util.cpp

// CS 225 util.h
// Created Spring 2011 by Jack Toole

#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <iostream>
#include "util.h"

extern char ** environ; // man 7 environ

namespace util
{

namespace internal
{
const char * error_prefix = "";

template<typename StrType>
void exit_if_error_output(const char * file, int32_t line, StrType message)
{
	if (util::internal::error_prefix != NULL)
		cerr << util::internal::error_prefix;
	cerr << file << ":" << line << ": " << message;
	if (errno != 0)
		cerr << ": " << strerror(errno);
	cerr << endl;
	exit(-1);
}

}

void SET_ERROR_MESSAGE(const char * message)
{
	internal::error_prefix = message;
}

namespace internal
{
namespace exec
{

char * allocateCstr(const string & str)
{
	char * cstr = new char[str.size() + 1];
	str.copy(cstr, str.size());
	cstr[str.size()] = '\0';
	return cstr;
}

pair<int, int> getFdsFromStream(const ostream * stream)
{
	int redirect_fd;
	int outpipe_fd = -1;

	if (stream == NULL)
		redirect_fd = -1;
	else if (stream == &cout || stream == &cerr) // we don't handle cerr right now; it is just left unpiped
		redirect_fd = STDOUT_FILENO;
	else
	{
		int pipe_fds[2];
		EXIT_IF_ERROR(pipe(pipe_fds) != 0);
		redirect_fd = pipe_fds[1];
		outpipe_fd = pipe_fds[0];
	}

	return make_pair(redirect_fd, outpipe_fd);
}

struct exec_timers
{
	struct itimerval remaining_real;
	struct itimerval remaining_virtual;
	struct itimerval remaining_prof;
	bool supports_virtual;
	bool supports_prof;
	exec_timers() : supports_virtual(true), supports_prof(true) { }
};

exec_timers get_exec_timers()
{
	exec_timers result;
	
	EXIT_IF_ERROR(getitimer(ITIMER_REAL, &result.remaining_real));
	
	if (getitimer(ITIMER_VIRTUAL, &result.remaining_virtual) != 0)
	{
		if (errno == EINVAL)
		{
			result.supports_virtual = false;
			errno = 0;
		}
		else
			exit_if_error_output(__FILE__, __LINE__, "getitimer(ITIMER_VIRTUAL) failed");
	}
	
	if (getitimer(ITIMER_PROF, &result.remaining_prof) != 0)
	{
		if (errno == EINVAL)
		{
			result.supports_prof = false;
			errno = 0;
		}
		else
			exit_if_error_output(__FILE__, __LINE__, "getitimer(ITIMER_PROF) failed");
	}

	return result;
}

void set_exec_timers(const exec_timers & timers)
{
	EXIT_IF_ERROR(setitimer(ITIMER_REAL, &timers.remaining_real, NULL));
	if (timers.supports_virtual) EXIT_IF_ERROR(setitimer(ITIMER_VIRTUAL, &timers.remaining_virtual, NULL));
	if (timers.supports_prof)    EXIT_IF_ERROR(setitimer(ITIMER_PROF,    &timers.remaining_prof, NULL));
}

void redirect_to_fd(const int redirect_fd)
{
	if (redirect_fd == -1)
	{
		int devnull_fd = open("/dev/null", O_WRONLY | O_NONBLOCK);
		close(STDOUT_FILENO);
		close(STDERR_FILENO);
		dup2(devnull_fd, STDOUT_FILENO);
		dup2(devnull_fd, STDERR_FILENO);
		close(devnull_fd);
	}
	else if (redirect_fd != STDOUT_FILENO)
	{
		close(STDOUT_FILENO);
		close(STDERR_FILENO);
		dup2(redirect_fd, STDOUT_FILENO);
		dup2(redirect_fd, STDERR_FILENO);
		close(redirect_fd);
	}
}

char ** cstr_array_from_vector_string(const string & command, const vector<string> & args)
{
	// TODO (toole1): check this doesn't cause a memleak
	char ** args_cstr = new char*[args.size() + 2];
	args_cstr[0] = allocateCstr(command);
	for (size_t i = 0; i < args.size(); i++)
		args_cstr[i + 1] = allocateCstr(args[i]);
	args_cstr[args.size() + 1] = NULL;
	return args_cstr;
}

