1 files changed, 24 insertions, 0 deletions
diff --git a/libpatch_is_devnull.c b/libpatch_is_devnull.c
new file mode 100644
index 0000000..3a78ea6
--- /dev/null
+++ b/libpatch_is_devnull.c
@@ -0,0 +1,24 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#include <sys/sysmacros.h>
+
+
+int
+libpatch_is_devnull(int fd)
+{
+	struct stat fd_st;
+#ifndef __linux__
+	struct stat null_st;
+#endif
+	if (fstat(fd, &fd_st))
+		return -1;
+	if (!S_ISCHR(fd_st.st_mode))
+		return 0;
+#ifdef __linux__
+	return fd_st.st_rdev == makedev(1, 3);
+#else
+	if (stat("/dev/null", &null_st))
+		return -1;
+	return fd_st.st_rdev == null_st.st_rdev;
+#endif
+}