save commit

minishell-codex/src/parser/lexer.c

@@ -0,0 +1,131 @@
+#include "minishell.h"
+
+static t_token *token_new(t_tokentype type, const char *text, size_t len)
+{
+	t_token *t = (t_token *)calloc(1, sizeof(t_token));
+	if (!t)
+		return NULL;
+	t->type = type;
+	if (text)
+		t->text = ms_strndup(text, len);
+	return t;
+}
+
+static void token_add(t_token **head, t_token *new)
+{
+	t_token *cur;
+	if (!new)
+		return;
+	if (!*head)
+	{
+		*head = new;
+		return;
+	}
+	cur = *head;
+	while (cur->next)
+		cur = cur->next;
+	cur->next = new;
+}
+
+void free_tokens(t_token *toks)
+{
+	t_token *n;
+	while (toks)
+	{
+		n = toks->next;
+		free(toks->text);
+		free(toks);
+		toks = n;
+	}
+}
+
+static int is_meta(char c)
+{
+	return (c == '|' || c == '<' || c == '>');
+}
+
+static int read_word(const char *line, size_t *i, t_token **out)
+{
+	size_t start = *i;
+	int in_single = 0;
+	int in_double = 0;
+
+	while (line[*i])
+	{
+		if (line[*i] == '\'' && !in_double)
+			in_single = !in_single;
+		else if (line[*i] == '"' && !in_single)
+			in_double = !in_double;
+		else if (!in_single && !in_double)
+		{
+			if (ms_is_space(line[*i]) || is_meta(line[*i]))
+				break;
+		}
+		(*i)++;
+	}
+	if (in_single || in_double)
+		return 1;
+	*out = token_new(TOK_WORD, line + start, *i - start);
+	return 0;
+}
+
+t_token *lex_line(const char *line, int *error)
+{
+	t_token *toks = NULL;
+	size_t i = 0;
+
+	*error = 0;
+	while (line[i])
+	{
+		if (ms_is_space(line[i]))
+		{
+			i++;
+			continue;
+		}
+		if (line[i] == '|')
+		{
+			token_add(&toks, token_new(TOK_PIPE, "|", 1));
+			i++;
+			continue;
+		}
+		if (line[i] == '<')
+		{
+			if (line[i + 1] == '<')
+			{
+				token_add(&toks, token_new(TOK_HEREDOC, "<<", 2));
+				i += 2;
+			}
+			else
+			{
+				token_add(&toks, token_new(TOK_REDIR_IN, "<", 1));
+				i++;
+			}
+			continue;
+		}
+		if (line[i] == '>')
+		{
+			if (line[i + 1] == '>')
+			{
+				token_add(&toks, token_new(TOK_REDIR_APPEND, ">>", 2));
+				i += 2;
+			}
+			else
+			{
+				token_add(&toks, token_new(TOK_REDIR_OUT, ">", 1));
+				i++;
+			}
+			continue;
+		}
+		{
+			t_token *w = NULL;
+			if (read_word(line, &i, &w))
+			{
+				*error = 1;
+				free_tokens(toks);
+				return NULL;
+			}
+			token_add(&toks, w);
+		}
+	}
+	return toks;
+}