diff --git a/lib/array_list.h b/lib/array_list.h
index d82894e..7550670 100644
--- a/lib/array_list.h
+++ b/lib/array_list.h
@@ -1,6 +1,7 @@
 #ifndef __LIBCPROJECT_ARRAY_LIST__
 #define __LIBCPROJECT_ARRAY_LIST__
 
+#include <errno.h>
 #include <stdbool.h>
 #include <stdlib.h>
 
diff --git a/lib/character.h b/lib/character.h
index 527d24f..b42a9f1 100644
--- a/lib/character.h
+++ b/lib/character.h
@@ -1,6 +1,7 @@
 #ifndef __LIBCPROJECT_CHARACTER__
 #define __LIBCPROJECT_CHARACTER__
 
+#include <errno.h>
 #include <stdbool.h>
 #include <stdlib.h>
 
diff --git a/lib/convert.c b/lib/convert.c
index b084127..c39bc80 100644
--- a/lib/convert.c
+++ b/lib/convert.c
@@ -3,6 +3,7 @@
 string_t convert_character_to_string(const char character) {
   string_t string = malloc(sizeof(char) * 2);
   if (string == NULL) {
+    perror("Error (convert_character_to_string)");
     exit(EXIT_FAILURE);
   }
   string[0] = character;
@@ -44,6 +45,7 @@ string_t convert_number_to_string(const long long integer) {
   }
   string_t string = malloc(sizeof(char) * length);
   if (string == NULL) {
+    perror("Error (convert_number_to_string)");
     exit(EXIT_FAILURE);
   }
   current = mathematics_absolute_value(integer);
diff --git a/lib/convert.h b/lib/convert.h
index 9fb1cb1..1ebd899 100644
--- a/lib/convert.h
+++ b/lib/convert.h
@@ -1,6 +1,7 @@
 #ifndef __LIBCPROJECT_CONVERT__
 #define __LIBCPROJECT_CONVERT__
 
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 
diff --git a/lib/hash_map.h b/lib/hash_map.h
index 02cab60..217dd83 100644
--- a/lib/hash_map.h
+++ b/lib/hash_map.h
@@ -1,6 +1,7 @@
 #ifndef __LIBCPROJECT_HASH_MAP__
 #define __LIBCPROJECT_HASH_MAP__
 
+#include <errno.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdlib.h>
diff --git a/lib/linked_list.c b/lib/linked_list.c
index e505b28..032fcce 100644
--- a/lib/linked_list.c
+++ b/lib/linked_list.c
@@ -3,6 +3,7 @@
 struct linked_list *linked_list_initialization() {
   struct linked_list *list = malloc(sizeof(*list));
   if (list == NULL) {
+    perror("Error (linked_list_initialization)");
     exit(EXIT_FAILURE);
   }
   list->head = NULL;
@@ -11,8 +12,14 @@ struct linked_list *linked_list_initialization() {
 }
 
 struct linked_list_node *linked_list_add_in_head(struct linked_list *list, void *new_data) {
+  if (list == NULL) {
+    errno = EINVAL;
+    perror("Error (linked_list_add_in_head)");
+    exit(EXIT_FAILURE);
+  }
   struct linked_list_node *node_new = malloc(sizeof(*node_new));
-  if (list == NULL || node_new == NULL) {
+  if (node_new == NULL) {
+    perror("Error (linked_list_add_in_head)");
     exit(EXIT_FAILURE);
   }
   node_new->data = new_data;
@@ -24,6 +31,8 @@ struct linked_list_node *linked_list_add_in_head(struct linked_list *list, void
 
 void linked_list_delete_in_head(struct linked_list *list) {
   if (list == NULL) {
+    errno = EINVAL;
+    perror("Error (linked_list_delete_in_head)");
     exit(EXIT_FAILURE);
   }
   if (list->head != NULL) {
@@ -35,11 +44,17 @@ void linked_list_delete_in_head(struct linked_list *list) {
 }
 
 struct linked_list_node *linked_list_add_after_last(struct linked_list *list, void *new_data) {
+  if (list == NULL) {
+    errno = EINVAL;
+    perror("Error (linked_list_add_after_last)");
+    exit(EXIT_FAILURE);
+  }
   if (list->head == NULL) {
     return linked_list_add_in_head(list, new_data);
   }
   struct linked_list_node *node_new = malloc(sizeof(*node_new));
-  if (list == NULL || node_new == NULL) {
+  if (node_new == NULL) {
+    perror("Error (linked_list_add_after_last)");
     exit(EXIT_FAILURE);
   }
   node_new->data = new_data;
diff --git a/lib/linked_list.h b/lib/linked_list.h
index a736325..e79f48d 100644
--- a/lib/linked_list.h
+++ b/lib/linked_list.h
@@ -1,6 +1,7 @@
 #ifndef __LIBCPROJECT_LINKED_LIST__
 #define __LIBCPROJECT_LINKED_LIST__
 
+#include <errno.h>
 #include <stdbool.h>
 #include <stdlib.h>
 
diff --git a/lib/mathematics.h b/lib/mathematics.h
index ab0ac33..41f25ad 100644
--- a/lib/mathematics.h
+++ b/lib/mathematics.h
@@ -3,6 +3,7 @@
 
