diff --git a/Makefile b/Makefile
index 4d40023..cce1e77 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ CC 		:= gcc
 LD      := $(CC)
 LDFLAGS :=
 CFLAGS  := $(shell cat compile_flags.txt | sed -z "s/\n/ /g")
-SRC     := $(wildcard src/*.c)
+SRC     := $(wildcard src/*.c lib/**/*.c)
 OBJ_DIR := build
 OBJ     := $(addprefix $(OBJ_DIR)/, $(patsubst %.c,%.o,$(SRC)))
 DIR 	:= .
diff --git a/compile_flags.txt b/compile_flags.txt
index 6cabb19..8b67f31 100644
--- a/compile_flags.txt
+++ b/compile_flags.txt
@@ -1,6 +1,9 @@
 -includeinc/main.h
+-includelib/libft/libft.h
+-includelib/ft_printf/ft_printf.h
 -Wall
 -Wextra
 -std=c23
 -iquoteinc
+-iquotelib
 -g
diff --git a/inc/main.h b/inc/main.h
index f7bf511..a65b80d 100644
--- a/inc/main.h
+++ b/inc/main.h
@@ -1,11 +1,15 @@
 #pragma once
 
-typedef struct flags {
-	bool l;
-	bool a;
-	bool R;
-	bool r;
-	bool t;
+#include <inttypes.h>
+
+typedef struct {
+        i64 l;
+        i64 a;
+        i64 R;
+        i64 r;
+        i64 t;
+        int error[2];
 } flags_t;
 
-flags_t get_flags(char **argv);
+flags_t *get_flags(char **argv);
+void display_flags(flags_t flags);
diff --git a/lib/ft_printf b/lib/ft_printf
new file mode 160000
index 0000000..b7b7d5a
--- /dev/null
+++ b/lib/ft_printf
@@ -0,0 +1 @@
+Subproject commit b7b7d5aa04fea13f5da4e4ffb00beb4f5724e3cd
diff --git a/lib/libft b/lib/libft
new file mode 160000
index 0000000..a020fd7
--- /dev/null
+++ b/lib/libft
@@ -0,0 +1 @@
+Subproject commit a020fd795c3dc0a34a59d2906908202cde3d3ccf
diff --git a/src/flags.c b/src/flags.c
index 7454832..f589ac1 100644
--- a/src/flags.c
+++ b/src/flags.c
@@ -1,6 +1,34 @@
-flags_t get_flags(char **argv) {
+flags_t *get_flags(char **argv) {
+    flags_t *flags = ft_calloc(1, sizeof(flags_t));
+    if (flags == nullptr)
+        return nullptr;
+    flags->t = 0;
+    flags->error[0] = -1;
 
-    flags_t flags = {false, false, false, false, false};
+    for (int i = 1; argv[i] != NULL; i++)
+        if (argv[i][0] == '-')
+            for (int j = 1; argv[i][j] != '\0'; j++) {
+                if (argv[i][j] == 'l')
+                    flags->l = 1;
+                else if (argv[i][j] == 'a')
+                    flags->a = 1;
+                else if (argv[i][j] == 'R')
+                    flags->R = 1;
+                else if (argv[i][j] == 'r')
+                    flags->r = 1;
+                else if (argv[i][j] == 't')
+                    flags->t = 1;
+                else {
+                    flags->error[0] = i;
+                    flags->error[1] = j;
+                    return flags;
+                }
+            }
 
     return flags;
 }
+
+void display_flags(flags_t flags) {
+    ft_printf("l: %d; a: %d; R: %d; r: %d; t: %d\n",
+              flags.l, flags.a, flags.R, flags.r, flags.t);
+}
diff --git a/src/main.c b/src/main.c
index 4722db7..49802aa 100644
--- a/src/main.c
+++ b/src/main.c
@@ -3,6 +3,13 @@ int main(int argc, char **argv) {
     if (argc < 2)
         return 1;
 
-    get_flags(argv);
+    flags_t *flags = get_flags(argv);
+    if (flags->error[0] != -1) {
+        ft_printf_fd(2, "ls: invalid line width: \'%s\'",
+                     argv[flags->error[0]][flags->error[1]]);
+        return 2;
+    }
+    display_flags(*flags);
+
     return 0;
 }