dabba/help.c

   1 /**
   2  * \file help.c
   3  * \author written by Emmanuel Roullit emmanuel.roullit@gmail.com (C) 2013
   4  * \date 2013
   5  */
   6
   7
   8 #include <stdio.h>
   9 #include <string.h>
  10 #include <unistd.h>
  11 #include <errno.h>
  12 #include <getopt.h>
  13 #include <assert.h>
  14 #include <limits.h>
  15 #include <libdabba/macros.h>
  16
  17 static const char dabba_usage_string[] =
  18     "dabba [--help] [--version] <command> [<subcommand>] <action> [<args>]\n";
  19 static const char dabba_more_info_string[] =
  20     "See 'dabba help <command> [<subcommand>]' for more specific information.";
  21
  22 struct cmdname_help {
  23         char name[16];
  24         char help[80];
  25 };
  26
  27 /**
  28  * \brief print option list to \c stdout
  29  * \param[in]           opt             Pointer to option array
  30  */
  31
  32 void show_usage(const struct option *opt)
  33 {
  34         assert(opt);
  35
  36         printf("%s", dabba_usage_string);
  37
  38         while (opt->name != NULL) {
  39                 printf("  --%s", opt->name);
  40                 if (opt->has_arg == required_argument)
  41                         printf(" <arg>\n");
  42                 else if (opt->has_arg == optional_argument)
  43                         printf(" [arg]\n");
  44                 else
  45                         printf("\n");
  46                 opt++;
  47         }
  48 }
  49
  50 /**
  51  * \internal
  52  * \brief add some indenting on \c stdout
  53  * \param[in]           c               Character to indent
  54  * \param[in]           num             Indent level
  55  */
  56
  57 static inline void mput_char(const char c, uint32_t num)
  58 {
  59         while (num--)
  60                 putchar(c);
  61 }
  62
  63 /**
  64  * \brief print on \c stdout that the invoked command is unknown
  65  * \param[in]           cmd             Pointer to invoked command string
  66  */
  67
  68 void help_unknown_cmd(const char *const cmd)
  69 {
  70         assert(cmd);
  71         printf("'%s' is not a dabba command. See 'dabba --help'.\n", cmd);
  72 }
  73
  74 /**
  75  * \brief list on \c stdout the commonly used commands.
  76  */
  77
  78 static void list_common_cmds_help(void)
  79 {
  80         size_t i, longest = 0;
  81
  82         static struct cmdname_help common_cmds[] = {
  83                 {"interface", "perform an interface related command"},
  84                 {"thread", "perform a thread related command"},
  85                 {"capture", "capture live traffic from an interface"},
  86                 {"replay", "replay traffic from a pcap file"}
  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[NAME_MAX];
 115         int rc = 0, a;
 116         size_t offset;
 117
 118         if (argc < 1 || !argv[0]) {
 119                 printf("usage: %s\n\n", dabba_usage_string);
 120                 list_common_cmds_help();
 121                 printf("\n%s\n", dabba_more_info_string);
 122         } else {
 123                 offset = snprintf(help_name, sizeof(help_name), "dabba");
 124
 125                 for (a = 0; a < argc; a++)
 126                         offset +=
 127                             snprintf(&help_name[offset],
 128                                      sizeof(help_name) - offset, "-%s",
 129                                      argv[a]);
 130
 131                 rc = execlp("man", "man", help_name, NULL);
 132         }
 133
 134         return rc ? errno : rc;
 135 }
 136
 137 /**
 138  * \brief Print tool version number to \c stdout
 139  * \param[in]           argc            Argument counter
 140  * \param[in]           argv            Argument vector
 141  * \return Always returns zero.
 142  */
 143
 144 int cmd_version(int argc, const char **argv)
 145 {
 146         (void)argc;
 147         (void)argv;
 148
 149         printf("dabba version %s\n", DABBA_VERSION);
 150         return 0;
 151 }