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ft_strnstr.c
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ft_strnstr.c
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/* ************************************************************************** */
/* */
/* ::: :::::::: */
/* ft_strnstr.c :+: :+: :+: */
/* +:+ +:+ +:+ */
/* By: htopa <[email protected]> +#+ +:+ +#+ */
/* +#+#+#+#+#+ +#+ */
/* Created: 2024/04/23 13:42:22 by htopa #+# #+# */
/* Updated: 2024/04/27 14:33:31 by htopa ### ########.fr */
/* */
/* ************************************************************************** */
/* **************************************************************************
LIBRARY
libft
DESCRIPTION
The ft_strnstr() function re-implements the original strnstr() function
which is part of the string library. It locates the first occurrence of
the null-terminated string needle in the string haystack, where not more
than len characters are searched. Characters that appear after a ‘\0’
character are not searched.
RETURN VALUES
If needle is an empty string, haystack is returned; if needle occurs
nowhere in haystack, NULL is returned; otherwise a pointer to the first
character of the first occurrence of needle is returned.
***************************************************************************** */
#include "libft.h"
char *ft_strnstr(const char *haystack, const char *needle, size_t len)
{
size_t i;
size_t j;
i = 0;
j = 0;
if (needle[i] == '\0' || needle == NULL)
return ((char *)haystack);
while (haystack[i] != '\0' && i < len)
{
if (haystack[i] == needle[j])
{
while (haystack[i + j] == needle [j] && i + j < len)
{
if (needle[j + 1] == '\0')
return ((char *)(haystack + i));
j++;
}
j = 0;
}
i++;
}
return (NULL);
}