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 <unistd.h>
  33 #include <errno.h>
  34 #include <getopt.h>
  35 #include <assert.h>
  36 #include <libdabba/macros.h>
  37
  38 static const char dabba_usage_string[] =
  39     "dabba [--help] [--version] <command> [<args>]\n";
  40 static const char dabba_more_info_string[] =
  41     "See 'dabba help <command>' for more info on a specific command.";
  42
  43 struct cmdname_help {
  44         char name[16];
  45         char help[80];
  46 };
  47
  48 void show_usage(const struct option *opt)
  49 {
  50         assert(opt);
  51
  52         printf("%s", dabba_usage_string);
  53
  54         if (opt != NULL) {
  55                 while (opt->name != NULL) {
  56                         printf("  --%s", opt->name);
  57                         if (opt->has_arg == required_argument)
  58                                 printf(" <arg>\n");
  59                         else if (opt->has_arg == optional_argument)
  60                                 printf(" [arg]\n");
  61                         else
  62                                 printf("\n");
  63                         opt++;
  64                 }
  65         }
  66 }
  67
  68 static inline void mput_char(char c, uint32_t num)
  69 {
  70         while (num--)
  71                 putchar(c);
  72 }
  73
  74 void help_unknown_cmd(const char *const cmd)
  75 {
  76         assert(cmd);
  77         printf("'%s' is not a dabba command. See 'dabba --help'.\n", cmd);
  78 }
  79
  80 static void list_common_cmds_help(void)
  81 {
  82         size_t i, longest = 0;
  83
  84         static struct cmdname_help common_cmds[] = {
  85                 {"interface", "perform an interface related command"},
  86                 {"capture", "capture live traffic from an interface"}
  87         };
  88
  89         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
  90                 if (longest < strlen(common_cmds[i].name))
  91                         longest = strlen(common_cmds[i].name);
  92         }
  93
  94         printf("The most commonly used dabba commands are:\n");
  95         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
  96                 printf("   %s   ", common_cmds[i].name);
  97                 mput_char(' ', longest - strlen(common_cmds[i].name));
  98                 printf("%s\n", common_cmds[i].help);
  99         }
 100 }
 101
 102 /**
 103  * \brief Print help
 104  * \param[in]           argc            Argument counter
 105  * \param[in]           argv            Argument vector
 106  * \return Returns 0 when the help could be printed, \c errno otherwise
 107  *
 108  * This function prints the basic dabba usage help message.
 109  * Furthermore, it lists all available command.
 110  */
 111
 112 int cmd_help(int argc, const char **argv)
 113 {
 114         char help_name[32];
 115         int rc = 0;
 116
 117         if (argc < 1 || !argv[0]) {
 118                 printf("usage: %s\n\n", dabba_usage_string);
 119                 list_common_cmds_help();
 120                 printf("\n%s\n", dabba_more_info_string);
 121         } else {
 122                 snprintf(help_name, sizeof(help_name), "dabba-%s", argv[0]);
 123                 rc = execlp("man", "man", help_name, (char *)NULL);
 124         }
 125
 126         return rc ? errno : rc;
 127 }
 128
 129 int cmd_version(int argc, const char **argv)
 130 {
 131         (void)argc;
 132         (void)argv;
 133
 134         printf("dabba version %s\n", DABBA_VERSION);
 135         return 0;
 136 }