X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Ffilesys.cpp;h=f61b39b9465b191badf70befdb27da41e27b13f5;hb=09f9e465e760cb8fd791222405a9e5e68a676ba0;hp=8248a13d46f3703c48061faa68f3b2e150289f8e;hpb=7cfb71385d00d1cbbbfd9c76f6c01adafa9e648a;p=oweals%2Fminetest.git

diff --git a/src/filesys.cpp b/src/filesys.cpp
index 8248a13d4..f61b39b94 100644
--- a/src/filesys.cpp
+++ b/src/filesys.cpp
@@ -1,26 +1,35 @@
 /*
-Minetest-c55
-Copyright (C) 2010 celeron55, Perttu Ahola <celeron55@gmail.com>
+Minetest
+Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
 
 This program is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
 (at your option) any later version.
 
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
+GNU Lesser General Public License for more details.
 
-You should have received a copy of the GNU General Public License along
+You should have received a copy of the GNU Lesser General Public License along
 with this program; if not, write to the Free Software Foundation, Inc.,
 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
 #include "filesys.h"
-#include "strfnd.h"
+#include "util/string.h"
 #include <iostream>
-#include <string.h>
+#include <cstdio>
+#include <cstring>
+#include <cerrno>
+#include <fstream>
+#include "log.h"
+#include "config.h"
+#include "porting.h"
+#ifdef __ANDROID__
+#include "settings.h" // For g_settings
+#endif
 
 namespace fs
 {
@@ -28,57 +37,29 @@ namespace fs
 #ifdef _WIN32 // WINDOWS
 
 #define _WIN32_WINNT 0x0501
-#include <Windows.h>
-#include <stdio.h>
-#include <malloc.h>
-#include <tchar.h> 
-#include <wchar.h> 
-#include <stdio.h>
-
-#define BUFSIZE MAX_PATH
+#include <windows.h>
+#include <shlwapi.h>
 
-std::vector<DirListNode> GetDirListing(std::string pathstring)
+std::vector<DirListNode> GetDirListing(const std::string &pathstring)
 {
 	std::vector<DirListNode> listing;
 
 	WIN32_FIND_DATA FindFileData;
 	HANDLE hFind = INVALID_HANDLE_VALUE;
 	DWORD dwError;
-	LPTSTR DirSpec;
-	INT retval;
-
-	DirSpec = (LPTSTR) malloc (BUFSIZE);
-
-	if( DirSpec == NULL )
-	{
-	  printf( "Insufficient memory available\n" );
-	  retval = 1;
-	  goto Cleanup;
-	}
 
-	// Check that the input is not larger than allowed.
-	if (pathstring.size() > (BUFSIZE - 2))
-	{
-	  _tprintf(TEXT("Input directory is too large.\n"));
-	  retval = 3;
-	  goto Cleanup;
-	}
-
-	//_tprintf (TEXT("Target directory is %s.\n"), pathstring.c_str());
-
-	sprintf(DirSpec, "%s", (pathstring + "\\*").c_str());
+	std::string dirSpec = pathstring + "\\*";
 
 	// Find the first file in the directory.
-	hFind = FindFirstFile(DirSpec, &FindFileData);
+	hFind = FindFirstFile(dirSpec.c_str(), &FindFileData);
 
-	if (hFind == INVALID_HANDLE_VALUE) 
-	{
-	  _tprintf (TEXT("Invalid file handle. Error is %u.\n"), 
-				GetLastError());
-	  retval = (-1);
-	} 
-	else 
-	{
+	if (hFind == INVALID_HANDLE_VALUE) {
+		dwError = GetLastError();
+		if (dwError != ERROR_FILE_NOT_FOUND && dwError != ERROR_PATH_NOT_FOUND) {
+			errorstream << "GetDirListing: FindFirstFile error."
+					<< " Error is " << dwError << std::endl;
+		}
+	} else {
 		// NOTE:
 		// Be very sure to not include '..' in the results, it will
 		// result in an epic failure when deleting stuff.
@@ -86,12 +67,11 @@ std::vector<DirListNode> GetDirListing(std::string pathstring)
 		DirListNode node;
 		node.name = FindFileData.cFileName;
 		node.dir = FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
-		if(node.name != "." && node.name != "..")
+		if (node.name != "." && node.name != "..")
 			listing.push_back(node);
 
