Initial commit

1 files changed, 38 insertions, 0 deletions

diff --git a/four/getch.c b/four/getch.c
new file mode 100644
index 0000000..84582ce
--- /dev/null
+++ b/four/getch.c
@@ -0,0 +1,38 @@
+#include <stdio.h>
+#include <string.h>
+
+#define BUFSIZE 101
+
+char buf[BUFSIZE];
+int bufp = 0;
+
+/*
+ * deliver the next character to be considered
+ * reading from the buffer if it contains a character
+ * and calling getchar if the buffer is empty
+ */
+int
+getch(void)
+{
+	return (bufp > 0) ? buf[--bufp] : getchar();
+}
+
+/* remember the characters put back on the input */
+void
+ungetch(int c)
+{
+	if (bufp >= BUFSIZE) {
+		printf("ungetch: too many characters\n");
+	} else {
+		buf[bufp++] = c;
+	}
+}
+
+void
+ungets(char s[])
+{
+	int l = strlen(s);
+	while (l) {
+		ungetch(s[--l]);
+	}
+}