src/bin/lttng/commands/help.c

   1 /*
   2  * Copyright (C) 2015 - Philippe Proulx <pproulx@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _LGPL_SOURCE
  19 #include <popt.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23
  24 #include "../command.h"
  25 #include <common/utils.h>
  26
  27 enum {
  28         OPT_HELP = 1,
  29         OPT_LIST_OPTIONS,
  30 };
  31
  32 static struct poptOption long_options[] = {
  33         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  34         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  35         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  36         {0, 0, 0, 0, 0, 0, 0}
  37 };
  38
  39 /*
  40  *  cmd_help
  41  */
  42 int cmd_help(int argc, const char **argv, const struct cmd_struct commands[])
  43 {
  44         int opt, ret = CMD_SUCCESS;
  45         char *cmd_name;
  46         static poptContext pc;
  47         const struct cmd_struct *cmd;
  48         int found = 0;
  49
  50         pc = poptGetContext(NULL, argc, argv, long_options, 0);
  51         poptReadDefaultConfig(pc, 0);
  52
  53         while ((opt = poptGetNextOpt(pc)) != -1) {
  54                 switch (opt) {
  55                 case OPT_HELP:
  56                         SHOW_HELP();
  57                         goto end;
  58                 case OPT_LIST_OPTIONS:
  59                         list_cmd_options(stdout, long_options);
  60                         goto end;
  61                 default:
  62                         ret = CMD_UNDEFINED;
  63                         goto end;
  64                 }
  65         }
  66
  67         /* Get command name */
  68         cmd_name = (char *) poptGetArg(pc);
  69
  70         if (cmd_name == NULL) {
  71                 /* Fall back to lttng(1) */
  72                 ret = utils_show_man_page(1, "lttng");
  73
  74                 if (ret) {
  75                         ERR("Cannot view man page lttng(1)");
  76                         perror("exec");
  77                         ret = CMD_ERROR;
  78                         goto end;
  79                 }
  80         }
  81
  82         /* Make sure command name exists */
  83         cmd = &commands[0];
  84
  85         while (cmd->name != NULL) {
  86                 if (strcmp(cmd->name, cmd_name) == 0) {
  87                         found = 1;
  88                         break;
  89                 }
  90
  91                 cmd++;
  92         }
  93
  94         if (!found) {
  95                 ERR("Unknown command \"%s\"", cmd_name);
  96                 ret = CMD_ERROR;
  97                 goto end;
  98         }
  99
 100         /* Show command's man page */
 101         ret = show_cmd_man_page(cmd_name);
 102
 103         if (ret) {
 104                 ERR("Cannot view man page lttng-%s(1)", cmd_name);
 105                 perror("exec");
 106                 ret = CMD_ERROR;
 107         }
 108
 109 end:
 110         poptFreeContext(pc);
 111         return ret;
 112 }