 		// List all the other files in the directory.
-		while (FindNextFile(hFind, &FindFileData) != 0) 
-		{
+		while (FindNextFile(hFind, &FindFileData) != 0) {
 			DirListNode node;
 			node.name = FindFileData.cFileName;
 			node.dir = FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
@@ -101,29 +81,17 @@ std::vector<DirListNode> GetDirListing(std::string pathstring)
 
 		dwError = GetLastError();
 		FindClose(hFind);
-		if (dwError != ERROR_NO_MORE_FILES) 
-		{
-		 _tprintf (TEXT("FindNextFile error. Error is %u.\n"), 
-				   dwError);
-		retval = (-1);
-		goto Cleanup;
-		}
+		if (dwError != ERROR_NO_MORE_FILES) {
+			errorstream << "GetDirListing: FindNextFile error."
+					<< " Error is " << dwError << std::endl;
+			listing.clear();
+			return listing;
+ 		}
 	}
-	retval  = 0;
-
-Cleanup:
-	free(DirSpec);
-
-	if(retval != 0) listing.clear();
-
-	//for(unsigned int i=0; i<listing.size(); i++){
-	//	std::cout<<listing[i].name<<(listing[i].dir?" (dir)":" (file)")<<std::endl;
-	//}
-	
 	return listing;
 }
 
-bool CreateDir(std::string path)
+bool CreateDir(const std::string &path)
 {
 	bool r = CreateDirectory(path.c_str(), NULL);
 	if(r == true)
@@ -133,128 +101,228 @@ bool CreateDir(std::string path)
 	return false;
 }
 
-bool PathExists(std::string path)
+bool PathExists(const std::string &path)
 {
 	return (GetFileAttributes(path.c_str()) != INVALID_FILE_ATTRIBUTES);
 }
 
-bool RecursiveDelete(std::string path)
+bool IsPathAbsolute(const std::string &path)
 {
-	std::cerr<<"Removing \""<<path<<"\""<<std::endl;
+	return !PathIsRelative(path.c_str());
+}
 
-	//return false;
-	
-	// This silly function needs a double-null terminated string...
-	// Well, we'll just make sure it has at least two, then.
-	path += "\0\0";
-
-	SHFILEOPSTRUCT sfo;
-	sfo.hwnd = NULL;
-	sfo.wFunc = FO_DELETE;
-	sfo.pFrom = path.c_str();
-	sfo.pTo = NULL;
-	sfo.fFlags = FOF_SILENT | FOF_NOCONFIRMATION | FOF_NOCONFIRMMKDIR;
-	
-	int r = SHFileOperation(&sfo);
-
-	if(r != 0)
-		std::cerr<<"SHFileOperation returned "<<r<<std::endl;
-
-	//return (r == 0);
+bool IsDir(const std::string &path)
+{
+	DWORD attr = GetFileAttributes(path.c_str());
+	return (attr != INVALID_FILE_ATTRIBUTES &&
+			(attr & FILE_ATTRIBUTE_DIRECTORY));
+}
+
+bool IsDirDelimiter(char c)
+{
+	return c == '/' || c == '\\';
+}
+
+bool RecursiveDelete(const std::string &path)
+{
+	infostream << "Recursively deleting \"" << path << "\"" << std::endl;
+	if (!IsDir(path)) {
+		infostream << "RecursiveDelete: Deleting file  " << path << std::endl;
+		if (!DeleteFile(path.c_str())) {
+			errorstream << "RecursiveDelete: Failed to delete file "
+					<< path << std::endl;
+			return false;
+		}
+		return true;
+	}
+	infostream << "RecursiveDelete: Deleting content of directory "
+			<< path << std::endl;
+	std::vector<DirListNode> content = GetDirListing(path);
+	for (const DirListNode &n: content) {
+		std::string fullpath = path + DIR_DELIM + n.name;
+		if (!RecursiveDelete(fullpath)) {
+			errorstream << "RecursiveDelete: Failed to recurse to "
+					<< fullpath << std::endl;
+			return false;
+		}
+	}
+	infostream << "RecursiveDelete: Deleting directory " << path << std::endl;
+	if (!RemoveDirectory(path.c_str())) {
+		errorstream << "Failed to recursively delete directory "
+				<< path << std::endl;
+		return false;
+	}
 	return true;
 }
 
