src/cli/cmd_help.c

   1 /*
   2  * Copyright (C) the libgit2 contributors. All rights reserved.
   3  *
   4  * This file is part of libgit2, distributed under the GNU GPL v2 with
   5  * a Linking Exception. For full terms see the included COPYING file.
   6  */
   7
   8 #include <stdio.h>
   9 #include <git2.h>
  10 #include "cli.h"
  11 #include "cmd.h"
  12
  13 #define COMMAND_NAME "help"
  14
  15 static char *command;
  16 static int show_help;
  17
  18 static const cli_opt_spec opts[] = {
  19         { CLI_OPT_TYPE_SWITCH,   "help",     0, &show_help, 1,
  20           CLI_OPT_USAGE_HIDDEN,   NULL,     "display help about the help command" },
  21         { CLI_OPT_TYPE_ARG,      "command",  0, &command,   0,
  22           CLI_OPT_USAGE_DEFAULT, "command", "the command to show help for" },
  23         { 0 },
  24 };
  25
  26 static int print_help(void)
  27 {
  28         cli_opt_usage_fprint(stdout, PROGRAM_NAME, COMMAND_NAME, opts);
  29         printf("\n");
  30
  31         printf("Display help information about %s.  If a command is specified, help\n", PROGRAM_NAME);
  32         printf("about that command will be shown.  Otherwise, general information about\n");
  33         printf("%s will be shown, including the commands available.\n", PROGRAM_NAME);
  34
  35         return 0;
  36 }
  37
  38 static int print_commands(void)
  39 {
  40         const cli_cmd_spec *cmd;
  41
  42         cli_opt_usage_fprint(stdout, PROGRAM_NAME, NULL, cli_common_opts);
  43         printf("\n");
  44
  45         printf("These are the %s commands available:\n\n", PROGRAM_NAME);
  46
  47         for (cmd = cli_cmds; cmd->name; cmd++)
  48                 printf("   %-11s  %s\n", cmd->name, cmd->desc);
  49
  50         printf("\nSee '%s help <command>' for more information on a specific command.\n", PROGRAM_NAME);
  51
  52         return 0;
  53 }
  54
  55 int cmd_help(int argc, char **argv)
  56 {
  57         char *fake_args[2];
  58         const cli_cmd_spec *cmd;
  59         cli_opt invalid_opt;
  60
  61         if (cli_opt_parse(&invalid_opt, opts, argv + 1, argc - 1, CLI_OPT_PARSE_GNU))
  62                 return cli_opt_usage_error(COMMAND_NAME, opts, &invalid_opt);
  63
  64         /* Show the meta-help */
  65         if (show_help)
  66                 return print_help();
  67
  68         /* We were not asked to show help for a specific command. */
  69         if (!command)
  70                 return print_commands();
  71
  72         /*
  73          * If we were asked for help for a command (eg, `help <command>`),
  74          * delegate back to that command's `--help` option.  This lets
  75          * commands own their help.  Emulate the command-line arguments
  76          * that would invoke `<command> --help` and invoke that command.
  77          */
  78         fake_args[0] = command;
  79         fake_args[1] = "--help";
  80
  81         if ((cmd = cli_cmd_spec_byname(command)) == NULL)
  82                 return cli_error("'%s' is not a %s command. See '%s help'.",
  83                                 command, PROGRAM_NAME, PROGRAM_NAME);
  84
  85         return cmd->fn(2, fake_args);
  86 }