diff --git a/repos/piscine/c04/ex00/ft_strlen.c b/repos/piscine/c04/ex00/ft_strlen.c
new file mode 100644
index 0000000..b97415e
--- /dev/null
+++ b/repos/piscine/c04/ex00/ft_strlen.c
@@ -0,0 +1,33 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_strlen.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: tischmid <marvin@42.fr>                    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/03/27 00:57:16 by tischmid          #+#    #+#             */
+/*   Updated: 2023/03/27 00:58:43 by tischmid         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+int	ft_strlen(char *str)
+{
+	int	i;
+
+	i = 0;
+	while (*str++)
+		++i;
+	return (i);
+}
+
+/* ////
+#include <stdio.h>
+
+int	main(void)
+{
+	char	str[10] = "Hello";
+
+	printf("%d\n", ft_strlen(str));
+	return (0);
+}
+*/ ////