console.cpp

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/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <https://www.gnu.org/licenses/old-licenses/gpl-2.0>.
 */

 
#include "stdafx.h"
#include "core/string_builder.hpp"
#include "core/string_consumer.hpp"
#include "console_internal.h"
#include "network/network.h"
#include "network/network_func.h"
#include "network/network_admin.h"
#include "debug.h"
#include "console_func.h"
#include "settings_type.h"
 
#include "safeguards.h"
 
static const uint ICON_MAX_RECURSE = 10;     
 
/* console parser */
/* static */ IConsole::CommandList &IConsole::Commands()
{
  static IConsole::CommandList cmds;
  return cmds;
}
 
/* static */ IConsole::AliasList &IConsole::Aliases()
{
  static IConsole::AliasList aliases;
  return aliases;
}
 
std::optional<FileHandle> _iconsole_output_file;
 
void IConsoleInit()
{
  _iconsole_output_file = std::nullopt;
  _redirect_console_to_client = INVALID_CLIENT_ID;
  _redirect_console_to_admin  = AdminID::Invalid();
 
  IConsoleGUIInit();
 
  IConsoleStdLibRegister();
}
 
static void IConsoleWriteToLogFile(const std::string &string)
{
  if (_iconsole_output_file.has_value()) {
    /* if there is an console output file ... also print it there */
    try {
      fmt::print(*_iconsole_output_file, "{}{}\n", GetLogPrefix(), string);
    } catch (const std::system_error &) {
      _iconsole_output_file.reset();
      IConsolePrint(CC_ERROR, "Cannot write to console log file; closing the log file.");
    }
  }
}
 
bool CloseConsoleLogIfActive()
{
  if (_iconsole_output_file.has_value()) {
    IConsolePrint(CC_INFO, "Console log file closed.");
    _iconsole_output_file.reset();
    return true;
  }
 
  return false;
}
 
void IConsoleFree()
{
  IConsoleGUIFree();
  CloseConsoleLogIfActive();
}

void IConsolePrint(TextColour colour_code, const std::string &string)
{
  assert(IsValidConsoleColour(colour_code));
 
  if (_redirect_console_to_client != INVALID_CLIENT_ID) {
    /* Redirect the string to the client */
    NetworkServerSendRcon(_redirect_console_to_client, colour_code, string);
    return;
  }
 
  if (_redirect_console_to_admin != AdminID::Invalid()) {
    NetworkServerSendAdminRcon(_redirect_console_to_admin, colour_code, string);
    return;
  }
 
  /* Create a copy of the string, strip it of colours and invalid
   * characters and (when applicable) assign it to the console buffer */
  std::string str = StrMakeValid(string, {});
 
  if (_network_dedicated) {
    NetworkAdminConsole("console", str);
    fmt::print("{}{}\n", GetLogPrefix(), str);
    fflush(stdout);
    IConsoleWriteToLogFile(str);
    return;
  }
 
  IConsoleWriteToLogFile(str);
  IConsoleGUIPrint(colour_code, str);
}

static std::string RemoveUnderscores(std::string name)
{
  name.erase(std::remove(name.begin(), name.end(), '_'), name.end());
  return name;
}

/* static */ void IConsole::CmdRegister(const std::string &name, IConsoleCmdProc *proc, IConsoleHook *hook)
{
  IConsole::Commands().try_emplace(RemoveUnderscores(name), name, proc, hook);
}

/* static */ IConsoleCmd *IConsole::CmdGet(const std::string &name)
{
  auto item = IConsole::Commands().find(RemoveUnderscores(name));
  if (item != IConsole::Commands().end()) return &item->second;
  return nullptr;
}

/* static */ void IConsole::AliasRegister(const std::string &name, std::string_view cmd)
{
  auto result = IConsole::Aliases().try_emplace(RemoveUnderscores(name), name, cmd);
  if (!result.second) IConsolePrint(CC_ERROR, "An alias with the name '{}' already exists.", name);
}

/* static */ IConsoleAlias *IConsole::AliasGet(const std::string &name)
{
  auto item = IConsole::Aliases().find(RemoveUnderscores(name));
  if (item != IConsole::Aliases().end()) return &item->second;
  return nullptr;
}

static void IConsoleAliasExec(const IConsoleAlias *alias, std::span<std::string> tokens, uint recurse_count)
{
  Debug(console, 6, "Requested command is an alias; parsing...");
 
  if (recurse_count > ICON_MAX_RECURSE) {
    IConsolePrint(CC_ERROR, "Too many alias expansions, recursion limit reached.");
    return;
  }
 
  std::string buffer;
  StringBuilder builder{buffer};
 