} // namespace exec
} // namespace internal

// heavily refactored, but originally from:
// http://stackoverflow.com/questions/2180079/how-can-i-copy-a-file-on-unix-using-c
int8_t exec(const string & command, const vector<string> & args, ostream * output)
{
	using namespace internal;
	using namespace internal::exec;

	pair<int, int> fds = getFdsFromStream(output);
	int redirect_fd = fds.first;
	int outpipe_fd  = fds.second;

	exec_timers timers = get_exec_timers();
	
	pid_t pid = fork();
	EXIT_IF_ERROR(pid < 0);
	if (pid == 0)
	{
		set_exec_timers(timers);
		redirect_to_fd(redirect_fd);
		if (outpipe_fd != -1)
			close(outpipe_fd);

		// Sanitize environment
		char path[] = "PATH=/bin/:/usr/bin:/usr/local/bin";
        char libpath[] = "LD_LIBRARY_PATH=/software/intel-composer-2011u5-x86_64/lib/intel64/:$LD_LIBRARY_PATH"; // path for libiomp5.so
		// Turn off glibc errors default write-to-terminal behaviour, because
		// it does not get caught by stderr. This instead results in an abort.
		char redirect_glibc[] = "LIBC_FATAL_STDERR_=1";
		char * newenv[] = { path, libpath, redirect_glibc, NULL };
		environ = newenv;

		char ** args_cstr = cstr_array_from_vector_string(command, args);

		// Swap out child process image with the command, searching
		// in the specified path
		execvp(command.c_str(), args_cstr);
		
        // An error occured
		cerr << "exec(" << '\"' << command << '\"';
		for (size_t i = 0; i < args.size(); i++)
			cerr << ", \"" << args[i] << "\"";
		cerr << ") failed: " << strerror(errno) << endl;
		exit(-1);
	}
	else
	{
		// Take the output of the pipe and put it into the *output stream
		if (outpipe_fd != -1)
		{
			EXIT_IF_ERROR(output == NULL);
			close(redirect_fd);

			vector<char> buffer(1024);
			ssize_t char_read_count;
			do
			{
				errno = 0;
				char_read_count = ::read(outpipe_fd, &buffer[0], buffer.size() - 1);
				
				if (char_read_count < 0 && errno == EINTR) continue;
				EXIT_IF_ERROR(char_read_count < 0);
				EXIT_IF_ERROR(static_cast<size_t>(char_read_count) + 1 > buffer.size());
				
				buffer[char_read_count] = '\0';
				*output << &buffer[0];

			} while (char_read_count > 0);
		}

		int childExitStatus;
		/* parent - wait for child - this has all error handling, you
		 * could just call wait() as long as you are only expecting to
		 * have one child process at a time.
		 */
		pid_t ws = waitpid( pid, &childExitStatus, 0);
		EXIT_IF_ERROR(ws == -1);

		if (WIFEXITED(childExitStatus)) /* exit code in childExitStatus */
		{
			int8_t status = WEXITSTATUS(childExitStatus); /* zero is normal exit */
			/* handle non-zero as you wish */
			return status;
		}
		else if (WIFSIGNALED(childExitStatus)) /* killed */
		{
			// No idea why I'm doing this anymore... if it segfaults, you do too??
			kill(getpid(), WTERMSIG(childExitStatus));
			return -1;
		}
		else if (WIFSTOPPED(childExitStatus)) /* stopped */
		{
			//cout << "exec error: " << __LINE__ << endl;
			return -1;
		}
		else
			EXIT_IF_ERROR(true);
		exit(-1);
	}
}

// TODO (toole1) this is a total hack, should use execvp like exec() below
// originally from:
// http://stackoverflow.com/questions/2180079/how-can-i-copy-a-file-on-unix-using-c
int8_t exec(int redirect_fd, const string & command, const vector<string> & args)
{
	using namespace internal::exec;

	// For debugging:
#if 0
	cerr << "exec(" << '\"' << command << '\"';
	for (size_t i = 0; i < args.size(); i++)
		cerr << ", \"" << args[i] << "\"";
	cerr << ")" << endl;
#endif

