commit 1d0f0b1901ab4556e229ee4fcda06724189c711d
Author: Camille Chauvet <cchauvet@1A5.42angouleme.fr>
Date:   Tue Sep 27 16:29:23 2022 +0200

    m

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..2f03087
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,64 @@
+# **************************************************************************** #
+#                                                                              #
+#                                                         :::      ::::::::    #
+#    Makefile                                           :+:      :+:    :+:    #
+#                                                     +:+ +:+         +:+      #
+#    By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+         #
+#                                                 +#+#+#+#+#+   +#+            #
+#    Created: 2022/09/27 08:39:27 by cchauvet          #+#    #+#              #
+#    Updated: 2022/09/27 16:08:49 by cchauvet         ###   ########.fr        #
+#                                                                              #
+# **************************************************************************** #
+
+SRCS = ft_isalpha.c \
+	   ft_isdigit.c \
+	   ft_isalnum.c \
+	   ft_isascii.c \
+	   ft_isprint.c \
+	   ft_strlen.c \
+	   ft_memset.c \
+	   ft_bzero.c \
+	   ft_toupper.c \
+	   ft_tolower.c \
+	   ft_strchr.c \
+	   ft_strrchr.c \
+	   ft_strncmp.c \
+	   ft_memcpy.c \
+	   ft_memmove.c \
+	   ft_memchr.c \
+	   ft_memcmp.c \
+	   ft_strdup.c \
+	   ft_calloc.c
+
+COMMENT = ft_strlcpy.c \
+	   ft_strlcat.c \
+	   ft_strnstr.c \
+	   ft_atoi.c \
+	   ft_strdup.c
+
+OBJS = ${SRCS:.c=.o}
+
+NAME = libft
+
+CFLAG = -Wall -Werror -Wextra
+
+all:
+	gcc -c ${CFLAG} ${SRCS}
+	ar rc ${NAME}.a ${OBJS}
+
+clean:
+	rm -f ${OBJS}
+
+fclean:
+	rm -f ${OBJS}
+	rm -f ${NAME}.a
+
+re:
+	rm -f ${OBJS}
+	rm -f ${NAME}.a
+	gcc -c ${CFLAG} ${SRCS}
+	ar rc ${NAME}.a ${OBJS}
+
+so:
+	$(CC) -nostartfiles -fPIC $(CFLAGS) $(SRC)
+	gcc -nostartfiles -shared -o libft.so $(OBJ)
diff --git a/a.out b/a.out
new file mode 100755
index 0000000..4b38cff
Binary files /dev/null and b/a.out differ
diff --git a/ft_atoi.c b/ft_atoi.c
new file mode 100644
index 0000000..bb70a98
--- /dev/null
+++ b/ft_atoi.c
@@ -0,0 +1,36 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_atoi.c                                          :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/27 16:14:34 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 16:22:36 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+int	ft_atoi(const char *nptr)
+{
+	char	*str;
+	int		out;
+	int		sign;
+
+	out = 0;
+	while (*str == " ")
+		str++;
+	sign = 1;
+	if (*str == '-')
+	{
+		sign = -1;
+		str++;
+	}
+	while (ft_isdigit(*str))
+	{
+		out = 10 * out + *str - 48;
+		*str++;
+	}
+	return (out * sign)
+}
diff --git a/ft_bzero.c b/ft_bzero.c
new file mode 100644
index 0000000..7947aeb
--- /dev/null
+++ b/ft_bzero.c
@@ -0,0 +1,18 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_bzero.c                                         :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/27 09:40:13 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 09:41:02 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+void	ft_bzero(void *s, size_t n)
+{
+	ft_memset(s, 0, n);
+}
diff --git a/ft_calloc.c b/ft_calloc.c
new file mode 100644
index 0000000..3f59756
--- /dev/null
+++ b/ft_calloc.c
@@ -0,0 +1,24 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_calloc.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/27 16:09:01 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 16:12:30 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+void	*calloc(size_t nmemb, size_t size)
+{
+	char	*tab;
+
+	if (nmemb * size == 0)
+		return (NULL);
+	tab = malloc(nmemb * size);
+	ft_bzero(tab, nmemb * size);
+	return (tab);
+}
diff --git a/ft_isalnum.c b/ft_isalnum.c
new file mode 100644
index 0000000..d0fbab4
--- /dev/null
+++ b/ft_isalnum.c
