field splitting: implement field splitting

src/postprocess/fieldsplit/fieldsplit.c

@@ -0,0 +1,96 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   fieldsplit.c                                       :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: khais <marvin@42.fr>                       +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2025/04/03 15:48:52 by khais             #+#    #+#             */
+/*   Updated: 2025/04/15 11:51:33 by khais            ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "fieldsplit.h"
+#include "../../buffer/buffer.h"
+#include "../../parser/matchers/blank.h"
+#include <stdlib.h>
+
+static bool	should_delimit(t_worddesc *original, size_t i)
+{
+	if (is_blank(original->word[i]) && original->marker[i] == '$')
+		return (true);
+	return (false);
+}
+
+static void	fieldsplit_delimit(t_buffer *word, t_buffer *marker,
+	t_worddesc *original, t_wordlist **outlist)
+{
+	t_worddesc	*out;
+
+	out = worddesc_create(word->buffer, original->flags, marker->buffer);
+	(*outlist) = wordlist_push(*outlist, out);
+	free(word);
+	free(marker);
+}
+
+static t_wordlist	*minishell_fieldsplit(t_worddesc *original,
+	t_wordlist **outlist)
+{
+	size_t		i;
+	t_buffer	*word;
+	t_buffer	*marker;
+
+	i = 0;
+	word = ft_buffer_new();
+	marker = ft_buffer_new();
+	while (original->word[i] != '\0')
+	{
+		if (should_delimit(original, i))
+		{
+			fieldsplit_delimit(word, marker, original, outlist);
+			word = ft_buffer_new();
+			marker = ft_buffer_new();
+			while (should_delimit(original, i))
+				i++;
+		}
+		else
+		{
+			word = ft_buffer_pushchar(word, original->word[i]);
+			marker = ft_buffer_pushchar(marker, original->marker[i++]);
+		}
+	}
+	fieldsplit_delimit(word, marker, original, outlist);
+	return (*outlist);
+}
+
+static t_wordlist	*wordlist_fieldsplit(t_wordlist **original)
+{
+	t_worddesc	*current;
+	t_wordlist	*out;
+
+	if (original == NULL || *original == NULL)
+		return (NULL);
+	out = NULL;
+	current = wordlist_pop(original);
+	while (current != NULL)
+	{
+		if (minishell_fieldsplit(current, &out) == NULL)
+		{
+			wordlist_destroy(out);
+			return (NULL);
+		}
+		worddesc_destroy(current);
+		current = wordlist_pop(original);
+	}
+	(*original) = out;
+	return (*original);
+}
+
+t_simple_cmd	*simple_cmd_fieldsplit(t_simple_cmd *cmd)
+{
+	if (cmd == NULL)
+		return (NULL);
+	if (wordlist_fieldsplit(&cmd->words) == NULL)
+		return (NULL);
+	return (cmd);
+}