	// avoid self destruction errors from closing then trying to duplicate output
	// you can't redirect to what's already there
	if (redirect_fd == STDOUT_FILENO || redirect_fd == STDERR_FILENO)
		redirect_fd = STDOUT_FILENO;

	// Save timer values :)
	// These are preserved across the parent, but not inherited by the child
	// let's change that
	struct itimerval remaining_real;
	struct itimerval remaining_virtual;
	struct itimerval remaining_prof;
	bool supports_virtual = true;
	bool supports_prof    = true;
	EXIT_IF_ERROR(getitimer(ITIMER_REAL,    &remaining_real));
	if (getitimer(ITIMER_VIRTUAL, &remaining_virtual) != 0)
	{
		if (errno == EINVAL)
		{
			supports_virtual = false;
			errno = 0;
		}
		else
			internal::exit_if_error_output(__FILE__, __LINE__, "getitimer(ITIMER_VIRTUAL) failed");
	}
	if (getitimer(ITIMER_PROF, &remaining_prof) != 0)
	{
		if (errno == EINVAL)
		{
			supports_prof = false;
			errno = 0;
		}
		else
			internal::exit_if_error_output(__FILE__, __LINE__, "getitimer(ITIMER_PROF) failed");
	}

	pid_t pid = fork();

	if (pid == 0) /* child */
	{

		// Restore timers
		EXIT_IF_ERROR(setitimer(ITIMER_REAL, &remaining_real, NULL));
		if (supports_virtual) EXIT_IF_ERROR(setitimer(ITIMER_VIRTUAL, &remaining_virtual, NULL));
		if (supports_prof)    EXIT_IF_ERROR(setitimer(ITIMER_PROF,    &remaining_prof, NULL));

		if (redirect_fd == -1)
		{
			int devnull_fd = open("/dev/null", O_WRONLY | O_NONBLOCK);
			close(STDOUT_FILENO);
			close(STDERR_FILENO);
			dup2(devnull_fd, STDOUT_FILENO);
			dup2(devnull_fd, STDERR_FILENO);
			close(devnull_fd);
		}
		else if (redirect_fd != STDOUT_FILENO)
		{
			close(STDOUT_FILENO);
			close(STDERR_FILENO);
			dup2(redirect_fd, STDOUT_FILENO);
			dup2(redirect_fd, STDERR_FILENO);
		}

		// Sanitize the environment
#if 1 //!! hack!
		char path[] = "PATH=/bin/:/usr/bin:/usr/local/bin";
		// Turn off glibc errors default write-to-terminal behaviour, because
		// it does not get caught by stderr. This instead results in an abort.
		char redirect_glibc[] = "LIBC_FATAL_STDERR_=1";
		char * newenv[] = { path, redirect_glibc, NULL };
		//char * newenv[] = { path, NULL };
		environ = newenv;
#endif

		// TODO (toole1): check this doesn't cause a memleak
		char ** args_cstr = new char*[args.size() + 2];
		args_cstr[0] = allocateCstr(command);
		for (size_t i = 0; i < args.size(); i++)
			args_cstr[i + 1] = allocateCstr(args[i]);
		args_cstr[args.size() + 1] = NULL;
		
		// Swap out child process image with the command, searching
		// in the specified path
		execvp(command.c_str(), args_cstr);
		
        // An error occured
		cerr << "exec(" << '\"' << command << '\"';
		for (size_t i = 0; i < args.size(); i++)
			cerr << ", \"" << args[i] << "\"";
		cerr << ") failed: " << strerror(errno) << endl;
		exit(-1);
	}
	else if (pid < 0)
	{
		/* error - couldn't start process - you decide how to handle */
		return -1;
	}
	else
	{
		int childExitStatus;
		/* parent - wait for child - this has all error handling, you
		 * could just call wait() as long as you are only expecting to
		 * have one child process at a time.
		 */
		pid_t ws = waitpid( pid, &childExitStatus, 0);
		if (ws == -1)
		{ /* error - handle as you wish */
			//cout << "exec error: " << __LINE__ << endl;
			return -1;
		}

		if (WIFEXITED(childExitStatus)) /* exit code in childExitStatus */
		{
			int8_t status = WEXITSTATUS(childExitStatus); /* zero is normal exit */
			/* handle non-zero as you wish */
			return status;
		}
		else if (WIFSIGNALED(childExitStatus)) /* killed */
		{
			kill(getpid(), WTERMSIG(childExitStatus));
			return -1;
		}
		else if (WIFSTOPPED(childExitStatus)) /* stopped */
		{
			//cout << "exec error: " << __LINE__ << endl;
			return -1;
		}
		else
			return -1;
	}
}