+bool DeleteSingleFileOrEmptyDirectory(const std::string &path)
+{
+	DWORD attr = GetFileAttributes(path.c_str());
+	bool is_directory = (attr != INVALID_FILE_ATTRIBUTES &&
+			(attr & FILE_ATTRIBUTE_DIRECTORY));
+	if(!is_directory)
+	{
+		bool did = DeleteFile(path.c_str());
+		return did;
+	}
+	else
+	{
+		bool did = RemoveDirectory(path.c_str());
+		return did;
+	}
+}
+
+std::string TempPath()
+{
+	DWORD bufsize = GetTempPath(0, NULL);
+	if(bufsize == 0){
+		errorstream<<"GetTempPath failed, error = "<<GetLastError()<<std::endl;
+		return "";
+	}
+	std::vector<char> buf(bufsize);
+	DWORD len = GetTempPath(bufsize, &buf[0]);
+	if(len == 0 || len > bufsize){
+		errorstream<<"GetTempPath failed, error = "<<GetLastError()<<std::endl;
+		return "";
+	}
+	return std::string(buf.begin(), buf.begin() + len);
+}
+
 #else // POSIX
 
 #include <sys/types.h>
 #include <dirent.h>
-#include <errno.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include <unistd.h>
 
-std::vector<DirListNode> GetDirListing(std::string pathstring)
+std::vector<DirListNode> GetDirListing(const std::string &pathstring)
 {
 	std::vector<DirListNode> listing;
 
-    DIR *dp;
-    struct dirent *dirp;
-    if((dp  = opendir(pathstring.c_str())) == NULL) {
-		//std::cout<<"Error("<<errno<<") opening "<<pathstring<<std::endl;
-        return listing;
-    }
+	DIR *dp;
+	struct dirent *dirp;
+	if((dp = opendir(pathstring.c_str())) == NULL) {
+		//infostream<<"Error("<<errno<<") opening "<<pathstring<<std::endl;
+		return listing;
+	}
 
-    while ((dirp = readdir(dp)) != NULL) {
+	while ((dirp = readdir(dp)) != NULL) {
 		// NOTE:
 		// Be very sure to not include '..' in the results, it will
 		// result in an epic failure when deleting stuff.
-		if(dirp->d_name[0]!='.'){
-			DirListNode node;
-			node.name = dirp->d_name;
-			if(dirp->d_type == DT_DIR) node.dir = true;
-			else node.dir = false;
-			if(node.name != "." && node.name != "..")
-				listing.push_back(node);
+		if(strcmp(dirp->d_name, ".") == 0 || strcmp(dirp->d_name, "..") == 0)
+			continue;
+
+		DirListNode node;
+		node.name = dirp->d_name;
+
+		int isdir = -1; // -1 means unknown
+
+		/*
+			POSIX doesn't define d_type member of struct dirent and
+			certain filesystems on glibc/Linux will only return
+			DT_UNKNOWN for the d_type member.
+
+			Also we don't know whether symlinks are directories or not.
+		*/
+#ifdef _DIRENT_HAVE_D_TYPE
+		if(dirp->d_type != DT_UNKNOWN && dirp->d_type != DT_LNK)
+			isdir = (dirp->d_type == DT_DIR);
+#endif /* _DIRENT_HAVE_D_TYPE */
+
+		/*
+			Was d_type DT_UNKNOWN, DT_LNK or nonexistent?
+			If so, try stat().
+		*/
+		if(isdir == -1) {
+			struct stat statbuf{};
+			if (stat((pathstring + "/" + node.name).c_str(), &statbuf))
+				continue;
+			isdir = ((statbuf.st_mode & S_IFDIR) == S_IFDIR);
 		}
-    }
-    closedir(dp);
+		node.dir = isdir;
+		listing.push_back(node);
+	}
+	closedir(dp);
 
 	return listing;
 }
 
-bool CreateDir(std::string path)
+bool CreateDir(const std::string &path)
 {
 	int r = mkdir(path.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
-	if(r == 0)
-	{
+	if (r == 0) {
 		return true;
 	}
-	else
-	{
-		// If already exists, return true
-		if(errno == EEXIST)
-			return true;
-		return false;
-	}
+
+	// If already exists, return true
+	if (errno == EEXIST)
+		return true;
+	return false;
+
 }
 