 #define MATHEMATICS_FLOAT_PRECISION 0.00000001
 
+#include <errno.h>
 #include <stdbool.h>
 
 #include "types.h"
diff --git a/lib/queue.c b/lib/queue.c
index cc8a464..d353c1d 100644
--- a/lib/queue.c
+++ b/lib/queue.c
@@ -3,6 +3,7 @@
 struct queue *queue_initialization() {
   struct queue *queue = malloc(sizeof(*queue));
   if (queue == NULL) {
+    perror("Error (queue_initialization)");
     exit(EXIT_FAILURE);
   }
   queue->first = NULL;
@@ -11,8 +12,14 @@ struct queue *queue_initialization() {
 }
 
 void queue_push(struct queue *queue, void *data) {
+  if (queue == NULL) {
+    errno = EINVAL;
+    perror("Error (queue_push)");
+    exit(EXIT_FAILURE);
+  }
   struct queue_node *node_new = malloc(sizeof(*node_new));
-  if (queue == NULL || node_new == NULL) {
+  if (node_new == NULL) {
+    perror("Error (queue_push)");
     exit(EXIT_FAILURE);
   }
   node_new->data = data;
@@ -31,6 +38,8 @@ void queue_push(struct queue *queue, void *data) {
 
 void *queue_pop(struct queue *queue) {
   if (queue == NULL) {
+    errno = EINVAL;
+    perror("Error (queue_pop)");
     exit(EXIT_FAILURE);
   }
   struct queue_node *node = queue->first;
@@ -46,6 +55,8 @@ void *queue_pop(struct queue *queue) {
 
 void queue_free(struct queue *queue) {
   if (queue == NULL) {
+    errno = EINVAL;
+    perror("Error (queue_free)");
     exit(EXIT_FAILURE);
   }
   struct queue_node *node = queue->first;
diff --git a/lib/queue.h b/lib/queue.h
index 40327d4..bd6c298 100644
--- a/lib/queue.h
+++ b/lib/queue.h
@@ -1,6 +1,7 @@
 #ifndef __LIBCPROJECT_QUEUE__
 #define __LIBCPROJECT_QUEUE__
 
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 
diff --git a/lib/stack.c b/lib/stack.c
index c8eb356..87746eb 100644
--- a/lib/stack.c
+++ b/lib/stack.c
@@ -3,6 +3,7 @@
 struct stack *stack_initialization() {
   struct stack *stack = malloc(sizeof(*stack));
   if (stack == NULL) {
+    perror("Error (stack_initialization)");
     exit(EXIT_FAILURE);
   }
   stack->first = NULL;
@@ -11,8 +12,14 @@ struct stack *stack_initialization() {
 }
 
 void stack_push(struct stack *stack, void *data) {
+  if (stack == NULL) {
+    errno = EINVAL;
+    perror("Error (stack_push)");
+    exit(EXIT_FAILURE);
+  }
   struct stack_node *node_new = malloc(sizeof(*node_new));
-  if (stack == NULL || data == NULL) {
+  if (data == NULL) {
+    perror("Error (stack_push)");
     exit(EXIT_FAILURE);
   }
   node_new->data = data;
@@ -23,6 +30,8 @@ void stack_push(struct stack *stack, void *data) {
 
 void *stack_pop(struct stack *stack) {
   if (stack == NULL) {
+    errno = EINVAL;
+    perror("Error (stack_pop)");
     exit(EXIT_FAILURE);
   }
   struct stack_node *node = stack->first;
@@ -38,6 +47,8 @@ void *stack_pop(struct stack *stack) {
 
 void stack_free(struct stack *stack) {
   if (stack == NULL) {
+    errno = EINVAL;
+    perror("Error (stack_free)");
     exit(EXIT_FAILURE);
   }
   struct stack_node *node = stack->first;
diff --git a/lib/stack.h b/lib/stack.h
index 1f0d354..724e9b1 100644
--- a/lib/stack.h
+++ b/lib/stack.h
@@ -1,6 +1,7 @@
 #ifndef __LIBCPROJECT_STACK__
 #define __LIBCPROJECT_STACK__
 