// originally from stackoverflow.com user plinth
// http://stackoverflow.com/questions/2180079/how-can-i-copy-a-file-on-unix-using-c
// Modified by Jack Toole
int8_t exec(int redirect_fd, const char * command,
            const char * arg1,
            const char * arg2,
            const char * arg3,
            const char * arg4,
            const char * arg5,
            const char * arg6)
{
	int childExitStatus;
	pid_t pid;

	const char * args[] = {arg1, arg2, arg3, arg4, arg5, arg6};
	const size_t args_count = (sizeof args) / (sizeof args[0]);

	// shift all nulls to end
	size_t first_null = 0;
	for (size_t i = 0; i < args_count; i++)
		if (args[i] != NULL)
			swap(args[i], args[first_null++]);

	// For debugging:
#if 0
	cerr << "exec(" << '\"' << command << '\"';
	for (size_t i = 0; i < args_count; i++)
		if (args[i] != NULL) cerr << ", \"" << args[i] << "\"";
	cerr << ")" << endl;
#endif

	// avoid self destruction errors from closing then trying to duplicate output
	// you can't redirect to what's already there
	if (redirect_fd == STDOUT_FILENO || redirect_fd == STDERR_FILENO)
		redirect_fd = STDOUT_FILENO;

	// Save timer values :)
	// These are preserved across the parent, but not inherited by the child
	// let's change that
	struct itimerval remaining_real;
	struct itimerval remaining_virtual;
	struct itimerval remaining_prof;
	bool supports_virtual = true;
	bool supports_prof    = true;
	EXIT_IF_ERROR(getitimer(ITIMER_REAL,    &remaining_real));
	if (getitimer(ITIMER_VIRTUAL, &remaining_virtual) != 0)
	{
		if (errno == EINVAL)
		{
			supports_virtual = false;
			errno = 0;
		}
		else
			internal::exit_if_error_output(__FILE__, __LINE__, "getitimer(ITIMER_VIRTUAL) failed");
	}
	if (getitimer(ITIMER_PROF, &remaining_prof) != 0)
	{
		if (errno == EINVAL)
		{
			supports_prof = false;
			errno = 0;
		}
		else
			internal::exit_if_error_output(__FILE__, __LINE__, "getitimer(ITIMER_PROF) failed");
	}

	pid = fork();

	if (pid == 0) /* child */
	{

		// Restore timers
		EXIT_IF_ERROR(setitimer(ITIMER_REAL, &remaining_real, NULL));
		if (supports_virtual) EXIT_IF_ERROR(setitimer(ITIMER_VIRTUAL, &remaining_virtual, NULL));
		if (supports_prof)    EXIT_IF_ERROR(setitimer(ITIMER_PROF,    &remaining_prof, NULL));

		if (redirect_fd == -1)
		{
			int devnull_fd = open("/dev/null", O_WRONLY | O_NONBLOCK);
			close(STDOUT_FILENO);
			close(STDERR_FILENO);
			dup2(devnull_fd, STDOUT_FILENO);
			dup2(devnull_fd, STDERR_FILENO);
			close(devnull_fd);
		}
		else if (redirect_fd != STDOUT_FILENO)
		{
			close(STDOUT_FILENO);
			close(STDERR_FILENO);
			dup2(redirect_fd, STDOUT_FILENO);
			dup2(redirect_fd, STDERR_FILENO);
		}

		// Sanitize the environment
#if 1 //!! hack!
		char path[] = "PATH=/bin/:/usr/bin:/usr/local/bin";
		// Turn off glibc errors default write-to-terminal behaviour, because
		// it does not get caught by stderr. This instead results in an abort.
		char redirect_glibc[] = "LIBC_FATAL_STDERR_=1";
		char * newenv[] = { path, redirect_glibc, NULL };
		//char * newenv[] = { path, NULL };
		environ = newenv;
#endif