-bool PathExists(std::string path)
+bool PathExists(const std::string &path)
 {
-	struct stat st;
+	struct stat st{};
 	return (stat(path.c_str(),&st) == 0);
 }
 
-bool RecursiveDelete(std::string path)
+bool IsPathAbsolute(const std::string &path)
+{
+	return path[0] == '/';
+}
+
+bool IsDir(const std::string &path)
+{
+	struct stat statbuf{};
+	if(stat(path.c_str(), &statbuf))
+		return false; // Actually error; but certainly not a directory
+	return ((statbuf.st_mode & S_IFDIR) == S_IFDIR);
+}
+
+bool IsDirDelimiter(char c)
+{
+	return c == '/';
+}
+
+bool RecursiveDelete(const std::string &path)
 {
 	/*
 		Execute the 'rm' command directly, by fork() and execve()
 	*/
-	
-	std::cerr<<"Removing \""<<path<<"\""<<std::endl;
+
+	infostream<<"Removing \""<<path<<"\""<<std::endl;
 
 	//return false;
-	
+
 	pid_t child_pid = fork();
 
 	if(child_pid == 0)
 	{
 		// Child
 		char argv_data[3][10000];
+#ifdef __ANDROID__
+		strcpy(argv_data[0], "/system/bin/rm");
+#else
 		strcpy(argv_data[0], "/bin/rm");
+#endif
 		strcpy(argv_data[1], "-rf");
-		strncpy(argv_data[2], path.c_str(), 10000);
+		strncpy(argv_data[2], path.c_str(), sizeof(argv_data[2]) - 1);
 		char *argv[4];
 		argv[0] = argv_data[0];
 		argv[1] = argv_data[1];
 		argv[2] = argv_data[2];
 		argv[3] = NULL;
 
-		std::cerr<<"Executing '"<<argv[0]<<"' '"<<argv[1]<<"' '"
+		verbosestream<<"Executing '"<<argv[0]<<"' '"<<argv[1]<<"' '"
 				<<argv[2]<<"'"<<std::endl;
-		
+
 		execv(argv[0], argv);
-		
+
 		// Execv shouldn't return. Failed.
-		return false;
+		_exit(1);
 	}
 	else
 	{
@@ -269,45 +337,417 @@ bool RecursiveDelete(std::string path)
 	}
 }
 
+bool DeleteSingleFileOrEmptyDirectory(const std::string &path)
+{
+	if (IsDir(path)) {
+		bool did = (rmdir(path.c_str()) == 0);
+		if (!did)
+			errorstream << "rmdir errno: " << errno << ": " << strerror(errno)
+					<< std::endl;
+		return did;
+	}
+
+	bool did = (unlink(path.c_str()) == 0);
+	if (!did)
+		errorstream << "unlink errno: " << errno << ": " << strerror(errno)
+				<< std::endl;
+	return did;
+}
+
+std::string TempPath()
+{
+	/*
+		Should the environment variables TMPDIR, TMP and TEMP
+		and the macro P_tmpdir (if defined by stdio.h) be checked
+		before falling back on /tmp?
+
+		Probably not, because this function is intended to be
+		compatible with lua's os.tmpname which under the default
+		configuration hardcodes mkstemp("/tmp/lua_XXXXXX").
+	*/
+#ifdef __ANDROID__
+	return g_settings->get("TMPFolder");
+#else
+	return DIR_DELIM "tmp";
+#endif
+}
+
 #endif
 
