feat: port lua scripting language

programs/include/libc/signal.h

@@ -0,0 +1,26 @@
+#ifndef _LIBC_SIGNAL_H
+#define _LIBC_SIGNAL_H
+
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef int sig_atomic_t;
+typedef void (*sighandler_t)(int);
+
+#define SIGINT 2
+
+#define SIG_DFL ((sighandler_t)0)
+#define SIG_IGN ((sighandler_t)1)
+#define SIG_ERR ((sighandler_t)-1)
+
+sighandler_t signal(int sig, sighandler_t handler);
+int          raise(int sig);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _LIBC_SIGNAL_H */