		// Swap out child process image with the command, searching
		// in the specified path
		execlp(command, command, args[0], args[1], args[2], args[3], args[4], args[5], NULL);
		
        // An error occured
		cerr << "exec(" << '\"' << command << '\"';
		for (size_t i = 0; i < args_count; i++)
			if (args[i] != NULL) cerr << ", \"" << args[i] << "\"";
		cerr << ") failed: " << strerror(errno) << endl;
		exit(-1);
	}
	else if (pid < 0)
	{
		/* error - couldn't start process - you decide how to handle */
		return -1;
	}
	else
	{
		/* parent - wait for child - this has all error handling, you
		 * could just call wait() as long as you are only expecting to
		 * have one child process at a time.
		 */
		pid_t ws = waitpid( pid, &childExitStatus, 0);
		if (ws == -1)
		{ /* error - handle as you wish */
			//cout << "exec error: " << __LINE__ << endl;
			return -1;
		}

		if (WIFEXITED(childExitStatus)) /* exit code in childExitStatus */
		{
			int8_t status = WEXITSTATUS(childExitStatus); /* zero is normal exit */
			/* handle non-zero as you wish */
			return status;
		}
		else if (WIFSIGNALED(childExitStatus)) /* killed */
		{
			kill(getpid(), WTERMSIG(childExitStatus));
			return -1;
		}
		else if (WIFSTOPPED(childExitStatus)) /* stopped */
		{
			//cout << "exec error: " << __LINE__ << endl;
			return -1;
		}
		else
			return -1;
	}
}

const char * Signal::what() const
{
	const char * desc = strsignal(signum);
	return (desc == NULL) ? "Unknown Signal" : desc;
}


int chdir(const string & dir)
{
	return ::chdir(dir.c_str());
}

string stripTrailingSlash(const string & path)
{
	if (path[path.length() - 1] == '/')
		return path.substr(0, path.length() - 1);
	else
		return path;
}

string getBaseDir(const string & path)
{
	EXIT_IF_ERROR(path.length() == 0);
	if (path[path.length() - 1] == '/') return path;
	if (exists(path + "/")) return path + "/";
	size_t slash_pos = path.find_last_of('/');
	if (slash_pos == string::npos) return "./";
	return path.substr(0, slash_pos);
}

void assertExists(const string & path, int exit_code /* = -1 */)
{
	if (!exists(path))
	{
		cerr << "Error: " << path << " does not exist." << endl;
		exit(exit_code);
	}
}

bool exists(const string & path)
{
	// Try stat-ing it
	struct stat st;
	if (stat(path.c_str(), &st) != 0) return false;
	// Check for read permission
	if ((st.st_mode & S_IRUSR) == 0) return false;

	// Check for correct file/directory nature
	if (path[path.length()-1] != '/') return S_ISREG(st.st_mode);

	// Otherwise we want a directory
	if ((st.st_mode & S_IXUSR) == 0) return false;
	return S_ISDIR(st.st_mode);
}


mode_t permissions(const string & path)
{
	// Try stat-ing it
	struct stat st;
	if (stat(path.c_str(), &st) != 0) return -1;
	// Check for read permission
	if ((st.st_mode & S_IRUSR) == 0) return -1;

	return (st.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO));
}


void forceRemoveDir(string dir)
{
	size_t len = dir.length();
	if (dir[len-1] == '/') dir[len-1] = '\0';
	EXIT_IF_ERROR(exec("rm","-rf",dir.c_str()) != 0);
	if (dir[len-1] == '\0') dir[len-1] = '/';
}


string getcwdstr()
{
	int len = 256;
	char * buffer = new char[len];

	char * ret = getcwd(&buffer[0], len - 1);
	while (ret == NULL && errno == ERANGE)
	{
		len *= 2;

		delete buffer;
		buffer = new char[len];

		ret = getcwd(&buffer[0], len - 1);
	}

	EXIT_IF_ERROR(ret == NULL);

	string cwdstr(buffer);
	delete buffer;

