implemented getstr

src/userinput.c

@@ -3,6 +3,7 @@
 #include <ctype.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 void trimLeft(char *input) {
     size_t length = strlen(input);
@@ -46,4 +47,26 @@ char *readInput() {
     trimLeft(buffer);
     trimRight(buffer);
     return buffer;
+}
+
+char *getstr(char *message, unsigned long *minLength, unsigned long *maxLength) {
+    printf("%s", message);
+    fflush(stdout);
+    char *result = readInput();
+    while (minLength != NULL && strlen(result) < *minLength || maxLength != NULL && strlen(result) > *maxLength) {
+        printf("%s", "Ungueltige Eingabe! ");
+        if (minLength != NULL && maxLength == NULL) {
+            printf("Die Eingabe muss mind. %lu Zeichen lang sein.\n", *minLength);
+        }
+        else if (maxLength != NULL && minLength == NULL) {
+            printf("Die Eingabe darf maximal %lu Zeichen lang sein.\n", *maxLength);
+        }
+        else {
+            printf("Die Eingabe muss %lu bis %lu Zeichen lang sein.\n", *minLength, *maxLength);
+        }
+        printf("%s", message);
+        fflush(stdout);
+        result = readInput();
+    }
+    return result;
 }