dabba/help.c

   1 /**
   2  * \file help.c
   3  * \author written by Emmanuel Roullit emmanuel.roullit@gmail.com (c) 2012
   4  * \date 2012
   5  */
   6
   7 /* __LICENSE_HEADER_BEGIN__ */
   8
   9 /*
  10  * Copyright (C) 2012   Emmanuel Roullit <emmanuel.roullit@gmail.com>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or (at
  15  * your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  20  * for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License along
  23  * with this program; if not, write to the Free Software Foundation, Inc.,
  24  * 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
  25  *
  26  */
  27
  28 /* __LICENSE_HEADER_END__ */
  29
  30 #include <stdio.h>
  31 #include <string.h>
  32 #include <getopt.h>
  33 #include <assert.h>
  34 #include <libdabba/macros.h>
  35
  36 static const char dabba_usage_string[] = "dabba [--help] <command> [<args>]\n";
  37 static const char dabba_more_info_string[] =
  38     "See 'dabba help <command>' for more info on a specific command.";
  39
  40 struct cmdname_help {
  41         char name[16];
  42         char help[80];
  43 };
  44
  45 void show_usage(const struct option const *opt)
  46 {
  47         assert(opt);
  48
  49         printf("%s", dabba_usage_string);
  50
  51         if (opt != NULL) {
  52                 while (opt->name != NULL) {
  53                         printf("  --%s", opt->name);
  54                         if (opt->has_arg == required_argument)
  55                                 printf(" <arg>\n");
  56                         else if (opt->has_arg == optional_argument)
  57                                 printf(" [arg]\n");
  58                         else
  59                                 printf("\n");
  60                         opt++;
  61                 }
  62         }
  63 }
  64
  65 static inline void mput_char(char c, uint32_t num)
  66 {
  67         while (num--)
  68                 putchar(c);
  69 }
  70
  71 void help_unknown_cmd(const char const *cmd)
  72 {
  73         assert(cmd);
  74         printf("'%s' is not a dabba command. See 'dabba --help'.\n", cmd);
  75 }
  76
  77 static void list_common_cmds_help(void)
  78 {
  79         size_t i, longest = 0;
  80
  81         static struct cmdname_help common_cmds[] = {
  82                 {"interface", "perform an interface related command"},
  83                 {"capture", "capture live traffic from an interface"}
  84         };
  85
  86         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
  87                 if (longest < strlen(common_cmds[i].name))
  88                         longest = strlen(common_cmds[i].name);
  89         }
  90
  91         printf("The most commonly used dabba commands are:\n");
  92         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
  93                 printf("   %s   ", common_cmds[i].name);
  94                 mput_char(' ', longest - strlen(common_cmds[i].name));
  95                 printf("%s\n", common_cmds[i].help);
  96         }
  97 }
  98
  99 /**
 100  * \brief Print help
 101  * \param[in]           argc            Argument counter
 102  * \param[in]           argv            Argument vector
 103  * \return Always returns 0.
 104  *
 105  * This function prints the basic dabba usage help message.
 106  * Furthermore, it lists all available command.
 107  */
 108
 109 int cmd_help(int argc, const char **argv)
 110 {
 111         /* cast here to avoid argc and argv unused GCC warning */
 112         (void)argc;
 113         (void)argv;
 114
 115         printf("usage: %s\n\n", dabba_usage_string);
 116         list_common_cmds_help();
 117         printf("\n%s\n", dabba_more_info_string);
 118
 119         return 0;
 120 }