From: fjh@cs.mu.OZ.AU (Fergus Henderson) Subject: Re: Opening COM2 4 Apr 1997 04:48:16 -0800 Approved: cygnus.gnu-win32@cygnus.com Distribution: cygnus Message-ID: <199704040408.OAA02825.cygnus.gnu-win32@mundook.cs.mu.OZ.AU> Content-Type: text Original-To: rwilson@cfawilson.harvard.edu (Bob Wilson) Original-Cc: gnu-win32@cygnus.com (gnu-win32) In-Reply-To: <199704032002.PAA00930@cfawilson.harvard.edu> from "Bob Wilson" at Apr 3, 97 03:02:58 pm X-Mailer: ELM [version 2.4 PL24] Original-Sender: owner-gnu-win32@cygnus.com Bob Wilson, you wrote: > > I have a program which ran correctly when compiled on a gnu-win32 > package from about a year ago, but is failing when compiled with 17.1 > beta. The machine is running NT 3.51 and COM2 is connected to a > microprocessor with only td, rd and ground connected. The open: > > if ((comfd = open("com2", O_RDWR | O_TEXT)) <= 0) { > fprintf(stderr, "Cmd: Unable to open terminal\n"); > exit(1); > } > > hangs. It doesn't help to tie the modem control lines high, but if I > generate a few characters on the rd line, the open completes. In no > case is there an error return. My guess is that this is due to the symbolic link handling. When you open a file, cygwin will read the first few bytes of the file to see if it has the special marker that is used to indicate a symbolic link; if so, then cygwin will open the file that the link points to. Obviously this won't work correctly in the case of device files such as `com2'... -- Fergus Henderson | "I have always known that the pursuit WWW: | of excellence is a lethal habit" PGP: finger fjh@128.250.37.3 | -- the last words of T. S. Garp. - For help on using this list, send a message to "gnu-win32-request@cygnus.com" with one line of text: "help".