Implemented some ast handlings...

ast lists, and_or, redirection and builtins

src/utils/ast/ast_redir.c

@@ -0,0 +1,36 @@
+#include "utils/ast/ast_redir.h"
+#include <stdlib.h>
+
+bool ast_is_redir(struct ast *node)
+{
+    return node != NULL && node->type == AST_REDIR;
+}
+
+struct ast_redir *ast_get_redir(struct ast *node)
+{
+    if (ast_is_redir(node))
+        return (struct ast_redir *)node->data;
+    return NULL;
+}
+
+struct ast *ast_create_redir(struct ast *child, char *filename, int io_number, enum ast_redir_type type)
+{
+    struct ast_redir *redir = malloc(sizeof(struct ast_redir));
+    if (!redir)
+        return NULL;
+    redir->child = child;
+    redir->filename = filename; // Takes ownership? Usually yes in simple ASTs, or dup. Let's assume pointer copy for now, but user must manage memory.
+    redir->io_number = io_number;
+    redir->type = type;
+
+    return ast_create(AST_REDIR, redir);
+}
+
+void ast_free_redir(struct ast_redir *redir)
+{
+    if (!redir)
+        return;
+    ast_free(&redir->child);
+    free(redir->filename);
+    free(redir);
+}