1 files changed, 22 insertions, 0 deletions
diff --git a/5.20/getch.c b/5.20/getch.c
new file mode 100644
index 0000000..e41671e
--- /dev/null
+++ b/5.20/getch.c
@@ -0,0 +1,22 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include "err.h"
+#include "getch.h"
+
+#define MAXBUFF	100
+
+char buff[MAXBUFF];
+static size_t top;
+
+void ungetch(char c)
+{
+	if (top < MAXBUFF)
+		buff[top++] = c;
+	else
+		err("buff: stack overflow");
+}
+
+char getch(void)
+{
+	return (top > 0) ? buff[--top] : getchar();
+}