diff --git a/src/inputHandling.c b/src/inputHandling.c
index d4f4446..8479485 100644
--- a/src/inputHandling.c
+++ b/src/inputHandling.c
@@ -2,25 +2,22 @@
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
-#define STRINGL 200
 
-char a[STRINGL];
-void deleteWhitespace();
+
+char data[1000];
+void deleteWhitespace(char* a, int length);
 op readFunction(char* data, int length);
 char* getnumbers(char* data, int length, calc_op* structure_ref);
 void printstruct(calc_op* formula);
 
 
-void input() {
-    printf("Geben Sie eine Rechenoperation ein (Bsp.: 1+1):\n");
-    fgets(a, STRINGL, stdin);     //fgets statt scanf, holt den kompletten String inkl. Whitespace
-    deleteWhitespace();
+void input(char* a, int length) {
+    deleteWhitespace(a, length);
     calc_op temp;
-    char data[STRINGL];
-    memcpy(data,a,STRINGL);
+    memcpy(data,a,length);
     temp.formel = a;
     temp.funktionstyp = readFunction(data, 10);
-    if (getnumbers(data,STRINGL, &temp) == NULL){
+    if (getnumbers(data,length, &temp) == NULL){
         printstruct(&temp);
     } else {
         printf("Formular %s not supported", temp.formel);
@@ -28,10 +25,10 @@ void input() {
 }
 
 //Leerzeichen löschen
-void deleteWhitespace(){
-    for(int i=0; i<STRINGL; i++){
+void deleteWhitespace(char* a, int length){
+    for(int i=0; i<length; i++){
         if((a[i]==' ')||(a[i]=='\n')||(a[i]=='\r')){
-            for (int j=i; j<STRINGL; j++){
+            for (int j=i; j<length; j++){
            a[j]=a[j+1];
             }
         }
diff --git a/src/inputHandling.h b/src/inputHandling.h
index 71bd8f1..92ace40 100644
--- a/src/inputHandling.h
+++ b/src/inputHandling.h
@@ -15,7 +15,7 @@ void* parent;
 double result;
 }calc_op;
 
-extern void input();
-
+extern void input(char* a, int length);
+extern void printstruct(calc_op* formula);
 
 #endif // INPUTHANDLING_H
diff --git a/src/main.c b/src/main.c
index 1bca401..23d049e 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,6 +1,14 @@
 #include "helloWorld.h"
 #include "inputHandling.h"
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#define STRINGL 200
+
+char a[STRINGL] = {0};
 
 void main() {
-    input();
+    printf("Geben Sie eine Rechenoperation ein (Bsp.: 1+1):\n");
+    fgets(a, STRINGL, stdin);     //fgets statt scanf, holt den kompletten String inkl. Whitespace
+    input(a, strlen(a));
 }