-bool RecursiveDeleteContent(std::string path)
+void GetRecursiveDirs(std::vector<std::string> &dirs, const std::string &dir)
+{
+	static const std::set<char> chars_to_ignore = { '_', '.' };
+	if (dir.empty() || !IsDir(dir))
+		return;
+	dirs.push_back(dir);
+	fs::GetRecursiveSubPaths(dir, dirs, false, chars_to_ignore);
+}
+
+std::vector<std::string> GetRecursiveDirs(const std::string &dir)
 {
-	std::cerr<<"Removing content of \""<<path<<"\""<<std::endl;
+	std::vector<std::string> result;
+	GetRecursiveDirs(result, dir);
+	return result;
+}
+
+void GetRecursiveSubPaths(const std::string &path,
+		  std::vector<std::string> &dst,
+		  bool list_files,
+		  const std::set<char> &ignore)
+{
+	std::vector<DirListNode> content = GetDirListing(path);
+	for (const auto &n : content) {
+		std::string fullpath = path + DIR_DELIM + n.name;
+		if (ignore.count(n.name[0]))
+			continue;
+		if (list_files || n.dir)
+			dst.push_back(fullpath);
+		if (n.dir)
+			GetRecursiveSubPaths(fullpath, dst, list_files, ignore);
+	}
+}
+
+bool DeletePaths(const std::vector<std::string> &paths)
+{
+	bool success = true;
+	// Go backwards to succesfully delete the output of GetRecursiveSubPaths
+	for(int i=paths.size()-1; i>=0; i--){
+		const std::string &path = paths[i];
+		bool did = DeleteSingleFileOrEmptyDirectory(path);
+		if(!did){
+			errorstream<<"Failed to delete "<<path<<std::endl;
+			success = false;
+		}
+	}
+	return success;
+}
+
+bool RecursiveDeleteContent(const std::string &path)
+{
+	infostream<<"Removing content of \""<<path<<"\""<<std::endl;
 	std::vector<DirListNode> list = GetDirListing(path);
-	for(unsigned int i=0; i<list.size(); i++)
-	{
-		if(trim(list[i].name) == "." || trim(list[i].name) == "..")
+	for (const DirListNode &dln : list) {
+		if(trim(dln.name) == "." || trim(dln.name) == "..")
 			continue;
-		std::string childpath = path + "/" + list[i].name;
+		std::string childpath = path + DIR_DELIM + dln.name;
 		bool r = RecursiveDelete(childpath);
-		if(r == false)
-		{
-			std::cerr<<"Removing \""<<childpath<<"\" failed"<<std::endl;
+		if(!r) {
+			errorstream << "Removing \"" << childpath << "\" failed" << std::endl;
 			return false;
 		}
 	}
 	return true;
 }
 
-bool CreateAllDirs(std::string path)
+bool CreateAllDirs(const std::string &path)
 {
 
