lib/command_match.h

   1 /*
   2  * Input matching routines for CLI backend.
   3  *
   4  * --
   5  * Copyright (C) 2016 Cumulus Networks, Inc.
   6  *
   7  * This file is part of GNU Zebra.
   8  *
   9  * GNU Zebra is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License as published by the
  11  * Free Software Foundation; either version 2, or (at your option) any
  12  * later version.
  13  *
  14  * GNU Zebra is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; see the file COPYING; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #ifndef _ZEBRA_COMMAND_MATCH_H
  25 #define _ZEBRA_COMMAND_MATCH_H
  26
  27 #include "graph.h"
  28 #include "linklist.h"
  29 #include "command.h"
  30
  31 /* These definitions exist in command.c in the current engine but should be
  32  * relocated here in the new engine
  33  */
  34 enum filter_type { FILTER_RELAXED, FILTER_STRICT };
  35
  36 /* matcher result value */
  37 enum matcher_rv {
  38         MATCHER_NO_MATCH,
  39         MATCHER_INCOMPLETE,
  40         MATCHER_AMBIGUOUS,
  41         MATCHER_OK,
  42 };
  43
  44 /* completion match types */
  45 enum match_type {
  46         trivial_match, // the input is null
  47         no_match,      // the input does not match
  48         partly_match,  // the input matches but is incomplete
  49         exact_match    // the input matches and is complete
  50 };
  51
  52 /* Defines which matcher_rv values constitute an error. Should be used with
  53  * matcher_rv return values to do basic error checking.
  54  */
  55 #define MATCHER_ERROR(matcher_rv)                                              \
  56         ((matcher_rv) == MATCHER_INCOMPLETE                                    \
  57          || (matcher_rv) == MATCHER_NO_MATCH                                   \
  58          || (matcher_rv) == MATCHER_AMBIGUOUS)
  59
  60 /**
  61  * Attempt to find an exact command match for a line of user input.
  62  *
  63  * @param[in] cmdgraph command graph to match against
  64  * @param[in] vline vectorized input string
  65  * @param[out] argv pointer to argument list if successful match, NULL
  66  * otherwise. The elements of this list are pointers to struct cmd_token
  67  * and represent the sequence of tokens matched by the inpu. The ->arg
  68  * field of each token points to a copy of the input matched on it. These
  69  * may be safely deleted or modified.
  70  * @param[out] element pointer to matched cmd_element if successful match,
  71  * or NULL when MATCHER_ERROR(rv) is true. The cmd_element may *not* be
  72  * safely deleted or modified; it is the instance initialized on startup.
  73  * @return matcher status
  74  */
  75 enum matcher_rv command_match(struct graph *cmdgraph, vector vline,
  76                               struct list **argv,
  77                               const struct cmd_element **element);
  78
  79 /**
  80  * Compiles possible completions for a given line of user input.
  81  *
  82  * @param[in] start the start node of the DFA to match against
  83  * @param[in] vline vectorized input string
  84  * @param[out] completions pointer to list of cmd_token representing
  85  * acceptable next inputs, or NULL when MATCHER_ERROR(rv) is true.
  86  * The elements of this list are pointers to struct cmd_token and take on a
  87  * variety of forms depending on the passed vline. If the last element in vline
  88  * is NULL, all previous elements are considered to be complete words (the case
  89  * when a space is the last token of the line) and completions are generated
  90  * based on what could follow that input. If the last element in vline is not
  91  * NULL and each sequential element matches the corresponding tokens of one or
  92  * more commands exactly (e.g. 'encapv4' and not 'en') the same result is
  93  * generated. If the last element is not NULL and the best possible match is a
  94  * partial match, then the result generated will be all possible continuations
  95  * of that element (e.g. 'encapv4', 'encapv6', etc for input 'en').
  96  * @return matcher status
  97  */
  98 enum matcher_rv command_complete(struct graph *cmdgraph, vector vline,
  99                                  struct list **completions);
 100
 101 #endif /* _ZEBRA_COMMAND_MATCH_H */