  StringConsumer consumer{alias->cmdline};
  while (consumer.AnyBytesLeft()) {
    auto c = consumer.TryReadUtf8();
    if (!c.has_value()) {
      IConsolePrint(CC_ERROR, "Alias '{}' ('{}') contains malformed characters.", alias->name, alias->cmdline);
      return;
    }
 
    switch (*c) {
      case '\'': // ' will double for ""
        builder.PutChar('\"');
        break;
 
      case ';': // Cmd separator; execute previous and start new command
        IConsoleCmdExec(builder.GetString(), recurse_count);
 
        buffer.clear();
        break;
 
      case '%': // Some or all parameters
        c = consumer.ReadUtf8();
        switch (*c) {
          case '+': { // All parameters separated: "[param 1]" "[param 2]"
            for (size_t i = 0; i < tokens.size(); ++i) {
              if (i != 0) builder.PutChar(' ');
              builder.PutChar('\"');
              builder += tokens[i];
              builder.PutChar('\"');
            }
            break;
          }
 
          case '!': { // Merge the parameters to one: "[param 1] [param 2] [param 3...]"
            builder.PutChar('\"');
            for (size_t i = 0; i < tokens.size(); ++i) {
              if (i != 0) builder.PutChar(' ');
              builder += tokens[i];
            }
            builder.PutChar('\"');
            break;
          }
 
          default: { // One specific parameter: %A = [param 1] %B = [param 2] ...
            size_t param = *c - 'A';
 
            if (param >= tokens.size()) {
              IConsolePrint(CC_ERROR, "Too many or wrong amount of parameters passed to alias.");
              IConsolePrint(CC_HELP, "Usage of alias '{}': '{}'.", alias->name, alias->cmdline);
              return;
            }
 
            builder.PutChar('\"');
            builder += tokens[param];
            builder.PutChar('\"');
            break;
          }
        }
        break;
 
      default:
        builder.PutUtf8(*c);
        break;
    }
  }
 
  IConsoleCmdExec(builder.GetString(), recurse_count);
}

void IConsoleCmdExec(std::string_view command_string, const uint recurse_count)
{
  if (command_string[0] == '#') return; // comments
 
  Debug(console, 4, "Executing cmdline: '{}'", command_string);
 
  std::string buffer;
  StringBuilder builder{buffer};
  StringConsumer consumer{command_string};
 
  std::vector<std::string> tokens;
  bool found_token = false;
  bool in_quotes = false;
 
  /* 1. Split up commandline into tokens, separated by spaces, commands
   * enclosed in "" are taken as one token. We can only go as far as the amount
   * of characters in our stream or the max amount of tokens we can handle */
  while (consumer.AnyBytesLeft()) {
    auto c = consumer.TryReadUtf8();
    if (!c.has_value()) {
      IConsolePrint(CC_ERROR, "Command '{}' contains malformed characters.", command_string);
      return;
    }
 
    switch (*c) {
      case ' ': // Token separator
        if (!found_token) break;
 
        if (in_quotes) {
          builder.PutUtf8(*c);
          break;
        }
 
        tokens.emplace_back(std::move(buffer));
        buffer.clear();
        found_token = false;
        break;
 
      case '"': // Tokens enclosed in "" are one token
        in_quotes = !in_quotes;
        found_token = true;
        break;
 
      case '\\': // Escape character for ""
        if (consumer.ReadUtf8If('"')) {
          builder.PutUtf8('"');
          break;
        }
        [[fallthrough]];
 
      default: // Normal character
        builder.PutUtf8(*c);
        found_token = true;
        break;
    }
  }
 
  if (found_token) {
    tokens.emplace_back(std::move(buffer));
    buffer.clear();
  }
 
  for (size_t i = 0; i < tokens.size(); i++) {
    Debug(console, 8, "Token {} is: '{}'", i, tokens[i]);
  }
 
  if (tokens.empty() || tokens[0].empty()) return; // don't execute empty commands
  /* 2. Determine type of command (cmd or alias) and execute
   * First try commands, then aliases. Execute
   * the found action taking into account its hooking code
   */
  IConsoleCmd *cmd = IConsole::CmdGet(tokens[0]);
  if (cmd != nullptr) {
    ConsoleHookResult chr = (cmd->hook == nullptr ? CHR_ALLOW : cmd->hook(true));
    switch (chr) {
      case CHR_ALLOW: {
        std::vector<std::string_view> views;
        for (auto &token : tokens) views.emplace_back(token);
        if (!cmd->proc(views)) { // index started with 0
          cmd->proc({}); // if command failed, give help
        }
        return;
      }
 
      case CHR_DISALLOW: return;
      case CHR_HIDE: break;
    }
  }
 
  IConsoleAlias *alias = IConsole::AliasGet(tokens[0]);
  if (alias != nullptr) {
    IConsoleAliasExec(alias, std::span(tokens).subspan(1), recurse_count + 1);
    return;
  }
 
  IConsolePrint(CC_ERROR, "Command '{}' not found.", tokens[0]);
}