	return cwdstr + "/";
}


void copyFile(const string & source, const string & dest)
{
	assertExists(source);
	vector<string> folders = tokenize(dest, '/');
	string currdir = "";
	for (size_t i = 0; i < folders.size() - 1; i++)
	{
		currdir += folders[i] + '/';
		if (!exists(currdir))
			exec("mkdir", currdir.c_str());
	}
	exec("cp", source.c_str(), dest.c_str());
}

void copyFiles(const string & sourceFolder, const string & destFolder, const vector<string> & files)
{
	assertExists(destFolder);
	for (size_t i = 0; i < files.size(); i++)
	{
		string sourceFile = sourceFolder + files[i];
		assertExists(sourceFile);
		copyFile(sourceFile, destFolder);
	}
}


void protectFiles(const string & folder, const vector<string> & files)
{
#if 0 // (debug)
	for (size_t i = 0; i < files.size(); i++)
	{
		string file = folder + files[i];
		assertExists(file);

		if (chmod(file.c_str(), S_IRUSR) != 0)
		{
			perror("chmod failed");
			exit(-1);
		}
	}
#endif
}

void protectDir(const string & dir)
{
	// (debug) EXIT_IF_ERROR(exec("/bin/chmod", "-R", "ugoa-w", dir.c_str()) != 0);
}

// Originally from Simon Biber
// http://bytes.com/topic/c/answers/545614-list-files-current-directory
vector<string> get_files_in_dir(const string & dir, bool concatdir /* = true */)
{
	EXIT_IF_ERROR(dir == "" || dir[dir.length()-1] != '/', "Directory name must end in a '/'");
	
	vector<string> files;
	DIR * dirp = opendir(dir.c_str());
	if (dirp == NULL) return files;
	
	struct dirent * ent = readdir(dirp);
	while (ent != NULL)
	{
		string file = ent->d_name;
		if (file != "." && file != "..")
			files.push_back(concatdir ? dir + file : file);
		ent = readdir(dirp);
	}

	closedir(dirp);
	return files;
}

bool is_symlink(const string & file)
{
	// Try lstat-ing it
	struct stat st;
	if (lstat(file.c_str(), &st) != 0) return -1;
	// Check for read permission
	if ((st.st_mode & S_IRUSR) == 0) return false;

	// & with symlink bit
	return (S_ISLNK(st.st_mode)) != 0;
}

string get_symlink_target(const string & symlink)
{
	const size_t buf_size = 4096;
	char buf[buf_size+1]; // TODO (toole1): hack-y value
	ssize_t len = readlink(symlink.c_str(), buf, buf_size);
	EXIT_IF_ERROR(len < 0 || static_cast<size_t>(len) == buf_size, "Error getting target of symlink " + symlink);
	buf[len] = '\0';
	return string(buf);
}

void linkDirs(const string & sourceFolder, const string & destFolder, const vector<string> & dirs)
{
	assertExists(destFolder);
	for (size_t i = 0; i < dirs.size(); i++)
	{
		string source = sourceFolder + dirs[i];
		string target = destFolder   + dirs[i];

		// Check for redundant monad/ directory
		// This allows the monad/ dir to be safely renamed
		if (replaceFirst(source, "/../monad/","/"))
			replaceFirst(target, "/monad/","/");

		assertExists(destFolder + source + '/');

		if (symlink(source.c_str(), target.c_str()) != 0)
		{
			cerr << "symlink failed: " << target << ": ";
			perror(NULL);
			exit(-1);
		}
	}
}


bool replaceFirst(string & str, const string & toreplace, const string & with)
{
	size_t i = str.find(toreplace);
	if (i != string::npos)
	{
		str.replace(i,toreplace.length(),with);
		return true;
	}
	return false;
}

size_t replaceAll(string & str, const string & toreplace, const string & with)
{
	size_t i = str.find(toreplace);
	size_t count = 0;

	while (i != string::npos)
	{
		str.replace(i,toreplace.length(),with);
		i = str.find(toreplace, i + with.length());
		count++;
	}

	return count;
}

size_t replaceAllInternal(string & str, const string & toreplace, const string & with)
{
	size_t i = str.find(toreplace);
	size_t count = 0;

	while ((i != string::npos) && (i != str.length() - toreplace.length()))
	{
		str.replace(i,toreplace.length(),with);
		i = str.find(toreplace, i + with.length());
		count++;
	}

