diff --git a/assignments/shell/AddUsers/addUsers.sh b/assignments/shell/AddUsers/addUsers.sh
old mode 100644
new mode 100755
index 2905c24..f357a4b
--- a/assignments/shell/AddUsers/addUsers.sh
+++ b/assignments/shell/AddUsers/addUsers.sh
@@ -1,9 +1,17 @@
-#
-#
-# useradd
-# chpasswd
-# chown
-# chmod
-# edquota
-#
-
+#!/usr/bin/env bash
+# useradd
+# chpasswd
+# chown
+# chmod
+# edquota
+#
+case $1 in
+    'clean') for u in $(cat users.txt)
+            do sudo userdel $u
+        done
+    ;;
+    *) for u in $(cat users.txt)
+            do sudo useradd $u
+        done
+    ;;
+esac
diff --git a/experiments/gcc-1-hello-world/main.c b/experiments/gcc-1-hello-world/main.c
deleted file mode 100644
index abfd4b3..0000000
--- a/experiments/gcc-1-hello-world/main.c
+++ /dev/null
@@ -1,6 +0,0 @@
-#include <stdio.h>
-
-int main(void) {
-	printf("Hello world!\n");
-	return 0;
-}
diff --git a/experiments/gcc-2-multi-source/calculator.c b/experiments/gcc-2-multi-source/calculator.c
deleted file mode 100644
index 391fc7f..0000000
--- a/experiments/gcc-2-multi-source/calculator.c
+++ /dev/null
@@ -1,17 +0,0 @@
-#include "include/calculator.h"
-
-int sum(int x, int y) {
-	return x + y;
-}
-
-int subtract(int x, int y) {
-	return x - y;
-}
-
-int multiply(int x, int y) {
-	return x * y;
-}
-
-int divide(int x, int divisor) {
-	return x / divisor;
-}
diff --git a/experiments/gcc-2-multi-source/include/calculator.h b/experiments/gcc-2-multi-source/include/calculator.h
deleted file mode 100644
index 7daefe5..0000000
--- a/experiments/gcc-2-multi-source/include/calculator.h
+++ /dev/null
@@ -1,6 +0,0 @@
-
-int sum(int x, int y);
-int subtract(int x, int y);
-int multiply(int x, int y);
-int divide(int x, int divisor);
-
diff --git a/experiments/gcc-2-multi-source/main.c b/experiments/gcc-2-multi-source/main.c
deleted file mode 100644
index bdbb5b9..0000000
--- a/experiments/gcc-2-multi-source/main.c
+++ /dev/null
@@ -1,12 +0,0 @@
-#include <stdio.h>
-
-int main(void) {
-	int x, y;
-	
-	x = 2;
-	y = 3;
-
-	printf("%d + %d = %d\n", x, y, sum(2, 3));
-
-	return 0;
-}
diff --git a/experiments/gcc-3-real-project/Makefile b/experiments/gcc-3-real-project/Makefile
deleted file mode 100644
index 0531065..0000000
--- a/experiments/gcc-3-real-project/Makefile
+++ /dev/null
@@ -1,9 +0,0 @@
-main:main.o calculator.o
-	gcc main.o calculator.o -o main
-main.o:main.c
-	gcc -c main.c
-calculator.o:calculator.c
-	gcc -c calculator.c
-
-clean:
-	rm main *.o
diff --git a/experiments/gcc-3-real-project/calculator.c b/experiments/gcc-3-real-project/calculator.c
deleted file mode 100644
index 391fc7f..0000000
--- a/experiments/gcc-3-real-project/calculator.c
+++ /dev/null
@@ -1,17 +0,0 @@
-#include "include/calculator.h"
-
-int sum(int x, int y) {
-	return x + y;
-}
-
-int subtract(int x, int y) {
-	return x - y;
-}
-
-int multiply(int x, int y) {
-	return x * y;
-}
-
-int divide(int x, int divisor) {
-	return x / divisor;
-}
diff --git a/experiments/gcc-3-real-project/include/calculator.h b/experiments/gcc-3-real-project/include/calculator.h
deleted file mode 100644
index a5e00e3..0000000
--- a/experiments/gcc-3-real-project/include/calculator.h
+++ /dev/null
@@ -1,9 +0,0 @@
-#ifndef _CALC_H
-#define _CALC_H
-
-int sum(int x, int y);
-int subtract(int x, int y);
-int multiply(int x, int y);
-int divide(int x, int divisor);