@@ -0,0 +1,22 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_isalnum.c                                       :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/26 11:15:04 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 11:32:40 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+int	ft_isalnum(int c)
+{
+	if ((('9' >= c && c >= '0')
+			|| ('z' >= c && c >= 'a')
+			|| ('Z' >= c && c >= 'A')))
+		return (1);
+	return (0);
+}
diff --git a/ft_isalpha.c b/ft_isalpha.c
new file mode 100644
index 0000000..9573931
--- /dev/null
+++ b/ft_isalpha.c
@@ -0,0 +1,20 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_isalpha.c                                       :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/26 11:15:04 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 11:04:58 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+int	ft_isalpha(int c)
+{
+	if (('z' >= c && c >= 'a') || ('Z' >= c && c >= 'A'))
+		return (1);
+	return (0);
+}
diff --git a/ft_isascii.c b/ft_isascii.c
new file mode 100644
index 0000000..5706106
--- /dev/null
+++ b/ft_isascii.c
@@ -0,0 +1,18 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_isascii.c                                       :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/26 11:57:55 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/26 13:33:50 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+int	ft_isascii(int c)
+{
+	if (c >= 0 && 127 >= c)
+		return (1);
+	return (0);
+}
diff --git a/ft_isdigit.c b/ft_isdigit.c
new file mode 100644
index 0000000..0db99f6
--- /dev/null
+++ b/ft_isdigit.c
@@ -0,0 +1,20 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_isdigit.c                                       :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/26 11:15:04 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 11:09:19 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+int	ft_isdigit(int c)
+{
+	if ('9' >= c && c >= '0')
+		return (1);
+	return (0);
+}
diff --git a/ft_isprint.c b/ft_isprint.c
new file mode 100644
index 0000000..d16a74e
--- /dev/null
+++ b/ft_isprint.c
@@ -0,0 +1,18 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_isprint.c                                       :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/26 11:52:31 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 15:46:02 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+int	ft_isprint(int c)
+{
+	return (32 <= c && c <= 127);
+}
diff --git a/ft_memchr.c b/ft_memchr.c
new file mode 100644
index 0000000..28f3775
--- /dev/null
+++ b/ft_memchr.c
@@ -0,0 +1,31 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_memchr.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/27 13:40:09 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 13:59:03 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+void	*ft_memchr(const void *s, int c, size_t n)
+{
+	unsigned char	*tab;
+	size_t			i;
+	unsigned char	tofind;
+
+	tab = (unsigned char *) s;
+	tofind = (unsigned char) c;
+	i = 0;
+	while (i < n)
+	{
+		if (tab[i] == tofind)
+			return (tab + i);
+		i++;
+	}
+	return (NULL);
+}
diff --git a/ft_memcmp.c b/ft_memcmp.c
new file mode 100644
index 0000000..d9460f3
--- /dev/null
+++ b/ft_memcmp.c
@@ -0,0 +1,29 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_memcmp.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/27 14:15:37 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 15:10:56 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+int	ft_memcmp(const void *s1, const void *s2, size_t n)
+{
+	unsigned char	*str1;
+	unsigned char	*str2;
+	size_t			i;
+
+	if (n == 0)
+		return (0);
+	str1 = (unsigned char *) s1;
+	str2 = (unsigned char *) s2;
+	i = 0;
+	while (str1[i] == str2[i] && i < n - 1)
+		i++;
+	return (str1[i] - str2[i]);
+}
diff --git a/ft_memcpy.c b/ft_memcpy.c
new file mode 100644
index 0000000..1467ba9
--- /dev/null
+++ b/ft_memcpy.c
@@ -0,0 +1,32 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_memcpy.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/27 09:42:11 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 15:07:20 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+void	*ft_memcpy(void *dest, const void *src, size_t n)
