diff --git a/Makefile b/Makefile
index ad46b57..fd1a337 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@
 #    By: kcolin <marvin@42.fr>                      +#+  +:+       +#+         #
 #                                                 +#+#+#+#+#+   +#+            #
 #    Created: 2024/10/14 13:43:59 by kcolin            #+#    #+#              #
-#    Updated: 2024/10/18 11:33:48 by kcolin           ###   ########.fr        #
+#    Updated: 2024/10/18 12:11:14 by kcolin           ###   ########.fr        #
 #                                                                              #
 # **************************************************************************** #
 
@@ -40,7 +40,8 @@ SOURCES = ft_isalpha.c \
 	ft_strtrim.c \
 	ft_split.c \
 	ft_itoa.c \
-	ft_strmapi.c
+	ft_strmapi.c \
+	ft_striteri.c
 OBJECTS = $(SOURCES:.c=.o)
 CC = gcc
 
diff --git a/ft_striteri.c b/ft_striteri.c
new file mode 100644
index 0000000..f5ddb9c
--- /dev/null
+++ b/ft_striteri.c
@@ -0,0 +1,58 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_striteri.c                                      :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: kcolin <marvin@42.fr>                      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2024/10/18 12:04:53 by kcolin            #+#    #+#             */
+/*   Updated: 2024/10/18 12:10:29 by kcolin           ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+void	ft_striteri(char *s, void (*f)(unsigned int, char*))
+{
+	unsigned int	i;
+
+	i = 0;
+	while (s[i] != '\0')
+	{
+		(*f)(i, s + i);
+		i++;
+	}
+}
+
+/*
+#include "libft.h"
+#include <stdio.h>
+
+void	upcase_some_letters(unsigned int i, char *c)
+{
+	if (i % 2 == 0)
+		*c = ft_toupper(*c);
+	else
+		*c = ft_tolower(*c);
+}
+
+
+int	main(int argc, char **argv)
+{
+	if (argc > 1)
+	{
+		int	i = 1;
+
+		while (i < argc)
+		{
+			ft_striteri(argv[i], &upcase_some_letters);
+			printf("%d\t'%s'\n", i, argv[i]);
+			i++;
+		}
+		return (0);
+	}
+	else
+	{
+		printf("Usage: %s <text...>\n", argv[0]);
+		return (1);
+	}
+}
+*/
diff --git a/libft.h b/libft.h
index 0421dd6..0e096b5 100644
--- a/libft.h
+++ b/libft.h
@@ -55,5 +55,6 @@ char	**ft_split(char const *s, char c);
 char	*ft_itoa(int n);
 
 char	*ft_strmapi(char const *s, char (*f)(unsigned int, char));
+void	ft_striteri(char *s, void (*f)(unsigned int, char*));
 
 #endif