-	size_t pos;
 	std::vector<std::string> tocreate;
 	std::string basepath = path;
 	while(!PathExists(basepath))
 	{
 		tocreate.push_back(basepath);
-		pos = basepath.rfind('/');
-		if(pos == std::string::npos)
-			return false;
-		basepath = basepath.substr(0,pos);
+		basepath = RemoveLastPathComponent(basepath);
+		if(basepath.empty())
+			break;
 	}
 	for(int i=tocreate.size()-1;i>=0;i--)
-		CreateDir(tocreate[i]);
+		if(!CreateDir(tocreate[i]))
+			return false;
+	return true;
+}
+
+bool CopyFileContents(const std::string &source, const std::string &target)
+{
+	FILE *sourcefile = fopen(source.c_str(), "rb");
+	if(sourcefile == NULL){
+		errorstream<<source<<": can't open for reading: "
+			<<strerror(errno)<<std::endl;
+		return false;
+	}
+
+	FILE *targetfile = fopen(target.c_str(), "wb");
+	if(targetfile == NULL){
+		errorstream<<target<<": can't open for writing: "
+			<<strerror(errno)<<std::endl;
+		fclose(sourcefile);
+		return false;
+	}
+
+	size_t total = 0;
+	bool retval = true;
+	bool done = false;
+	char readbuffer[BUFSIZ];
+	while(!done){
+		size_t readbytes = fread(readbuffer, 1,
+				sizeof(readbuffer), sourcefile);
+		total += readbytes;
+		if(ferror(sourcefile)){
+			errorstream<<source<<": IO error: "
+				<<strerror(errno)<<std::endl;
+			retval = false;
+			done = true;
+		}
+		if(readbytes > 0){
+			fwrite(readbuffer, 1, readbytes, targetfile);
+		}
+		if(feof(sourcefile) || ferror(sourcefile)){
+			// flush destination file to catch write errors
+			// (e.g. disk full)
+			fflush(targetfile);
+			done = true;
+		}
+		if(ferror(targetfile)){
+			errorstream<<target<<": IO error: "
+					<<strerror(errno)<<std::endl;
+			retval = false;
+			done = true;
+		}
+	}
+	infostream<<"copied "<<total<<" bytes from "
+		<<source<<" to "<<target<<std::endl;
+	fclose(sourcefile);
+	fclose(targetfile);
+	return retval;
+}
+
+bool CopyDir(const std::string &source, const std::string &target)
+{
+	if(PathExists(source)){
+		if(!PathExists(target)){
+			fs::CreateAllDirs(target);
+		}
+		bool retval = true;
+		std::vector<DirListNode> content = fs::GetDirListing(source);
+
+		for (const auto &dln : content) {
+			std::string sourcechild = source + DIR_DELIM + dln.name;
+			std::string targetchild = target + DIR_DELIM + dln.name;
+			if(dln.dir){
+				if(!fs::CopyDir(sourcechild, targetchild)){
+					retval = false;
+				}
+			}
+			else {
+				if(!fs::CopyFileContents(sourcechild, targetchild)){
+					retval = false;
+				}
+			}
+		}
+		return retval;
+	}
+
+	return false;
+}
+
+bool PathStartsWith(const std::string &path, const std::string &prefix)
+{
+	size_t pathsize = path.size();
+	size_t pathpos = 0;
+	size_t prefixsize = prefix.size();
+	size_t prefixpos = 0;
+	for(;;){
+		bool delim1 = pathpos == pathsize
+			|| IsDirDelimiter(path[pathpos]);
+		bool delim2 = prefixpos == prefixsize
+			|| IsDirDelimiter(prefix[prefixpos]);
+
+		if(delim1 != delim2)
+			return false;
+
+		if(delim1){
+			while(pathpos < pathsize &&
+					IsDirDelimiter(path[pathpos]))
+				++pathpos;
+			while(prefixpos < prefixsize &&
+					IsDirDelimiter(prefix[prefixpos]))
+				++prefixpos;
+			if(prefixpos == prefixsize)
+				return true;
+			if(pathpos == pathsize)
+				return false;
+		}
+		else{
+			size_t len = 0;
+			do{
+				char pathchar = path[pathpos+len];
+				char prefixchar = prefix[prefixpos+len];
+				if(FILESYS_CASE_INSENSITIVE){
+					pathchar = tolower(pathchar);
+					prefixchar = tolower(prefixchar);
+				}
+				if(pathchar != prefixchar)
+					return false;
+				++len;
+			} while(pathpos+len < pathsize
+					&& !IsDirDelimiter(path[pathpos+len])
+					&& prefixpos+len < prefixsize
+					&& !IsDirDelimiter(
+						prefix[prefixpos+len]));
+			pathpos += len;
+			prefixpos += len;
+		}
+	}
+}
+
+std::string RemoveLastPathComponent(const std::string &path,
+		std::string *removed, int count)
+{
+	if(removed)
+		*removed = "";
+
+	size_t remaining = path.size();
+
+	for(int i = 0; i < count; ++i){
+		// strip a dir delimiter
+		while(remaining != 0 && IsDirDelimiter(path[remaining-1]))
+			remaining--;
+		// strip a path component
