty port is mostly used these days. Both do the exact same thing, it is the defaults when they are opened that are different. You should immediately set the port for whatever handshaking and control you need after opening which tends to negate the defaults and give you the desired environment.
See: http://lists.apple.com/archives/darwin-dev/2009/Nov/msg00099.html for some interesting discussion. - Jack > On Jun 8, 2015, at 5:54 PM, Carl Hoefs <[email protected]> wrote: > > >> On Jun 8, 2015, at 5:25 PM, Roland King <[email protected] >> <mailto:[email protected]>> wrote: >> >> The difference between the tty device and the cu device is that ttys were >> traditionally used to connect a terminal to, so opening a tty should block >> until the device on the other end raises DTR (ie you turn it on). getty >> opens tty devices and blocks in this way. The cu devices were designed for >> callups where you needed to connect to say a modem first, then dial, and >> only when the connection was established does DTR go high; so open doesn’t >> block. >> > Okay, that sounds like in general /dev/cu would almost always be called for > (unless you’re doing actual terminal or modem work!) The way USB/serial > devices seem to work on OS X is that they don’t even show up with a mount > point unless they’re ready to communicate (perhaps at some level simulating > DTR high?). In practice it hasn’t made any difference which I’ve used, cu or > tty, but this info is good to know regardless. > -Carl > > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Usb mailing list ([email protected]) > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/usb/jackbrindle%40me.com > > This email sent to [email protected]
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