A hack to implement vncconnect (http://www.tightvnc.com/doc/man/vncconnect.1.html)

Notes:
Wed Sep 7 10:34:59 EDT 2005 rsc
    This might be a generically useful utility.
    It has nothing to do with vnc.  

Wed Sep 7 10:55:15 EDT 2005 rsc
    I added a -a option to trampoline instead.  Use that.


Reference: /n/sources/patch/sorry/vncconnect
Date: Wed Sep  7 04:52:51 CES 2005
Reviewed-by: rsc

--- /sys/src/cmd/vncc.c	Thu Jan  1 00:00:00 1970
+++ /sys/src/cmd/vncc.c	Wed Sep  7 04:52:17 2005
@@ -0,0 +1,74 @@
+#include <u.h>
+#include <libc.h>
+
+int dflag;
+
+int dialerr(char*, char*);
+void xfer(int, int);
+
+void
+usage(void)
+{
+	fprint(2, "usage: %s server client\n", argv0);
+	exits("usage");
+}
+
+void
+main(int argc, char **argv)
+{
+	int sfd, cfd;
+
+	ARGBEGIN{
+	case 'd':
+		dflag ++;
+	}ARGEND;
+
+	if(argc != 2)
+		usage();
+
+	sfd = dialerr(argv[0], "server");
+	cfd = dialerr(argv[1], "client");
+
+	rfork(RFNOTEG);
+	switch(fork()){
+	case -1:
+		fprint(2, "%s: fork: %r\n", argv0);
+		exits("fork");
+	case 0:
+		xfer(sfd, cfd);
+		break;
+	default:
+		xfer(cfd, sfd);
+		break;
+	}
+	postnote(PNGROUP, getpid(), "die yankee pig dog");
+	exits(0);
+}
+
+int
+dialerr(char *dstr, char *msg)
+{
+	int fd;
+
+	fd = dial(dstr, 0, 0, 0);
+	if(fd < 0){
+		fprint(2, "%s: dialing %s: %r\n", argv0, dstr);
+		exits(smprint("dial %s", msg));
+	}
+	return fd;
+}
+
+/*
+ * borrowed from /sys/src/cmd/aux/trampoline.c
+ */
+void
+xfer(int from, int to)
+{
+
+	char buf[12*1024];
+	int n;
+
+	while((n = read(from, buf, sizeof buf)) > 0)
+		if(write(to, buf, n) < 0)
+			break;
+}