-
-#endif //_CALC_H
diff --git a/experiments/gcc-3-real-project/main.c b/experiments/gcc-3-real-project/main.c
deleted file mode 100644
index 6798996..0000000
--- a/experiments/gcc-3-real-project/main.c
+++ /dev/null
@@ -1,14 +0,0 @@
-#include <stdio.h>
-
-#include "include/calculator.h"
-
-int main(void) {
-	int x, y;
-	
-	x = 2;
-	y = 3;
-
-	printf("%d - %d = %d\n", x, y, subtract(2, 3));
-
-	return 0;
-}
diff --git a/experiments/gcc-4-optimize/Makefile b/experiments/gcc-4-optimize/Makefile
deleted file mode 100644
index 121d85a..0000000
--- a/experiments/gcc-4-optimize/Makefile
+++ /dev/null
@@ -1,36 +0,0 @@
-result:main array calculator
-	gcc main.o array.o calculator.o -o result
-
-main: main_clean main.c
-	gcc -c -O0 main.c
-main_optimize: main_clean main.c
-	gcc -c -O2 main.c
-main_clean:
-	if [ -e main.o ] ; then rm main.o ; fi
-	
-
-calculator:calculator.c
-	gcc -c calculator.c
-
-array: array_clean array.c
-	gcc -c -O0 array.c
-array_optimize: array_clean array.c
-	gcc -c -O2 array.c
-array_clean:
-	if [ -e array.o ] ; then rm array.o ; fi
-	
-
-release: main_optimize array_optimize calculator
-	gcc main.o array.o -o release
-
-diff: result release
-	./result
-	./release
-
-clean:
-	if [ -e result ] ; then rm result ; fi
-
-	if [ -e release ] ; then rm release ; fi
-
-	rm *.o
-
diff --git a/experiments/gcc-4-optimize/array.c b/experiments/gcc-4-optimize/array.c
deleted file mode 100644
index e92db61..0000000
--- a/experiments/gcc-4-optimize/array.c
+++ /dev/null
@@ -1,26 +0,0 @@
-#include <stdio.h>
-
-#include "include/array.h"
-
-void array_fill_with(int *array, int length, int fillWith) {
-	int i;
-	for (i = 0; i < length; i++) {
-		array[i] = fillWith;
-	}
-}
-
-void array_add(int *arrayX, int *arrayY, int *arrayZ, int length) {
-	int i;
-	for (i = 0; i < length; i++) {
-		arrayZ[i] = arrayX[i] + arrayY[i];
-	}
-}
-
-void array_print(int *array, int length) {
-	int i;
-	for (i =0; i < length; i++) {
-		printf("%d\t", array[i]);
-	}
-	
-	printf("\n");
-}
diff --git a/experiments/gcc-4-optimize/calculator.c b/experiments/gcc-4-optimize/calculator.c
deleted file mode 100644
index 391fc7f..0000000
--- a/experiments/gcc-4-optimize/calculator.c
+++ /dev/null
@@ -1,17 +0,0 @@
-#include "include/calculator.h"
-
-int sum(int x, int y) {
-	return x + y;
-}
-
-int subtract(int x, int y) {
-	return x - y;
-}
-
-int multiply(int x, int y) {
-	return x * y;
-}
-
-int divide(int x, int divisor) {
-	return x / divisor;
-}
diff --git a/experiments/gcc-4-optimize/include/array.h b/experiments/gcc-4-optimize/include/array.h
deleted file mode 100644
index 3f079f4..0000000
--- a/experiments/gcc-4-optimize/include/array.h
+++ /dev/null
@@ -1,9 +0,0 @@
-#ifndef _ARRAY_H
-#define _ARRAY_H
-
-void array_fill_with(int *array, int length, int fillWith);
-void array_print(int *array, int length);
-
-void array_add(int *arrayX, int *arrayY, int *arrayZ, int length);
-
-#endif
diff --git a/experiments/gcc-4-optimize/include/calculator.h b/experiments/gcc-4-optimize/include/calculator.h
deleted file mode 100644
index a5e00e3..0000000
--- a/experiments/gcc-4-optimize/include/calculator.h
+++ /dev/null
@@ -1,9 +0,0 @@
-#ifndef _CALC_H
-#define _CALC_H
-
-int sum(int x, int y);
-int subtract(int x, int y);
-int multiply(int x, int y);
-int divide(int x, int divisor);
-
-#endif //_CALC_H
