Imported to git.

1 files changed, 50 insertions, 0 deletions

diff --git a/src/common/open_stdxxx.h b/src/common/open_stdxxx.h
new file mode 100644
index 00000000..d0ac15af
--- /dev/null
+++ b/src/common/open_stdxxx.h
@@ -0,0 +1,50 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       open_stdxxx.h
+/// \brief      Make sure that file descriptors 0, 1, and 2 are open
+//
+//  This code has been put into the public domain.
+//
+//  This library is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef OPEN_STDXXX_H
+#define OPEN_STDXXX_H
+
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+
+static void
+open_stdxxx(int status)
+{
+	for (int i = 0; i <= 2; ++i) {
+		// We use fcntl() to check if the file descriptor is open.
+		if (fcntl(i, F_GETFD) == -1 && errno == EBADF) {
+			// With stdin, we could use /dev/full so that
+			// writing to stdin would fail. However, /dev/full
+			// is Linux specific, and if the program tries to
+			// write to stdin, there's already a problem anyway.
+			const int fd = open("/dev/null", O_NOCTTY
+					| (i == 0 ? O_WRONLY : O_RDONLY));
+
+			if (fd != i) {
+				// Something went wrong. Exit with the
+				// exit status we were given. Don't try
+				// to print an error message, since stderr
+				// may very well be non-existent. This
+				// error should be extremely rare.
+				(void)close(fd);
+				exit(status);
+			}
+		}
+	}
+
+	return;
+}
+
+#endif