add: atoi func

Makefile

@@ -6,7 +6,7 @@ VPATH = src:src/ascii:src/memory:src/string
 BUILD_DIR = build
 
 SRCS =	ft_isalnum.c ft_isalpha.c ft_isascii.c ft_isdigit.c ft_isprint.c \
-		ft_toupper.c ft_tolower.c \
+		ft_toupper.c ft_tolower.c ft_atoi.c \
 		ft_strlen.c ft_strlcpy.c ft_strlcat.c ft_strchr.c ft_strrchr.c \
 		ft_strncmp.c ft_strnstr.c \
 		ft_memset.c ft_memcpy.c ft_memchr.c ft_memmove.c ft_bzero.c \

include/libft.h

@@ -6,7 +6,7 @@
 /*   By: ebabaogl <ebabaogl@student.42kocaeli.co    +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2024/04/19 16:05:11 by ebabaogl          #+#    #+#             */
-/*   Updated: 2024/04/27 23:22:02 by ebabaogl         ###   ########.fr       */
+/*   Updated: 2024/05/01 15:35:19 by ebabaogl         ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -22,6 +22,7 @@ int		ft_isdigit(int c);
 int		ft_isprint(int c);
 int		ft_toupper(int c);
 int		ft_tolower(int c);
+int		ft_atoi(const char *nptr);
 
 size_t	ft_strlen(const char *s);
 size_t	ft_strlcpy(char *dst, const char *src, size_t size);

src/ascii/ft_atoi.c

@@ -0,0 +1,37 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_atoi.c                                          :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: ebabaogl <ebabaogl@student.42kocaeli.co    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2024/05/01 14:48:47 by ebabaogl          #+#    #+#             */
+/*   Updated: 2024/05/01 15:33:49 by ebabaogl         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include <stdlib.h>
+#include <stdio.h>
+
+int	ft_atoi(const char *nptr)
+{
+	int	sign;
+	int	total;
+
+	sign = 1;
+	total = 0;
+	while (*nptr == ' ' || (*nptr >= 9 && *nptr <= 13))
+		nptr++;
+	if (*nptr == '-' || *nptr == '+')
+	{
+		sign = 44 - *nptr;
+		nptr++;
+	}
+	while (*nptr >= '0' && *nptr <= '9')
+	{
+		total *= 10;
+		total += *nptr - '0';
+		nptr++;
+	}
+	return (sign * total);
+}