+{
+	char	*tab1;
+	char	*tab2;
+	size_t	i;
+
+	if (dest == NULL || src == NULL)
+		return (NULL);
+	tab1 = dest;
+	tab2 = (void *) src;
+	i = 0;
+	while (i < n)
+	{
+			tab1[i] = tab2[i];
+			i++;
+	}
+	return (tab1);
+}
diff --git a/ft_memmove.c b/ft_memmove.c
new file mode 100644
index 0000000..309c6b6
--- /dev/null
+++ b/ft_memmove.c
@@ -0,0 +1,35 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_memmove.c                                       :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/27 11:44:12 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 14:14:24 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+void	*ft_memmove(void *dest, const void *src, size_t n)
+{
+	size_t	i;
+	char	*tab1;
+	char	*tab2;
+
+	tab1 = dest;
+	tab2 = (void *) src;
+	if (tab1 < tab2)
+		ft_memcpy(dest, src, n);
+	else
+	{
+		i = n;
+		while (0 < i)
+		{
+			i--;
+			tab1[i] = tab2[i];
+		}
+	}
+	return (dest);
+}
diff --git a/ft_memset.c b/ft_memset.c
new file mode 100644
index 0000000..63e27dc
--- /dev/null
+++ b/ft_memset.c
@@ -0,0 +1,28 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_memset.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/27 09:29:51 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 09:48:23 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+void	*ft_memset(void *s, int c, size_t n)
+{
+	char	*tab;
+	size_t	i;
+
+	tab = s;
+	i = 0;
+	while (i < n)
+	{
+		tab[i] = c;
+		i++;
+	}
+	return (s);
+}
diff --git a/ft_strchr.c b/ft_strchr.c
new file mode 100644
index 0000000..50a6e5f
--- /dev/null
+++ b/ft_strchr.c
@@ -0,0 +1,24 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_strchr.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/26 14:44:15 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 11:30:30 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+char	*strchr(const char *s, int c)
+{
+	while (*s)
+	{
+		if (*s == c)
+			return ((char *) s);
+		s++;
+	}
+	return (NULL);
+}
diff --git a/ft_strdup.c b/ft_strdup.c
new file mode 100644
index 0000000..0f56c0c
--- /dev/null
+++ b/ft_strdup.c
@@ -0,0 +1,31 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_strdup.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/27 16:00:49 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 16:07:00 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+char	*strdup(const char *s)
+{
+	char	*in;
+	char	*out;
+	size_t	i;
+
+	in = (char *) s;
+	out = malloc(sizeof(char) * (ft_strlen(in) + 1));
+	i = 0;
+	while (in[i])
+	{
+		out[i] = in[i];
+		i++;
+	}
+	out[i] = 0;
+	return (out);
+}
diff --git a/ft_strlcpy.c b/ft_strlcpy.c
new file mode 100644
index 0000000..c29d03d
--- /dev/null
+++ b/ft_strlcpy.c
@@ -0,0 +1,29 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_strlcpy.c                                       :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/27 16:24:15 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 16:29:08 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+char	*strlcpy(char *dst, const char *src, size_t size)
+{
+	char	*str;
+	size_t	i;
+
+	i = 0;
+	str = (char *) src;
+	while (str[i + 1] && dst[i + 1] && i < size - 1)
+	{
+		dst[i] = src[i];
+		i++;
+	}
+	dst[i] = 0;
+	return (dst);
+}
diff --git a/ft_strlen.c b/ft_strlen.c
new file mode 100644
index 0000000..9e0d47f
--- /dev/null
+++ b/ft_strlen.c
@@ -0,0 +1,22 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_strlen.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/26 12:03:59 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 09:02:11 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+#include <stddef.h>
+
+size_t	ft_strlen(const char *s)
+{
+	size_t	length;
+
+	length = 0;
+	while (s[length])
+		length++;
+	return (length);
+}
diff --git a/ft_strncmp.c b/ft_strncmp.c
new file mode 100644
index 0000000..dc02068
--- /dev/null
+++ b/ft_strncmp.c
