diff --git a/src/input.cpp b/src/input.cpp
new file mode 100644
index 0000000..f93c46d
--- /dev/null
+++ b/src/input.cpp
@@ -0,0 +1,71 @@
+#include "string.h"
+#include "input.hpp"
+
+vector<string>* Input::_acWords = nullptr;
+
+Input::Input(string& entry, vector<string>& autocompletionWords, string prompt, string mlPrompt) : status(cont) {
+    char* c_entry;
+    bool multiline = false;
+    int entry_len;
+
+    _acWords = &autocompletionWords;
+
+    // linenoise for entry
+    linenoiseSetCompletionCallback(entry_completion_generator);
+    while (status == cont) {
+        // get user entry
+        if (multiline)
+            c_entry = linenoise(mlPrompt.c_str(), &entry_len);
+        else
+            c_entry = linenoise(prompt.c_str(), &entry_len);
+
+        // Ctrl-C
+        if (linenoiseKeyType() == 1) {
+            if (entry_len > 0 || multiline)
+                status = abort;
+            else
+                status = ctrlc;
+        } else if (linenoiseKeyType() == 3) {
+            multiline = true;
+            if (c_entry != nullptr) entry += c_entry;
+            entry += " ";
+        } else {
+            if (c_entry != nullptr) {
+                entry += c_entry;
+                // keep history
+                if (c_entry[0] != 0) (void)linenoiseHistoryAdd(entry.c_str());
+                status = ok;
+            } else
+                status = error;
+        }
+    }
+}
+
+/// @brief completion callback as asked by linenoise-ng
+/// this is called by linenoise-ng whenever the user enters TAB
+///
+/// @param text the text after wich the user entered TAB
+/// @param lc the completion object to add strings with linenoiseAddCompletion()
+///
+void Input::entry_completion_generator(const char* text, linenoiseCompletions* lc) {
+    if (Input::_acWords == nullptr || text == nullptr)
+        return;
+    
+    int text_len = strnlen(text, 6);
+
+    // propose all keywords
+    if (text_len == 0)
+        for (string& ac : *Input::_acWords)
+            // add all keywords
+            linenoiseAddCompletion(lc, ac.c_str());
+    // propose keywords matching to text begining
+    else
+        for (string& ac : *Input::_acWords)
+            // compare list entry with text, return if match
+            if (ac.compare(0, text_len, text) == 0) linenoiseAddCompletion(lc, ac.c_str());
+}
+
+void Input::preload(const char* preloadText) {
+    if (preloadText != nullptr)
+        linenoisePreloadBuffer(preloadText);
+}
diff --git a/src/input.hpp b/src/input.hpp
new file mode 100644
index 0000000..55a7b23
--- /dev/null
+++ b/src/input.hpp
@@ -0,0 +1,23 @@
+#ifndef _ENTRY_HPP_
+#define _ENTRY_HPP_
+
+#include <string>
+#include <vector>
+using namespace std;
+
+#include <cstdio>
+#include "linenoise.h"
+
+class Input {
+   public:
+    Input(string& entry, vector<string>& autocompletionWords, string prompt = "rpn> ", string mlPrompt = ">");
+    enum {ok, cont, abort, ctrlc, error} status;
+
+    static void preload(const char* preloadText);
+
+   private:
+    static void entry_completion_generator(const char* text, linenoiseCompletions* lc);
+    static vector<string>* _acWords;
+};
+
+#endif