ede/pekwm/CfgParserSource.cc
2011-10-23 00:10:40 +00:00

149 lines
2.7 KiB
C++

//
// Copyright © 2005-2009 Claes Nästén <me@pekdon.net>
//
// This program is licensed under the GNU GPL.
// See the LICENSE file for more information.
//
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif // HAVE_CONFIG_H
#include "CfgParserSource.hh"
#include "Util.hh"
#include <iostream>
#include <cstdio>
#include <cstdlib>
extern "C" {
#include <stdio.h>
#include <unistd.h>
}
using std::cerr;
using std::endl;
using std::string;
using std::fopen;
using std::fclose;
using std::exit;
unsigned int CfgParserSourceCommand::_sigaction_counter = 0;
/**
* Open file based configuration source.
*/
bool
CfgParserSourceFile::open(void)
throw (std::string&)
{
if (_file) {
throw string("TRYING TO OPEN ALLREADY OPEN SOURCE");
}
_file = fopen(_name.c_str(), "r");
if (! _file) {
throw string("failed to open file " + _name);
}
return true;
}
void
CfgParserSourceFile::close(void)
throw (std::string&)
{
if (! _file) {
throw string("trying to close already closed source");
}
fclose(_file);
_file = 0;
}
/**
* Run command and treat output as configuration source.
*/
bool
CfgParserSourceCommand::open(void)
throw (std::string&)
{
int fd[2];
int status;
status = pipe(fd);
if (status == -1) {
return false;
}
// Remove signal handler while parsing as otherwise reading from the
// pipe will break sometimes.
if (_sigaction_counter++ == 0) {
struct sigaction action;
action.sa_handler = SIG_DFL;
action.sa_mask = sigset_t();
action.sa_flags = 0;
sigaction(SIGCHLD, &action, &_sigaction);
}
_pid = fork();
if (_pid == -1) { // Error
return false;
} else if (_pid == 0) { // Child
dup2(fd[1], STDOUT_FILENO);
::close(fd[0]);
::close(fd[1]);
execlp("/bin/sh", "sh", "-c", _name.c_str(), (char *) 0);
// PRINT ERROR
::close (STDOUT_FILENO);
exit (1);
} else { // Parent
::close (fd[1]);
_file = ::fdopen(fd[0], "r");
}
return true;
}
/**
* Close source, wait for child process to finish.
*/
void
CfgParserSourceCommand::close(void)
throw (std::string&)
{
if (_sigaction_counter < 1) {
return;
}
_sigaction_counter--;
// Close source.
fclose(_file);
// Wait for process.
int status;
int pid_status;
status = waitpid(_pid, &pid_status, 0);
// If no other open CfgParserSourceCommand open, restore sigaction.
if (_sigaction_counter == 0) {
sigaction(SIGCHLD, &_sigaction, 0);
}
// Wait failed, throw error
if (status == -1) {
throw string("failed to wait for pid " + Util::to_string<int>(_pid));
}
}