kdb-cli: add expandKeyName function

...to command.c for resolving bookmarks in keynames.

src/tools/kdb/command.c

@@ -0,0 +1,64 @@
+/**
+ * @file
+ *
+ * @brief Implementation of things used everywhere in the kdb tool
+ *
+ * @copyright BSD License (see LICENSE.md or https://www.libelektra.org)
+ */
+
+#include <command.h>
+
+#include <kdberrors.h>
+#include <string.h>
+
+/**
+ * Expands a keyname if it contains a bookmark. If @name does not contain a bookmark ref a copy of @name is returned.
+ *
+ * @param name the keyname that might contain a bookmark, and where the expanded name should be saved
+ * @param ks keyset that contains information about the bookmarks
+ * @param resolved will be set to true iff a bookmark was resolved successfully
+ *
+ * @return NULL if the bookmark could not be resolved, NULL was passed as @ks or @name
+ * @return string of the full key otherwise, has to be freed after usage
+ */
+char * expandKeyName (KeySet * ks, const char * name, bool * resolved)
+{
+	*resolved = false;
+	if (ks == NULL || name == NULL)
+	{
+		return NULL;
+	}
+	char * ret = NULL;
+	if (name[0] != '+')
+	{
+		ret = elektraMalloc (strlen (name));
+		strcpy (ret, name);
+	}
+	else
+	{
+		int bookmarkEnd = strcspn (name, "/");
+		char * bookmarkName = elektraMalloc (bookmarkEnd);
+		strncpy (bookmarkName, name + 1, bookmarkEnd - 1);
+		bookmarkName[bookmarkEnd - 1] = '\0';
+		char * bookmarkKeyName = elektraMalloc (strlen (CLI_BASE_KEY) + strlen ("/bookmarks/") + strlen (bookmarkName) + 1);
+		strcpy (bookmarkKeyName, CLI_BASE_KEY);
+		strcat (bookmarkKeyName, "/bookmarks/");
+		strcat (bookmarkKeyName, bookmarkName);
+
+		Key * bookmarkKey = ksLookupByName (ks, bookmarkKeyName, 0);
+		elektraFree (bookmarkKeyName);
+		elektraFree (bookmarkName);
+		if (bookmarkKey != NULL)
+		{
+			const char * bookmarkValue = keyString (bookmarkKey);
+			ret = elektraMalloc (strlen (name + bookmarkEnd) + strlen (bookmarkValue));
+			strcpy (ret, bookmarkValue);
+			strcat (ret, name + bookmarkEnd);
+			*resolved = true;
+		}
+
+		keyDel (bookmarkKey);
+		return ret;
+	}
+	return NULL;
+}

src/tools/kdb/command.h

@@ -10,6 +10,7 @@
 #define ELEKTRA_KDB_COMMAND_H
 
 #include <kdb.h>
+#include <stdbool.h>
 
 #define CLI_BASE_KEY "/sw/elektra/kdb/#0/current"
 
@@ -63,6 +64,7 @@
 		sleep (1);                                                                                                                 \
 	}
 
+char * expandKeyName (KeySet * ks, const char * name, bool * resolved);
 
 typedef struct command
 {