1 files changed, 108 insertions, 0 deletions
diff --git a/erts/etc/vxworks/erl_io.c b/erts/etc/vxworks/erl_io.c
new file mode 100644
index 0000000000..0032b77079
--- /dev/null
+++ b/erts/etc/vxworks/erl_io.c
@@ -0,0 +1,108 @@
+/*
+ * %CopyrightBegin%
+ * 
+ * Copyright Ericsson AB 1997-2009. All Rights Reserved.
+ * 
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ * 
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ * 
+ * %CopyrightEnd%
+ */
+/* Some stuff to let the Erlang and VxWorks shells coexist peacefully.
+   Basically, run Erlang as a spawned task with input redirected to
+   the slave side of a pseudo-tty, and connect explicitly to the master
+   side of the pseudo-tty to send input to Erlang when desired. */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+#include <stdio.h>
+#include <ioLib.h>
+#include <taskLib.h>
+#include <ptyDrv.h>
+
+extern int spTaskPriority, spTaskOptions;
+
+#define TBUFSIZ 512
+
+#define DEFAULT_STACK_SIZE    100000
+
+static int slavefd = -1, masterfd = -1;
+static run_erl();
+
+/* Frontend to the Erlang startup function - callable from VxWorks shell
+   or script. 'arg' is actually a string passed to the real startup. */
+start_erl(arg)
+int arg;
+{
+  int stacksize;
+  char *stackenv;
+
+    /* create and open the pty - we want the master side to be open
+       all the time, since closing it probably generates EOF on the
+       slave side */
+    (void)ptyDevCreate("/pty/erlang.", TBUFSIZ, TBUFSIZ);
+    if (slavefd != -1)
+	(void)close(slavefd);
+    slavefd = open("/pty/erlang.S", O_RDONLY, 0);
+    if (masterfd != -1)
+	(void)close(masterfd);
+    masterfd = open("/pty/erlang.M", O_WRONLY, 0);
+
+    /* flush any old leftover garbage */
+    (void) ioctl(masterfd, FIOFLUSH, 0);
+    if ((stackenv = getenv("ERLSTACKSIZE")) == NULL)
+      stacksize = DEFAULT_STACK_SIZE;
+    else
+      stacksize = atoi(stackenv);
+    /* spawn Erlang, via stub below */
+    return(taskSpawn("erlang", spTaskPriority, spTaskOptions, stacksize,
+		     run_erl, arg, 0,0,0,0,0,0,0,0,0));
+}
+
+/* Little stub that runs in the spawned task - we need this to redirect
+   stdin reliably (redirections aren't "inherited" in VxWorks) */
+static
+run_erl(arg)
+int arg;
+{
+    ioTaskStdSet(0, 0, slavefd); /* redirect stdin to slave side of pty */
+
+    /* We don't want to redirect stdout/err since no one will be reading
+       from the master side (to_erl - and the open()s above - could be
+       made bidirectional, but still the master side would only be read
+       when to_erl was running), and output can eventually fill the pty
+       buffer and cause the Erlang system to block. Not redirecting
+       stdout/err will have the effect that output from Erlang, e.g. the
+       shell prompt, will appear on console/rlogin/whatever even when
+       to_erl isn't running, which may be confusing - can't win 'em all... */
+
+    erl_exec(arg, 0,0,0,0,0,0,0,0);	/* call the real startup */
+}
+
+/* Function callable from VxWorks shell to talk to Erlang - stop talking
+   and return to VxWorks shell through ^D (EOF) */
+to_erl()
+{
+    char buf[TBUFSIZ];
+    int cc;
+
+    if (masterfd == -1) {	/* sanity check */
+	fprintf(stderr, "Must start_erl first!\n");
+	return(-1);
+    }
+    while ((cc = read(0, buf, TBUFSIZ)) > 0) /* just pass everything through */
+	if (write(masterfd, buf, cc) != cc) {
+	    fprintf(stderr, "Write to Erlang failed!\n");
+	    return(-1);
+	}
+    return(cc);
+}