ft_strnstr: initial implementation

Makefile

@@ -6,7 +6,7 @@
 #    By: kcolin <marvin@42.fr>                      +#+  +:+       +#+         #
 #                                                 +#+#+#+#+#+   +#+            #
 #    Created: 2024/10/14 13:43:59 by kcolin            #+#    #+#              #
-#    Updated: 2024/10/16 15:22:08 by kcolin           ###   ########.fr        #
+#    Updated: 2024/10/16 15:38:09 by kcolin           ###   ########.fr        #
 #                                                                              #
 # **************************************************************************** #
 
@@ -30,7 +30,8 @@ SOURCES = ft_isalpha.c \
 	ft_strrchr.c \
 	ft_strncmp.c \
 	ft_memchr.c \
-	ft_memcmp.c
+	ft_memcmp.c \
+	ft_strnstr.c
 OBJECTS = $(SOURCES:.c=.o)
 CC = gcc
 

ft_strnstr.c

@@ -0,0 +1,61 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_strnstr.c                                       :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: kcolin <marvin@42.fr>                      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2024/10/16 15:38:24 by kcolin            #+#    #+#             */
+/*   Updated: 2024/10/16 15:58:22 by kcolin           ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+char	*ft_strnstr(const char *big, const char *little, size_t len)
+{
+	size_t	i;
+	size_t	j;
+	int		found;
+
+	if (*little == '\0')
+		return ((char *)big);
+	i = 0;
+	while (big[i] != '\0' && i < len)
+	{
+		j = 0;
+		found = 1;
+		while (little[j] != '\0' && i + j < len)
+		{
+			if (little[j] != big[i + j])
+			{
+				found = 0;
+				break ;
+			}
+			j++;
+		}
+		if (found == 1 && little[j] == '\0')
+			return ((char *)big + i);
+		i++;
+	}
+	return (NULL);
+}
+
+/*
+#include <stdio.h>
+#include <bsd/string.h>
+
+int	main(int argc, char **argv)
+{
+	size_t	cmp_len;
+
+	cmp_len = 40;
+	if (argc > 2)
+	{
+		printf("mine: %s\nlib:  %s\n",
+			ft_strnstr(argv[1], argv[2], cmp_len),
+			strnstr(argv[1], argv[2], cmp_len));
+	}
+	return (0);
+}
+*/

libft.h

@@ -40,4 +40,6 @@ int		ft_strncmp(const char *s1, const char *s2, size_t n);
 void	*ft_memchr(const void *s, int c, size_t n);
 int		ft_memcmp(const void *s1, const void *s2, size_t n);
 
+char	*ft_strnstr(const char *big, const char *little, size_t len);
+
 #endif