unistr/u*-chr: test multibyte sequences

[gnulib.git] / lib / pipe2.c

diff --git a/lib/pipe2.c b/lib/pipe2.c
index 726813f..2d973dc 100644 (file)
--- a/lib/pipe2.c
+++ b/lib/pipe2.c
@@ -1,5 +1,5 @@
 /* Create a pipe, with specific opening flags.
-   Copyright (C) 2009 Free Software Foundation, Inc.
+   Copyright (C) 2009, 2010 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -23,14 +23,48 @@
 #include <errno.h>
 #include <fcntl.h>
 
+#include "binary-io.h"
+
 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
 /* Native Woe32 API.  */
 
 # include <io.h>
 
+#else
+/* Unix API.  */
+
+# ifndef O_CLOEXEC
+#  define O_CLOEXEC 0
+# endif
+
+#endif
+
 int
 pipe2 (int fd[2], int flags)
 {
+#if HAVE_PIPE2
+# undef pipe2
+  /* Try the system call first, if it exists.  (We may be running with a glibc
+     that has the function but with an older kernel that lacks it.)  */
+  {
+    /* Cache the information whether the system call really exists.  */
+    static int have_pipe2_really; /* 0 = unknown, 1 = yes, -1 = no */
+    if (have_pipe2_really >= 0)
+      {
+        int result = pipe2 (fd, flags);
+        if (!(result < 0 && errno == ENOSYS))
+          {
+            have_pipe2_really = 1;
+            return result;
+          }
+        have_pipe2_really = -1;
+      }
+  }
+#endif
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Native Woe32 API.  */
+
   /* Check the supported flags.  */
   if ((flags & ~(O_CLOEXEC | O_BINARY | O_TEXT)) != 0)
     {
@@ -39,18 +73,10 @@ pipe2 (int fd[2], int flags)
     }
 
   return _pipe (fd, 4096, flags);
-}
 
 #else
 /* Unix API.  */
 
-# ifndef O_CLOEXEC
-#  define O_CLOEXEC 0
-# endif
-
-int
-pipe2 (int fd[2], int flags)
-{
   /* Check the supported flags.  */
   if ((flags & ~(O_CLOEXEC | O_NONBLOCK | O_TEXT | O_BINARY)) != 0)
     {
@@ -70,10 +96,10 @@ pipe2 (int fd[2], int flags)
       int fcntl_flags;
 
       if ((fcntl_flags = fcntl (fd[1], F_GETFL, 0)) < 0
-         || fcntl (fd[1], F_SETFL, fcntl_flags | O_NONBLOCK) == -1
-         || (fcntl_flags = fcntl (fd[0], F_GETFL, 0)) < 0
-         || fcntl (fd[0], F_SETFL, fcntl_flags | O_NONBLOCK) == -1)
-       goto fail;
+          || fcntl (fd[1], F_SETFL, fcntl_flags | O_NONBLOCK) == -1
+          || (fcntl_flags = fcntl (fd[0], F_GETFL, 0)) < 0
+          || fcntl (fd[0], F_SETFL, fcntl_flags | O_NONBLOCK) == -1)
+        goto fail;
     }
 
   if (flags & O_CLOEXEC)
@@ -81,13 +107,13 @@ pipe2 (int fd[2], int flags)
       int fcntl_flags;
 
       if ((fcntl_flags = fcntl (fd[1], F_GETFD, 0)) < 0
-         || fcntl (fd[1], F_SETFD, fcntl_flags | FD_CLOEXEC) == -1
-         || (fcntl_flags = fcntl (fd[0], F_GETFD, 0)) < 0
-         || fcntl (fd[0], F_SETFD, fcntl_flags | FD_CLOEXEC) == -1)
-       goto fail;
+          || fcntl (fd[1], F_SETFD, fcntl_flags | FD_CLOEXEC) == -1
+          || (fcntl_flags = fcntl (fd[0], F_GETFD, 0)) < 0
+          || fcntl (fd[0], F_SETFD, fcntl_flags | FD_CLOEXEC) == -1)
+        goto fail;
     }
 
-#if O_BINARY
+# if O_BINARY
   if (flags & O_BINARY)
     {
       setmode (fd[1], O_BINARY);
@@ -98,7 +124,7 @@ pipe2 (int fd[2], int flags)
       setmode (fd[1], O_TEXT);
       setmode (fd[0], O_TEXT);
     }
-#endif
+# endif
 
   return 0;
 
@@ -110,6 +136,6 @@ pipe2 (int fd[2], int flags)
     errno = saved_errno;
     return -1;
   }
-}
 
 #endif
+}