X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=fd.c;h=c675aaffd4b99083d3ab0e26445574c2b87ad51b;hb=40de1dd2fdbb054444d585aa70e2d50166a66e07;hp=d0b5c895a5f25d02b9f566fbe693a38898057203;hpb=07dd05be81f44b0af666a8bccf0a19ffff371db1;p=paraslash.git

diff --git a/fd.c b/fd.c
index d0b5c895..c675aaff 100644
--- a/fd.c
+++ b/fd.c
@@ -427,3 +427,24 @@ again:
 		goto again;
 	return ret;
 }
+
+/**
+ * Ensure that file descriptors 0, 1, and 2 are valid.
+ *
+ * Common approach that opens /dev/null until it gets a file descriptor greater
+ * than two.
+ *
+ * \sa okir's Black Hats Manual.
+ */
+void valid_fd_012(void)
+{
+	while (1) {
+		int fd = open("/dev/null", O_RDWR);
+		if (fd < 0)
+			exit(EXIT_FAILURE);
+		if (fd > 2) {
+			close(fd);
+			break;
+		}
+	}
+}