+		size_t component_end = remaining;
+		while(remaining != 0 && !IsDirDelimiter(path[remaining-1]))
+			remaining--;
+		size_t component_start = remaining;
+		// strip a dir delimiter
+		while(remaining != 0 && IsDirDelimiter(path[remaining-1]))
+			remaining--;
+		if(removed){
+			std::string component = path.substr(component_start,
+					component_end - component_start);
+			if(i)
+				*removed = component + DIR_DELIM + *removed;
+			else
+				*removed = component;
+		}
+	}
+	return path.substr(0, remaining);
+}
+
+std::string RemoveRelativePathComponents(std::string path)
+{
+	size_t pos = path.size();
+	size_t dotdot_count = 0;
+	while (pos != 0) {
+		size_t component_with_delim_end = pos;
+		// skip a dir delimiter
+		while (pos != 0 && IsDirDelimiter(path[pos-1]))
+			pos--;
+		// strip a path component
+		size_t component_end = pos;
+		while (pos != 0 && !IsDirDelimiter(path[pos-1]))
+			pos--;
+		size_t component_start = pos;
+
+		std::string component = path.substr(component_start,
+				component_end - component_start);
+		bool remove_this_component = false;
+		if (component == ".") {
+			remove_this_component = true;
+		} else if (component == "..") {
+			remove_this_component = true;
+			dotdot_count += 1;
+		} else if (dotdot_count != 0) {
+			remove_this_component = true;
+			dotdot_count -= 1;
+		}
+
+		if (remove_this_component) {
+			while (pos != 0 && IsDirDelimiter(path[pos-1]))
+				pos--;
+			if (component_start == 0) {
+				// We need to remove the delemiter too
+				path = path.substr(component_with_delim_end, std::string::npos);
+			} else {
+				path = path.substr(0, pos) + DIR_DELIM +
+					path.substr(component_with_delim_end, std::string::npos);
+			}
+			if (pos > 0)
+				pos++;
+		}
+	}
+
+	if (dotdot_count > 0)
+		return "";
+
+	// remove trailing dir delimiters
+	pos = path.size();
+	while (pos != 0 && IsDirDelimiter(path[pos-1]))
+		pos--;
+	return path.substr(0, pos);
+}
+
+std::string AbsolutePath(const std::string &path)
+{
+#ifdef _WIN32
+	char *abs_path = _fullpath(NULL, path.c_str(), MAX_PATH);
+#else
+	char *abs_path = realpath(path.c_str(), NULL);
+#endif
+	if (!abs_path) return "";
+	std::string abs_path_str(abs_path);
+	free(abs_path);
+	return abs_path_str;
+}
+
+const char *GetFilenameFromPath(const char *path)
+{
+	const char *filename = strrchr(path, DIR_DELIM_CHAR);
+	return filename ? filename + 1 : path;
+}
+
+bool safeWriteToFile(const std::string &path, const std::string &content)
+{
+	std::string tmp_file = path + ".~mt";
+
+	// Write to a tmp file
+	std::ofstream os(tmp_file.c_str(), std::ios::binary);
+	if (!os.good())
+		return false;
+	os << content;
+	os.flush();
+	os.close();
+	if (os.fail()) {
+		// Remove the temporary file because writing it failed and it's useless.
+		remove(tmp_file.c_str());
+		return false;
+	}
+
+	bool rename_success = false;
+
+	// Move the finished temporary file over the real file
+#ifdef _WIN32
+	// When creating the file, it can cause Windows Search indexer, virus scanners and other apps
+	// to query the file. This can make the move file call below fail.
+	// We retry up to 5 times, with a 1ms sleep between, before we consider the whole operation failed
+	int number_attempts = 0;
+	while (number_attempts < 5) {
+		rename_success = MoveFileEx(tmp_file.c_str(), path.c_str(),
+				MOVEFILE_REPLACE_EXISTING | MOVEFILE_WRITE_THROUGH);
+		if (rename_success)
+			break;
+		sleep_ms(1);
+		++number_attempts;
+	}
+#else
+	// On POSIX compliant systems rename() is specified to be able to swap the
+	// file in place of the destination file, making this a truly error-proof
+	// transaction.
+	rename_success = rename(tmp_file.c_str(), path.c_str()) == 0;
+#endif
+	if (!rename_success) {
+		warningstream << "Failed to write to file: " << path.c_str() << std::endl;
+		// Remove the temporary file because moving it over the target file
+		// failed.
+		remove(tmp_file.c_str());
+		return false;
+	}
+
 	return true;
 }
 
+bool Rename(const std::string &from, const std::string &to)
+{
+	return rename(from.c_str(), to.c_str()) == 0;
+}
+
 } // namespace fs