FileTools.cpp

/**
 * Copyright (c) 2012, OpenGeoSys Community (http://www.opengeosys.org)
 *            Distributed under a Modified BSD License.
 *              See accompanying file LICENSE.txt or
 *              http://www.opengeosys.org/project/license
 *
 *
 * \file FileTools.cpp
 *
 * Created on 2010-04-26 by Lars Bilke
 *
 */

#include "FileTools.h"
#include "StringTools.h"

#include <sys/stat.h>

namespace BaseLib
{

/**
 * Returns true if given file exists. From http://www.techbytes.ca/techbyte103.html
 */
bool IsFileExisting(const std::string &strFilename)
{
	struct stat stFileInfo;
	bool blnReturn;
	int intStat;

	// Attempt to get the file attributes
	intStat = stat(strFilename.c_str(),&stFileInfo);

	if(intStat == 0)
	{
		// We were able to get the file attributes
		// so the file obviously exists.
		blnReturn = true;
	}
	else
	{
		// We were not able to get the file attributes.
		// This may mean that we don't have permission to
		// access the folder which contains this file. If you
		// need to do that level of checking, lookup the
		// return values of stat which will give you
		// more details on why stat failed.
		blnReturn = false;
	}

	return(blnReturn);
}

/**
 * \brief truncate a file
 */
void truncateFile( std::string const& filename)
{
    std::ofstream ofs(filename.c_str(), std::ios_base::trunc);
    ofs.close();
}

/** Finds the position of last file path separator.
 * Checks for unix or windows file path separators in given path and returns the
 * position of the last one or std::string::npos if no file path separator was
 * found.
 */
size_t findLastPathSeparator(std::string const& path)
{
	return path.find_last_of("/\\");
}

/** Finds the position of last dot.
 * This could be used to extract file extension.
 */
size_t findLastDot(std::string const& path)
{
	return path.find_last_of(".");
}

/** Returns a string with file extension as found by getFileExtension()
 * dropped.
 */
std::string dropFileExtension(std::string const& filename)
{
	const size_t p = findLastDot(filename);
	if (p == std::string::npos)
		return filename;

	return filename.substr(0, p);
}

std::string extractBaseName(std::string const& pathname)
{
	const size_t p = findLastPathSeparator(pathname);
	return pathname.substr(p+1);
}

std::string extractBaseNameWithoutExtension(std::string const& pathname)
{
	std::string basename = extractBaseName(pathname);
	return dropFileExtension(basename);
}

std::string getFileExtension(const std::string &path)
{
	const std::string str = extractBaseName(path);
	const size_t p = findLastDot(str);
	if (p == std::string::npos)
		return std::string();
	return str.substr(p + 1);
}

bool hasFileExtension(std::string const& extension, std::string const& filename)
{
	std::string ext = stringToUpper(extension);	// Copy for modification.
	std::string file_ext = stringToUpper(getFileExtension(filename));

	return ext == file_ext;
}

std::string copyPathToFileName(const std::string &file_name,
    const std::string &source)
{
	// check if file_name already contains a full path
	const size_t pos = findLastPathSeparator(file_name);
	if (pos != std::string::npos)
		return file_name;

	return BaseLib::extractPath(source).append(file_name);
}

std::string extractPath(std::string const& pathname)
{
	const size_t pos = findLastPathSeparator(pathname);
	return pathname.substr(0, pos + 1);
}

} // end namespace BaseLib