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#include "configparser.h"
#include <algorithm>
#include <pwd.h>
#include <sys/types.h>
#include "config.h"
#include "configexception.h"
#include "confighandlerexception.h"
#include "filepath.h"
#include "logger.h"
#include "strprintf.h"
#include "utils.h"
namespace newsboat {
ConfigParser::ConfigParser()
{
register_handler("include", *this);
}
ConfigParser::~ConfigParser() {}
void ConfigParser::handle_action(const std::string& action,
const std::vector<std::string>& params)
{
/*
* ConfigParser also acts as ConfigActionHandler to implement
* recursive "include" command.
*/
if (action == "include") {
if (params.size() < 1) {
throw ConfigHandlerException(ActionHandlerStatus::TOO_FEW_PARAMS);
}
const Filepath path = Filepath::from_locale_string(params[0]);
const Filepath tilde_expanded = utils::resolve_tilde(path);
const Filepath current_fpath = included_files.back();
if (!this->parse_file(utils::resolve_relative(current_fpath, tilde_expanded))) {
throw ConfigHandlerException(ActionHandlerStatus::FILENOTFOUND);
}
} else {
throw ConfigHandlerException(ActionHandlerStatus::INVALID_COMMAND);
}
}
bool ConfigParser::parse_file(const Filepath& tmp_filename)
{
/*
* this function parses a config file.
*
* First, it checks whether this file has already been included, and if
* not, it does the following:
* - open the file
* - read it line by line
* - tokenize every line
* - if there is at least one token, look up a registered
* ConfigActionHandler to handle the command (which is specified in
* the first token)
* - hand over the tokenize results to the ConfigActionHandler
* - if an error happens, react accordingly.
*/
// It would be nice if this function was only give absolute paths, but the
// tests are easier as relative paths
const Filepath filename = tmp_filename.is_absolute() ?
tmp_filename :
utils::getcwd().join(tmp_filename);
if (std::find(included_files.begin(), included_files.end(),
filename) != included_files.end()) {
LOG(Level::WARN,
"ConfigParser::parse_file: file %s has already been "
"included",
filename);
return true;
}
included_files.push_back(filename);
const auto lines = utils::read_text_file(filename);
if (!lines) {
const auto error = lines.error();
switch (error.kind) {
case utils::ReadTextFileErrorKind::CantOpen:
LOG(Level::WARN,
"ConfigParser::parse_file: file %s couldn't be opened",
filename);
return false;
case utils::ReadTextFileErrorKind::LineError:
throw ConfigException(error.message);
}
}
unsigned int linecounter = 0;
std::string multi_line_buffer{};
for (const auto& line : lines.value()) {
linecounter++;
if (!line.empty() && line.back() == '\\') {
multi_line_buffer.append(line.substr(0, line.size()-1));
} else {
const std::string location = strprintf::fmt(_("%s line %u"), filename, linecounter);
if (!multi_line_buffer.empty()) {
multi_line_buffer.append(line);
LOG(Level::DEBUG, "ConfigParser::parse_file: tokenizing %s", multi_line_buffer);
parse_line(multi_line_buffer, location);
multi_line_buffer.clear();
} else {
LOG(Level::DEBUG, "ConfigParser::parse_file: tokenizing %s", line);
parse_line(line, location);
}
}
}
included_files.pop_back();
return true;
}
void ConfigParser::parse_line(const std::string& line,
const std::string& location)
{
auto stripped = utils::strip_comments(line);
auto evaluated = evaluate_backticks(std::move(stripped));
const auto token = utils::extract_token_quoted(evaluated);
if (token.has_value()) {
const std::string cmd = token.value();
const std::string params = evaluated;
if (action_handlers.count(cmd) < 1) {
throw ConfigException(strprintf::fmt(_("unknown command `%s'"), cmd));
}
ConfigActionHandler& handler = action_handlers.at(cmd);
try {
handler.handle_action(cmd, params);
} catch (const ConfigHandlerException& e) {
throw ConfigException(strprintf::fmt(
_("Error while processing command `%s' (%s): %s"),
line,
location,
e.what()));
}
}
}
void ConfigParser::register_handler(const std::string& cmd,
ConfigActionHandler& handler)
{
action_handlers.erase(cmd);
action_handlers.insert({cmd, handler});
}
/* Note that this function not only finds next backtick that isn't prefixed
* with a backslash, but also un-escapes all the escaped backticks it finds in
* the process */
std::string::size_type find_non_escaped_backtick(std::string& input,
const std::string::size_type startpos)
{
if (startpos == std::string::npos) {
return startpos;
}
std::string::size_type result = startpos;
result = input.find_first_of("`", result);
while (result != std::string::npos && result > 0 &&
input[result - 1] == '\\') {
// remove the backslash
input.erase(result - 1, 1);
// *not* adding one to start position as we already shortened
// the input by one character
result = input.find_first_of("`", result);
}
return result;
}
std::string ConfigParser::evaluate_backticks(std::string token)
{
std::string::size_type pos1 = find_non_escaped_backtick(token, 0);
std::string::size_type pos2 =
find_non_escaped_backtick(token, pos1 + 1);
while (pos1 != std::string::npos && pos2 != std::string::npos) {
const std::string cmd = token.substr(pos1 + 1, pos2 - pos1 - 1);
token.erase(pos1, pos2 - pos1 + 1);
std::string result = utils::get_command_output(cmd);
utils::trim_end(result);
token.insert(pos1, result);
pos1 = find_non_escaped_backtick(
token, pos1 + result.length() + 1);
pos2 = find_non_escaped_backtick(token, pos1 + 1);
}
return token;
}
} // namespace newsboat
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