diff --git a/experiments/gcc-4-optimize/main.c b/experiments/gcc-4-optimize/main.c
deleted file mode 100644
index 7f314ff..0000000
--- a/experiments/gcc-4-optimize/main.c
+++ /dev/null
@@ -1,32 +0,0 @@
-#include <stdio.h>
-#include <time.h>
-
-#include "include/calculator.h"
-
-#include "include/array.h"
-
-#define VECTOR_LENGTH 2048
-
-int main(void) {
-
-	int vector_a[VECTOR_LENGTH], vector_b[VECTOR_LENGTH], vector_c[VECTOR_LENGTH];
-
-	double time_start, time_end;	
-	array_fill_with(vector_a, VECTOR_LENGTH, 10);
-	array_fill_with(vector_b, VECTOR_LENGTH, 55);
-
-	time_start = clock();
-	
-	array_add(vector_a, vector_b, vector_c, VECTOR_LENGTH);
-
-	time_end = clock();
-
-	//array_print(vector_c, VECTOR_LENGTH);
-	
-	printf("Time used: %10.9f\n", (double) ( (time_end - time_start) / 1000.0) );
-
-	return 0;
-}
-
-
-
diff --git a/experiments/gcc-5-gdb/Makefile b/experiments/gcc-5-gdb/Makefile
deleted file mode 100644
index a49a825..0000000
--- a/experiments/gcc-5-gdb/Makefile
+++ /dev/null
@@ -1,33 +0,0 @@
-result:main array
-	gcc main.o array.o -o result
-
-main: main_clean main.c
-	gcc -c -O0 main.c
-main_optimize: main_clean main.c
-	gcc -c -O2 main.c
-main_clean:
-	if [ -e main.o ] ; then rm main.o ; fi
-	
-
-array: array_clean array.c
-	gcc -c -O0 array.c
-array_optimize: array_clean array.c
-	gcc -c -O2 array.c
-array_clean:
-	if [ -e array.o ] ; then rm array.o ; fi
-	
-
-release: main_optimize array_optimize
-	gcc main.o array.o -o release
-
-diff: result release
-	./result
-	./release
-
-clean:
-	if [ -e result ] ; then rm result ; fi
-
-	if [ -e release ] ; then rm release ; fi
-
-	rm *.o
-
diff --git a/experiments/gcc-5-gdb/array.c b/experiments/gcc-5-gdb/array.c
deleted file mode 100644
index f12c568..0000000
--- a/experiments/gcc-5-gdb/array.c
+++ /dev/null
@@ -1,26 +0,0 @@
-#include <stdio.h>
-
-#include "include/array.h"
-
-void array_fill_with(int *array, int length, int fillWith) {
-	int i;
-	for (i = 0; i <= length; i++) {
-		array[i] = fillWith;
-	}
-}
-
-void array_add(int *arrayX, int *arrayY, int *arrayZ, int length) {
-	int i;
-	for (i = 0; i <= length; i++) {
-		arrayZ[i] = arrayX[i] + arrayY[i];
-	}
-}
-
-void array_print(int *array, int length) {
-	int i;
-	for (i =0; i < length; i++) {
-		printf("%d\t", array[i]);
-	}
-	
-	printf("\n");
-}
diff --git a/experiments/gcc-5-gdb/include/array.h b/experiments/gcc-5-gdb/include/array.h
deleted file mode 100644
index 3f079f4..0000000
--- a/experiments/gcc-5-gdb/include/array.h
+++ /dev/null
@@ -1,9 +0,0 @@
-#ifndef _ARRAY_H
-#define _ARRAY_H
-
-void array_fill_with(int *array, int length, int fillWith);
-void array_print(int *array, int length);
-
-void array_add(int *arrayX, int *arrayY, int *arrayZ, int length);
-
-#endif
diff --git a/experiments/gcc-5-gdb/main.c b/experiments/gcc-5-gdb/main.c
deleted file mode 100644
index f6ff3da..0000000
--- a/experiments/gcc-5-gdb/main.c
+++ /dev/null
@@ -1,24 +0,0 @@
-#include <stdio.h>
-
-#include "include/array.h"
-
-#define VECTOR_LENGTH 16
-
-int main(void) {
-
-	int vector_a[VECTOR_LENGTH], vector_b[VECTOR_LENGTH], vector_c[VECTOR_LENGTH];
-
-	array_fill_with(vector_a, VECTOR_LENGTH, 10);
-	array_fill_with(vector_b, VECTOR_LENGTH, 55);
-
-	
-	array_add(vector_a, vector_b, vector_c, VECTOR_LENGTH);
-
-
-	array_print(vector_c, VECTOR_LENGTH);
-	
-	return 0;
-}
-
-
-