1 files changed, 89 insertions, 0 deletions
diff --git a/lib/command_match.h b/lib/command_match.h
new file mode 100644
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--- /dev/null
+++ b/lib/command_match.h
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Input matching routines for CLI backend.
+ *
+ * --
+ * Copyright (C) 2016 Cumulus Networks, Inc.
+ */
+
+#ifndef _ZEBRA_COMMAND_MATCH_H
+#define _ZEBRA_COMMAND_MATCH_H
+
+#include "graph.h"
+#include "linklist.h"
+#include "command.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* matcher result value */
+enum matcher_rv {
+	MATCHER_NO_MATCH,
+	MATCHER_INCOMPLETE,
+	MATCHER_AMBIGUOUS,
+	MATCHER_OK,
+};
+
+/* completion match types */
+enum match_type {
+	trivial_match, // the input is null
+	no_match,      // the input does not match
+	partly_match,  // the input matches but is incomplete
+	exact_match    // the input matches and is complete
+};
+
+/* Defines which matcher_rv values constitute an error. Should be used with
+ * matcher_rv return values to do basic error checking.
+ */
+#define MATCHER_ERROR(matcher_rv)                                              \
+	((matcher_rv) == MATCHER_INCOMPLETE                                    \
+	 || (matcher_rv) == MATCHER_NO_MATCH                                   \
+	 || (matcher_rv) == MATCHER_AMBIGUOUS)
+
+/**
+ * Attempt to find an exact command match for a line of user input.
+ *
+ * @param[in] cmdgraph command graph to match against
+ * @param[in] vline vectorized input string
+ * @param[out] argv pointer to argument list if successful match, NULL
+ * otherwise. The elements of this list are pointers to struct cmd_token
+ * and represent the sequence of tokens matched by the input. The ->arg
+ * field of each token points to a copy of the input matched on it. These
+ * may be safely deleted or modified.
+ * @param[out] element pointer to matched cmd_element if successful match,
+ * or NULL when MATCHER_ERROR(rv) is true. The cmd_element may *not* be
+ * safely deleted or modified; it is the instance initialized on startup.
+ * @return matcher status
+ */
+enum matcher_rv command_match(struct graph *cmdgraph, vector vline,
+			      struct list **argv,
+			      const struct cmd_element **element);
+
+/**
+ * Compiles possible completions for a given line of user input.
+ *
+ * @param[in] start the start node of the DFA to match against
+ * @param[in] vline vectorized input string
+ * @param[out] completions pointer to list of cmd_token representing
+ * acceptable next inputs, or NULL when MATCHER_ERROR(rv) is true.
+ * The elements of this list are pointers to struct cmd_token and take on a
+ * variety of forms depending on the passed vline. If the last element in vline
+ * is NULL, all previous elements are considered to be complete words (the case
+ * when a space is the last token of the line) and completions are generated
+ * based on what could follow that input. If the last element in vline is not
+ * NULL and each sequential element matches the corresponding tokens of one or
+ * more commands exactly (e.g. 'encapv4' and not 'en') the same result is
+ * generated. If the last element is not NULL and the best possible match is a
+ * partial match, then the result generated will be all possible continuations
+ * of that element (e.g. 'encapv4', 'encapv6', etc for input 'en').
+ * @return matcher status
+ */
+enum matcher_rv command_complete(struct graph *cmdgraph, vector vline,
+				 struct list **completions);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _ZEBRA_COMMAND_MATCH_H */