ft_split

Subject

Assignment name  : ft_split
Expected files   : ft_split.c
Allowed functions: malloc
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Write a function that takes a string, splits it into words, and returns them as
a NULL-terminated array of strings.

A "word" is defined as a part of a string delimited either by spaces/tabs/new
lines, or by the start/end of the string.

Your function must be declared as follows:

char    **ft_split(char *str);

Commented solution

ft_split

ft_split.c

#include "stdlib.h"
#include "unistd.h"

int	count_words(char *str)
{
	int	i;
	int	count;

	i = 0;
	count = 0;
	while (str[i] != '\0')
	{
		while (str[i] == ' ' || str[i] == '\t' || str[i] == '\n')
			i++;
		if (str[i] != '\0')
			count++;
		while (str[i] != '\0' && str[i] != ' ' && str[i] != '\t'
			&& str[i] != '\n')
			i++;
	}
	return (count);
}

void	copy_words(char *tab, char *str, int start, int end)
{
	int	j;

	j = 0;
	while (start < end)
		tab[j++] = str[start++];
	tab[j] = '\0';
}

int	find_next_word(char *str, int *start, int *end)
{
	int	i;

	i = *end;
	while (str[i] != '\0' && (str[i] == ' ' || str[i] == '\t'
			|| str[i] == '\n'))
		i++;
	*start = i;
	while (str[i] != '\0' && str[i] != ' ' && str[i] != '\t' && str[i] != '\n')
		i++;
	*end = i;
	return (*start < *end);
}

int	ft_fill_words(char **tab, char *str)
{
	int	i;
	int	word;
	int	start;
	int	end;

	i = 0;
	word = 0;
	start = 0;
	end = 0;
	while (find_next_word(str, &start, &end))
	{
		tab[word] = malloc((end - start + 1) * sizeof(char));
		if (tab[word] == NULL)
		{
			i = 0;
			while (i < word)
				free(tab[i++]);
			free(tab);
			return (0);
		}
		copy_words(tab[word], str, start, end);
		word++;
	}
	tab[word] = NULL;
	return (1);
}

char	**ft_split(char *str)
{
	char	**out;
	int		size;

	size = count_words(str);
	out = malloc((sizeof(char *) * (size + 1)));
	if (!out)
		return (NULL);
	if (!ft_fill_words(out, str))
	{
		free(out);
		return (NULL);
	}
	return (out);
}