input validation

libft/ft_strchr.c

@@ -0,0 +1,29 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_strchr.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: dgaillet <dgaillet@student.42.fr>          +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2025/11/05 17:24:37 by dgaillet          #+#    #+#             */
+/*   Updated: 2025/11/12 13:54:20 by dgaillet         ###   ########lyon.fr   */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+char	*ft_strchr(const char *s, int c)
+{
+	int	i;
+
+	i = 0;
+	while (s[i])
+	{
+		if ((unsigned char) s[i] == (unsigned char) c)
+			return ((char *) s + i);
+		i++;
+	}
+	if ((unsigned char) s[i] == (unsigned char) c)
+		return ((char *) s + i);
+	return (NULL);
+}