feat: implemented pipes and redirects + background operator

scanner.c

@@ -7,7 +7,17 @@
 
 #include "scanner.h"
 
-//TODO: handle EOF more completely (currently only EOF at the start of the line is handled)
+#if EXT_PROMPT
+#include <readline/readline.h>
+
+/**
+ * Reads an inputline from stdin.
+ * @return a string containing the inputline.
+ */
+char *readInputLine(char const *prompt) {
+  return readline(prompt);
+}
+#else
 /**
  * Reads an inputline from stdin.
  * @return a string containing the inputline.
@@ -43,6 +53,7 @@ char *readInputLine() {
     s[i] = '\0';
     return s;
 }
+#endif
 
 /**
  * The function isOperatorCharacter checks whether the input paramater \param c is an operator.