1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <stdio.h>
18 #include <string>
19 #include <vector>
20 
21 #include <base/logging.h>
22 
23 #include "command.h"
24 
25 class HelpCommand : public Command {
26  public:
HelpCommand()27   HelpCommand()
28       : Command("help", "print help information for simpleperf",
29                 "Usage: simpleperf help [subcommand]\n"
30                 "    Without subcommand, print short help string for every subcommand.\n"
31                 "    With subcommand, print long help string for the subcommand.\n\n") {
32   }
33 
34   bool Run(const std::vector<std::string>& args) override;
35 
36  private:
37   void PrintShortHelp();
38   void PrintLongHelpForOneCommand(const Command& cmd);
39 };
40 
Run(const std::vector<std::string> & args)41 bool HelpCommand::Run(const std::vector<std::string>& args) {
42   if (args.size() == 1) {
43     PrintShortHelp();
44   } else {
45     Command* cmd = Command::FindCommandByName(args[1]);
46     if (cmd == nullptr) {
47       LOG(ERROR) << "malformed command line: can't find help string for unknown command " << args[0];
48       LOG(ERROR) << "try using \"--help\"";
49       return false;
50     } else {
51       PrintLongHelpForOneCommand(*cmd);
52     }
53   }
54   return true;
55 }
56 
PrintShortHelp()57 void HelpCommand::PrintShortHelp() {
58   printf("Usage: simpleperf [--help] subcommand [args_for_subcommand]\n\n");
59   for (auto& command : Command::GetAllCommands()) {
60     printf("%-20s%s\n", command->Name().c_str(), command->ShortHelpString().c_str());
61   }
62 }
63 
PrintLongHelpForOneCommand(const Command & command)64 void HelpCommand::PrintLongHelpForOneCommand(const Command& command) {
65   printf("%s\n", command.LongHelpString().c_str());
66 }
67 
68 HelpCommand help_command;
69