	return count;
}


size_t findNthLast(const string & str, char c, size_t n)
{
	if (str.length() == 0) return string::npos;
	size_t i = str.length() - 1;

	do
	{
		if (str[i] == c) n--;
		if (n == 0) return i;
	} while (i-- != 0);

	return string::npos;
}


string read_string_from_FILE(FILE * file, size_t max_length /* = -1 */)
{
	vector<char> v;
	v.reserve(256);

	while (true) 
	{
		int nextchar = fgetc(file);
		if (nextchar == '\0' || nextchar == EOF)
			break;
		if (v.size() < max_length)
			v.push_back(nextchar);
	}

	if (v.size() == max_length)
	{
		v.push_back('.');
		v.push_back('.');
		v.push_back('.');
	}

	v.push_back('\0');

	return string(&v[0]);
}

void write_string_to_FILE(FILE * file, const char * str)
{
	fflush(file);
	size_t i = 0;
	do
	{
//		cout << (int)str[i] << ' ';
		fputc(str[i], file);

		// We use a do-while because we want the \0 to be written to the stream
		// for sending multiple strings
	} while (str[i++] != 0);

//	cout << endl;

	fflush(file);
}



/**
*
*
**/

string readFile(const string & filename)
{
	ifstream file;
	file.open(filename.c_str());
	if (!file.good())
		return "";
	
	stringbuf linebuf;
	file.get(linebuf, '\0');
	linebuf.pubsync();
	return linebuf.str();
}


void readConfig(const string & testsFolder, FileMap & map, const string & discriminator /* = "" */)
{
	string file;
	if (testsFolder == "" || testsFolder[testsFolder.length()-1] == '/')
		file = testsFolder + "config.ini";
	else
		file = testsFolder;
	readFileGeneric(file, &map, NULL, discriminator);
}

void readFile(const string & file, vector<string> & lines)
{
	readFileGeneric(file, NULL, &lines);
}

void readFileGeneric(const string & filename, FileMap * map, vector<string> * lines, const string & discriminator /* = "" */)
{
	ifstream infile;
	istream * fileptr;
	if (filename == "/dev/stdin")
		fileptr = &cin;
	else
	{
		fileptr = &infile;
		infile.open(filename.c_str(), fstream::in);
	}
	istream & file = *fileptr;

	vector<string> * section = NULL;
	if (map != NULL) section = &(*map)[""];
	else section = lines;

	while ((file.good() && file.peek() == '\n') || file.peek() == '\r')
		file.get(); // get '\n'

	while (file.good())
	{
		// Read a line - A lot of code, I know, right?
		stringbuf linebuf;
		file.get(linebuf);
		while ((file.good() && file.peek() == '\n') || file.peek() == '\r')
			file.get(); // get '\n'
		linebuf.pubsync();
		string line = linebuf.str();
		int len = line.length();
		if (len == 0) continue;

        if (line[len-1] == '\r')
            line.replace(--len,1,"");

		if (len == 0 || line[0] == ';') continue; // skip comments
		
		if (map != NULL)
		{
			// Update the section
			if (line[0] == '[' && line[len-1] == ']')
			{
				section = &(*map)[line.substr(1, len - 2)];
				continue;
			}
			else if (line[0] == '[' || line[len-1] == ']')
			{
				cout << "config.ini: Format error: " << line << endl;
				exit(-1);
			}
		}

		// Or add the line/file to the section
		size_t delim_pos = line.find_first_of("?:");
		if (delim_pos == string::npos || map == NULL)
			section->push_back(line);
		else if ((line[delim_pos] == ':' && (delim_pos == 0 || discriminator == "")) ||
		         line.compare(0, delim_pos, discriminator) == 0)
			section->push_back(line.substr(delim_pos+1, line.size()-delim_pos-1));
	}

	if (filename != "/dev/stdin")
		infile.close();
}


OptionsParser::OptionsParser()
{
	valueMap[""]      = true;

	valueMap["yes"]   = true;
	valueMap["no"]    = false;

	valueMap["on"]    = true;
	valueMap["off"]   = false;

	valueMap["true"]  = true;
	valueMap["false"] = false;

	valueMap["1"]     = true;
	valueMap["0"]     = false;