get_next_line_utils.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   get_next_line_utils.c                              :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: tkirihar <tkirihar@student.42tokyo.jp>     +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2021/12/12 21:49:46 by tkirihar          #+#    #+#             */
/*   Updated: 2021/12/12 21:50:00 by tkirihar         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "get_next_line.h"

size_t	ft_strlen(const char *str)
{
	size_t	len;

	len = 0;
	while (str[len] != '\0')
		len++;
	return (len);
}

char	*ft_strjoin(char const *s1, char const *s2)
{
	char	*p;
	size_t	i;
	size_t	j;

	p = (char *)malloc(ft_strlen(s1) + ft_strlen(s2) + 1);
	if (p == NULL)
		return (NULL);
	i = 0;
	while (s1[i] != '\0')
	{
		p[i] = s1[i];
		i++;
	}
	j = 0;
	while (s2[j] != '\0')
	{
		p[i++] = s2[j++];
	}
	p[i] = '\0';
	return (p);
}

char	*ft_strchr(const char *s, int c)
{
	size_t	i;

	i = 0;
	while (s[i] != (char)c && s[i] != '\0')
		i++;
	if (s[i] == (char)c)
		return ((char *)&s[i]);
	else
		return (NULL);
}

char	*ft_substr(char const *s, unsigned int start, size_t len)
{
	char	*p;
	size_t	i;
	size_t	region;

	if (ft_strlen(s) < start)
	{
		p = (char *)malloc(1);
		if (p == NULL)
			return (NULL);
		p[0] = '\0';
		return (p);
	}
	region = ft_strlen(s) - start;
	if (len <= region)
		region = len;
	p = (char *)malloc(region + 1);
	if (p == NULL)
		return (NULL);
	i = 0;
	while (len-- && s[start] != '\0')
		p[i++] = s[start++];
	p[i] = '\0';
	return (p);
}

char	*free_and_return(char *free_variable)
{
	free(free_variable);
	return (NULL);
}