first draft

signal.c

@@ -0,0 +1,29 @@
+/* protable signal() like */
+
+#include <signal.h>
+
+/* Portable signal() from R.Stevens,
+ * modified to reset the handler */
+void (*Signal(int signo, void (*func)(int)))(int)
+{
+	struct sigaction act, oact;
+
+	act.sa_handler = func;
+	sigemptyset(&act.sa_mask);
+	act.sa_flags = 0; /* So if set SA_RESETHAND is cleared */
+	if (signo == SIGALRM)
+	{
+#ifdef SA_INTERRUPT
+		act.sa_flags |= SA_INTERRUPT;   /* SunOS 4.x */
+#endif
+	}
+	else
+	{
+#ifdef SA_RESTART
+		act.sa_flags |= SA_RESTART;     /* SVR4, 4.4BSD, Linux */
+#endif
+	}
+	if (sigaction(signo, &act, &oact) == -1)
+		return SIG_ERR;
+	return (oact.sa_handler);
+}