diff --git a/Parser/intrcheck.c b/Parser/intrcheck.c
new file mode 100644
index 0000000..f963208
--- /dev/null
+++ b/Parser/intrcheck.c
@@ -0,0 +1,95 @@
+/* Check for interrupts */
+
+#ifdef MSDOS
+
+/* This might work for MS-DOS: */
+
+void
+initintr()
+{
+}
+
+int
+intrcheck()
+{
+	int interrupted = 0;
+	while (kbhit()) {
+		if (getch() == '\003')
+			interrupted = 1;
+	}
+	return interrupted;
+}
+
+#define OK
+
+#endif
+
+
+#ifdef THINK_C
+
+#include <MacHeaders>
+
+void
+initintr()
+{
+}
+
+int
+intrcheck()
+{
+	/* Static to make it faster(?) only */
+	static EventRecord e;
+	
+	/* XXX This fails if the user first types ahead and then
+	   decides to interrupt -- repeating Command-. until the
+	   event queue overflows may work though. */
+	if (EventAvail(keyDownMask|autoKeyMask, &e) &&
+				(e.modifiers & cmdKey) &&
+				(e.message & charCodeMask) == '.') {
+		(void) GetNextEvent(keyDownMask|autoKeyMask, &e);
+		return 1;
+	}
+	return 0;
+}
+
+#define OK
+
+#endif /* THINK_C */
+
+
+#ifndef OK
+
+/* Default version -- should work for Unix and Standard C */
+
+#include <stdio.h>
+#include <signal.h>
+
+#include "sigtype.h"
+
+static int interrupted;
+
+static SIGTYPE
+intcatcher(sig)
+	int sig;
+{
+	interrupted = 1;
+	signal(SIGINT, intcatcher);
+}
+
+void
+initintr()
+{
+	if (signal(SIGINT, SIG_IGN) != SIG_IGN)
+		signal(SIGINT, intcatcher);
+}
+
+int
+intrcheck()
+{
+	if (!interrupted)
+		return 0;
+	interrupted = 0;
+	return 1;
+}
+
+#endif /* !OK */