ft_substr

1. 프로토타입

char	*ft_substr(char const *s, unsigned int start, size_t len)

2. 용도

3. 리턴값

4. 코드 구현

#include "libft.h"

char	*ft_substr(char const *s, unsigned int start, size_t len)
{
	char	*ret;
	size_t	t;
	size_t	slen;

	t = 0;
	slen = 0;
	if (s == NULL)
		return (NULL);
	slen = ft_strlen(s);
	if (slen < start)
		return (ft_strdup(""));
	if (start + len > slen)
		len = slen - start;
	ret = (char *)malloc(sizeof(char) * (len + 1));
	if (ret == 0)
		return (NULL);
	while (t < len && start + t < slen)
	{
		ret[t] = s[start + t];
		t++;
	}
	ret[t] = '\0';
	return (ret);
}

5. 코드 설명