OrionLibC

diff --git a/unistd/dup.c b/unistd/dup.c
new file mode 100644
index 0000000..a4aabfc
--- /dev/null
+++ b/unistd/dup.c
@@ -0,0 +1,28 @@
+#include <sys/syscall.h>
+#include <errno.h>
+
+/* Duplicate an open file descriptor */
+int
+dup(int oldfd)
+{
+	int ret;
+	asm volatile("int $0x80" : "=a" (ret) : "0" (SYSCALL_DUP),
+	             "c" (1), "S" (&oldfd));
+	if (ret >= 0)
+		return ret;
+	errno = -ret;
+	return -1;
+}
+
+/* Duplicate an open file descriptor to a specified file descriptor */
+int
+dup2(int oldfd, int newfd)
+{
+	int ret;
+	asm volatile("int $0x80" : "=a" (ret) : "0" (SYSCALL_DUP2),
+	             "c" (2), "S" (&oldfd));
+	if (ret >= 0)
+		return ret;
+	errno = -ret;
+	return -1;
+}