diff --git a/pkg.h b/pkg.h
index ad2551b..b42dc70 100644
--- a/pkg.h
+++ b/pkg.h
@@ -158,5 +158,6 @@ char *pkg_fgetline(char *line, size_t size, FILE *stream);
 pkg_tuple_t *pkg_tuple_add(pkg_tuple_t *parent, const char *key, const char *value);
 char *pkg_tuple_find(pkg_tuple_t *head, const char *key);
 char *pkg_tuple_parse(pkg_tuple_t *vars, const char *value);
+void pkg_tuple_free(pkg_tuple_t *head);
 
 #endif
diff --git a/tuple.c b/tuple.c
new file mode 100644
index 0000000..2ebd20e
--- /dev/null
+++ b/tuple.c
@@ -0,0 +1,118 @@
+/*
+ * tuple.c
+ * management of key->value tuples
+ *
+ * Copyright (c) 2011, 2012 William Pitcock <nenolod@dereferenced.org>.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "pkg.h"
+#include "bsdstubs.h"
+
+pkg_tuple_t *
+pkg_tuple_add(pkg_tuple_t *parent, const char *key, const char *value)
+{
+	pkg_tuple_t *tuple = calloc(sizeof(pkg_tuple_t), 1);
+
+	tuple->key = strdup(key);
+	tuple->value = pkg_tuple_parse(parent, value);
+
+	tuple->next = parent;
+	if (tuple->next != NULL)
+		tuple->next->prev = tuple;
+
+	return tuple;
+}
+
+char *
+pkg_tuple_find(pkg_tuple_t *head, const char *key)
+{
+	pkg_tuple_t *node;
+
+	foreach_list_entry(head, node)
+	{
+		if (!strcasecmp(node->key, key))
+			return node->value;
+	}
+
+	return NULL;
+}
+
+char *
+pkg_tuple_parse(pkg_tuple_t *vars, const char *value)
+{
+	char buf[BUFSIZ];
+	const char *ptr;
+	char *bptr = buf;
+
+	for (ptr = value; *ptr != '\0' && bptr - buf < BUFSIZ; ptr++)
+	{
+		if (*ptr != '$')
+			*bptr++ = *ptr;
+		else if (*(ptr + 1) == '{')
+		{
+			static char varname[BUFSIZ];
+			char *vptr = varname;
+			const char *pptr;
+			char *kv, *parsekv;
+
+			*vptr = '\0';
+
+			for (pptr = ptr + 2; *pptr != '\0'; pptr++)
+			{
+				if (*pptr != '}')
+					*vptr++ = *pptr;
+				else
+				{
+					*vptr = '\0';
+					break;
+				}
+			}
+
+			ptr += (pptr - ptr);
+			kv = pkg_tuple_find(vars, varname);
+
+			if (kv != NULL)
+			{
+				parsekv = pkg_tuple_parse(vars, kv);
+
+				strncpy(bptr, parsekv, BUFSIZ - (bptr - buf));
+				bptr += strlen(parsekv);
+
+				free(parsekv);
+			}
+		}
+	}
+
+	*bptr = '\0';
+
+	return strdup(buf);
+}
+
+void
+pkg_tuple_free(pkg_tuple_t *head)
+{
+	pkg_tuple_t *node, *next;
+
+	foreach_list_entry_safe(head, next, node)
+	{
+		free(node->key);
+		free(node->value);
+		free(node);
+	}
+}