* configure.in: check dup3.

* io.c (rb_cloexec_dup2): use dup3 if available.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@33561 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 15 insertions, 0 deletions

diff --git a/io.c b/io.c
index fadbb2ec90..5bec3622f4 100644
--- a/io.c
+++ b/io.c
@@ -232,7 +232,22 @@ rb_cloexec_dup2(int oldfd, int newfd)
 {
     int ret;
 
+#if defined(HAVE_DUP3) && defined(O_CLOEXEC)
+    static int try_dup3 = 1;
+    if (try_dup3) {
+        ret = dup3(oldfd, newfd, O_CLOEXEC);
+        /* dup3 is available since Linux 2.6.27. */
+        if (ret == -1 && errno == ENOSYS) {
+            try_dup3 = 0;
+            ret = dup2(oldfd, newfd);
+        }
+    }
+    else {
+        ret = dup2(oldfd, newfd);
+    }
+#else
     ret = dup2(oldfd, newfd);
+#endif
     if (ret == -1) return -1;
     fd_set_cloexec(ret);
     return ret;