Add function for finding what a InputStream or OutputStream is attached to

runtime/bin/socket_linux.cc

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/stat.h>
 #include <unistd.h>
 
 #include "bin/fdutils.h"
+#include "bin/file.h"
 #include "bin/log.h"
 #include "bin/socket.h"
 
 
 bool Socket::Initialize() {
   // Nothing to do on Linux.
   return true;
 }
 
 
@@ skipping 110 matching lines @@
   int len = sizeof(errno);
   getsockopt(fd,
              SOL_SOCKET,
              SO_ERROR,
              &errno,
              reinterpret_cast<socklen_t*>(&len));
   os_error->SetCodeAndMessage(OSError::kSystem, errno);
 }
 
 
+int Socket::GetType(intptr_t fd) {
+  struct stat buf;
+  if (isatty(fd)) return File::kTerminal;
+  int result = fstat(fd, &buf);
+  if (result == -1) return -1;
+  if (S_ISFIFO(buf.st_mode)) return File::kPipe;
+  if (S_ISREG(buf.st_mode)) return File::kFile;
+  return File::kOther;
+}
+
+
 intptr_t Socket::GetStdioHandle(int num) {
   return static_cast<intptr_t>(num);
 }
 
 
 const char* Socket::LookupIPv4Address(char* host, OSError** os_error) {
   // Perform a name lookup for an IPv4 address.
   struct addrinfo hints;
   memset(&hints, 0, sizeof(hints));
   hints.ai_family = AF_INET;
@@ skipping 92 matching lines @@
       // error. We got woken up from the poll on the listening socket,
       // but there is no connection ready to be accepted.
       ASSERT(kTemporaryFailure != -1);
       socket = kTemporaryFailure;
     }
   } else {
     FDUtils::SetNonBlocking(socket);
   }
   return socket;
 }