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 
diff --git a/lib/string.c b/lib/string.c
index 5ca2ef1..4d3fdbb 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -67,6 +67,7 @@ string_t string_copy(const string_t string) {
   size_t source_length = string_get_length(string);
   string_t copy = malloc(sizeof(char) * (source_length + 1));
   if (copy == NULL) {
+    perror("Error (string_copy)");
     exit(EXIT_FAILURE);
   }
   size_t index;
@@ -150,6 +151,7 @@ string_t* string_split(const string_t string, char separator, size_t* result_siz
   string_t current = malloc(sizeof(char) * (string_length + 1));
   string_t* result = NULL;
   if (current == NULL) {
+    perror("Error (string_split)");
     exit(EXIT_FAILURE);
   }
   while (index_string < string_length) {
@@ -157,6 +159,7 @@ string_t* string_split(const string_t string, char separator, size_t* result_siz
       current[index_current] = '\0';
       result = realloc(result, sizeof(string_t) * (index_result + 1));
       if (result == NULL) {
+        perror("Error (string_split)");
         exit(EXIT_FAILURE);
       }
       result[index_result] = string_copy(current);
@@ -168,10 +171,10 @@ string_t* string_split(const string_t string, char separator, size_t* result_siz
     }
     index_string++;
   }
-
   current[index_current] = '\0';
   result = realloc(result, sizeof(string_t) * (index_result + 1));
   if (result == NULL) {
+    perror("Error (string_split)");
     exit(EXIT_FAILURE);
   }
   result[index_result] = string_copy(current);
@@ -188,6 +191,7 @@ string_t string_join(string_t* array, const char separator, size_t array_length)
   size_t string_length = total_length + (array_length - 1);
   string_t string = malloc(sizeof(char) * (string_length + 1));
   if (string == NULL) {
+    perror("Error (string_join)");
     exit(EXIT_FAILURE);
   }
   size_t current_index = 0;
@@ -214,6 +218,7 @@ string_t string_concatenate(string_t string1, string_t string2) {
   size_t result_length = string1_length + string2_length;
   string_t result = malloc(sizeof(char) * (result_length + 1));
   if (result == NULL) {
+    perror("Error (string_concatenate)");
     exit(EXIT_FAILURE);
   }
   size_t index_string1 = 0;
@@ -293,6 +298,7 @@ string_t string_get_formatted_number(const long long number, string_t separator)
   size_t formatted_length = number_string_length + (number_string_length - 1) / 3;
   string_t result = malloc(sizeof(char) * (formatted_length + 1));
   if (result == NULL) {
+    perror("Error (string_get_formatted_number)");
     exit(EXIT_FAILURE);
   }
   size_t count = 0;
@@ -336,6 +342,7 @@ string_t string_get_last_occurence_of_character(const string_t string, char char
   }
   string_t result = malloc(sizeof(char) * (string_length - index_last_occurrence + 1));
   if (result == NULL) {
+    perror("Error (string_get_last_occurence_of_character)");
     exit(EXIT_FAILURE);
   }
   size_t index_result = 0;
diff --git a/lib/string.h b/lib/string.h
index e596c03..afc6efa 100644
--- a/lib/string.h
+++ b/lib/string.h
@@ -1,6 +1,7 @@
 #ifndef __LIBCPROJECT_STRING__
 #define __LIBCPROJECT_STRING__
 
+#include <errno.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/lib/terminal.c b/lib/terminal.c
index 58c3915..2590732 100644
--- a/lib/terminal.c
+++ b/lib/terminal.c
@@ -5,6 +5,7 @@ string_t terminal_input() {
   size_t length = 1;
   string_t string = malloc(length * sizeof(char));
   if (string == NULL) {
+    perror("Error (terminal_input)");
     exit(EXIT_FAILURE);
   }
   *string = '\0';
@@ -12,6 +13,7 @@ string_t terminal_input() {
     length++;
     string = realloc(string, length * sizeof(char));
     if (string == NULL) {
+      perror("Error (terminal_input)");
       exit(EXIT_FAILURE);
     }
     character_append(string, character);
@@ -54,6 +56,8 @@ void terminal_print_string(void* value) {
 
 void terminal_print_stack(struct stack* stack, void (*print_element)(void*)) {
   if (stack == NULL) {
+    errno = EINVAL;
+    perror("Error (terminal_print_stack)");
     exit(EXIT_FAILURE);
   }
   struct stack_node* node_current = stack->first;
@@ -68,6 +72,8 @@ void terminal_print_stack(struct stack* stack, void (*print_element)(void*)) {
 
 void terminal_print_queue(struct queue* queue, void (*print_element)(void*)) {
   if (queue == NULL) {
+    errno = EINVAL;
+    perror("Error (terminal_print_queue)");
     exit(EXIT_FAILURE);
   }
   struct queue_node* node_current = queue->first;
@@ -82,6 +88,8 @@ void terminal_print_queue(struct queue* queue, void (*print_element)(void*)) {
 
 void terminal_print_linked_list(struct linked_list* linked_list, void (*print_element)(void*)) {
   if (linked_list == NULL) {
+    errno = EINVAL;
+    perror("Error (terminal_print_linked_list)");
     exit(EXIT_FAILURE);
   }
   struct linked_list_node* node_current = linked_list->head;
@@ -96,6 +104,8 @@ void terminal_print_linked_list(struct linked_list* linked_list, void (*print_el
 
 void terminal_print_hash_map(struct hash_map* hash_map, void (*print_element)(void*)) {
   if (hash_map == NULL) {
+    errno = EINVAL;
+    perror("Error (terminal_print_hash_map)");
     exit(EXIT_FAILURE);
   }
   printf("{\n");
diff --git a/lib/terminal.h b/lib/terminal.h
index 58da19f..b557bf8 100644
--- a/lib/terminal.h
+++ b/lib/terminal.h
@@ -1,6 +1,7 @@
 #ifndef __LIBCPROJECT_TERMINAL__
 #define __LIBCPROJECT_TERMINAL__
 
+#include <errno.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>