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#include "configparser.h"
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <pwd.h>
#include <sys/types.h>
#include "config.h"
#include "exceptions.h"
#include "logger.h"
#include "strprintf.h"
#include "tagsouppullparser.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);
}
if (!this->parse(utils::resolve_tilde(params[0])))
throw ConfigHandlerException(
ActionHandlerStatus::FILENOTFOUND);
} else
throw ConfigHandlerException(
ActionHandlerStatus::INVALID_COMMAND);
}
bool ConfigParser::parse(const std::string& filename, bool double_include)
{
/*
* 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.
*/
if (!double_include &&
included_files.find(filename) != included_files.end()) {
LOG(Level::WARN,
"ConfigParser::parse: file %s has already been "
"included",
filename);
return true;
}
included_files.insert(included_files.begin(), filename);
unsigned int linecounter = 0;
std::ifstream f(filename.c_str());
std::string line;
if (!f.is_open()) {
LOG(Level::WARN,
"ConfigParser::parse: file %s couldn't be opened",
filename);
return false;
}
while (f.is_open() && !f.eof()) {
getline(f, line);
++linecounter;
LOG(Level::DEBUG, "ConfigParser::parse: tokenizing %s", line);
std::vector<std::string> tokens = utils::tokenize_quoted(line);
if (!tokens.empty()) {
std::string cmd = tokens[0];
ConfigActionHandler* handler = action_handlers[cmd];
if (handler) {
tokens.erase(
tokens.begin()); // delete first element
try {
evaluate_backticks(tokens);
handler->handle_action(cmd, tokens);
} catch (const ConfigHandlerException& e) {
throw ConfigException(strprintf::fmt(
_("Error while processing "
"command `%s' (%s line %u): "
"%s"),
line,
filename,
linecounter,
e.what()));
}
} else {
throw ConfigException(strprintf::fmt(
_("unknown command `%s'"), cmd));
}
}
}
return true;
}
void ConfigParser::register_handler(const std::string& cmd,
ConfigActionHandler* handler)
{
action_handlers[cmd] = handler;
}
void ConfigParser::unregister_handler(const std::string& cmd)
{
action_handlers[cmd] = 0;
}
void ConfigParser::evaluate_backticks(std::vector<std::string>& tokens)
{
for (auto& token : tokens) {
token = evaluate_backticks(token);
}
}
/* 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) {
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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