lesson 21, keyboard input and shell

21-shell/libc/string.h

@@ -0,0 +1,10 @@
+#ifndef STRINGS_H
+#define STRINGS_H
+
+void int_to_ascii(int n, char str[]);
+void reverse(char s[]);
+int strlen(char s[]);
+void append(char s[], char n);
+int strcmp(char s1[], char s2[]);
+
+#endif