@@ -0,0 +1,23 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_strncmp.c                                       :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/27 08:30:26 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 08:36:25 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+int	strncmp(const char *s1, const char *s2, size_t n)
+{
+	size_t	i;
+
+	i = 0;
+	while (s1[i] == s2[i] && i < n - 1 && s1[i] && s2[i])
+		i++;
+	return (s1[i] - s2[i]);
+}
diff --git a/ft_strrchr.c b/ft_strrchr.c
new file mode 100644
index 0000000..98d30c4
--- /dev/null
+++ b/ft_strrchr.c
@@ -0,0 +1,27 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_strrchr.c                                       :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/27 08:25:33 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 11:29:58 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+char	*strrchr(const char *s, int c)
+{
+	char	*ret;
+
+	ret = NULL;
+	while (*s)
+	{
+		if (*s == (char) c)
+			ret = (char *) s;
+		s++;
+	}
+	return (ret);
+}
diff --git a/ft_strstr.c b/ft_strstr.c
new file mode 100644
index 0000000..dc0fd2c
--- /dev/null
+++ b/ft_strstr.c
@@ -0,0 +1,31 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_strstr.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/26 13:39:33 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/26 15:11:03 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "lib_ft.h"
+
+char	*strstr(const char *haystack, const char *needle)
+{
+	int	i;
+
+	if (!*needle)
+		return (haystack);
+	while (*haystack)
+	{
+		i = 0;
+		while (*(haystack + i) == *(needle + i))
+			i++;
+		if (!*(haystack + i))
+			return (needle);
+		str++;
+	}
+	return (NULL);
+}
diff --git a/ft_tolower.c b/ft_tolower.c
new file mode 100644
index 0000000..642fee9
--- /dev/null
+++ b/ft_tolower.c
@@ -0,0 +1,20 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_tolower.c                                       :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/26 13:25:48 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 11:18:32 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+int	ft_lower(int c)
+{
+	if (c >= 'A' && 'Z' >= c)
+		return (c - 48);
+	return (c);
+}
diff --git a/ft_toupper.c b/ft_toupper.c
new file mode 100644
index 0000000..6fda229
--- /dev/null
+++ b/ft_toupper.c
@@ -0,0 +1,20 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_toupper.c                                       :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/26 12:38:07 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 11:04:06 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+int	ft_toupper(int c)
+{
+	if (c >= 'a' && 'z' >= c)
+		return (c - 48);
+	return (c);
+}
diff --git a/libft.h b/libft.h
new file mode 100644
index 0000000..9ae182c
--- /dev/null
+++ b/libft.h
@@ -0,0 +1,41 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   libft.h                                            :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cchauvet <cchauvet@student.42angoulem      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2022/09/26 14:47:54 by cchauvet          #+#    #+#             */
+/*   Updated: 2022/09/27 16:06:28 by cchauvet         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#ifndef LIBFT_H
+# define LIBFT_H
+# include <stddef.h>
+# include <stdlib.h>
+
+int		ft_isalpha(int c);
+int		ft_isdigit(int c);
+int		ft_isalnum(int c);
+int		ft_isascii(int c);
+int		ft_isprint(int c);
+size_t	ft_strlen(const char *s);
+/* todo */
+void	*ft_memset(void *s, int c, size_t n);
+void	ft_bzero(void *s, size_t n);
+void	*ft_memcpy(void *dest, const void *src, size_t n);
+void	*ft_memmove(void *dest, const void *src, size_t n);
+size_t	ft_strlcpy(char *dst, const char *src, size_t size);
+size_t	ft_strlcat(char *dst, const char *src, size_t size);
+int		ft_toupper(int c);
+int		ft_tolower(int c);
+char	*ft_strchr(const char *s, int c);
+char	*ft_strrchr(const char *s, int c);
+int		ft_strncmp(const char *s1, const char *s2, size_t n);
+void	*ft_memchr(const void *s, int c, size_t n);
+void	*ft_memrchr(const void *s, int c, size_t n);
+char	*ft_strnstr(const char *big, const char *little, size_t len);
+int		ft_atoi(const char *nptr);
+
+#endif