FileOperations.cc

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#ifdef  _WIN32
#ifndef _WIN32_IE
#define _WIN32_IE 0x0500        // For SHGetSpecialFolderPathW with MinGW
#endif
#include "utf8_checked.hh"
#include <windows.h>
#include <shlobj.h>
#include <shellapi.h>
#include <io.h>
#include <direct.h>
#include <ctype.h>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#else // ifdef _WIN32_ ...
#include <sys/types.h>
#include <pwd.h>
#include <climits>
#include <unistd.h>
#endif // ifdef _WIN32_ ... else ...
 
#include "openmsx.hh" // for ad_printf
 
#include "systemfuncs.hh"
 
#if HAVE_NFTW
#include <ftw.h>
#endif
 
#if defined(PATH_MAX)
#define MAXPATHLEN PATH_MAX
#elif defined(MAX_PATH)
#define MAXPATHLEN MAX_PATH
#else
#define MAXPATHLEN 4096
#endif
 
 
#ifdef __APPLE__
#include "FileOperationsMac.hh"
#endif
 
#include "ReadDir.hh"
#include "FileOperations.hh"
#include "FileException.hh"
#include "StringOp.hh"
#include "unistdp.hh"
#include "one_of.hh"
#include "ranges.hh"
#include "strCat.hh"
#include "build-info.hh"
#include <algorithm>
#include <array>
#include <sstream>
#include <cerrno>
#include <cstdlib>
#include <stdexcept>
#include <cassert>
#include <iterator>
 
#ifndef _MSC_VER
#include <dirent.h>
#endif
 
#if PLATFORM_ANDROID
#include "SDL_system.h" // for GetExternalStorage stuff
#endif
 
using std::string;
using std::string_view;
 
#ifdef _WIN32
using namespace utf8;
#endif
 
namespace openmsx::FileOperations {
 
bool needsTildeExpansion(std::string_view path)
{
        return !path.empty() && (path[0] == '~');
}
 
string expandTilde(string path)
{
        if (!needsTildeExpansion(path)) {
                return path;
        }
        auto pos = path.find_first_of('/');
        string_view user = ((path.size() == 1) || (pos == 1))
                        ? string_view{}
                        : string_view(path).substr(1, (pos == string::npos) ? pos : pos - 1);
        string result = getUserHomeDir(user);
        if (result.empty()) {
                // failed to find homedir, return the path unchanged
                return path;
        }
        if (pos == string_view::npos) {
                return result;
        }
        if (result.back() != '/') {
                result += '/';
        }
        string_view last = string_view(path).substr(pos + 1);
        result.append(last.data(), last.size());
        return result;
}
 
void mkdir(zstring_view path, mode_t mode)
{
#ifdef _WIN32
        (void)&mode; // Suppress C4100 VC++ warning
        if ((path == "/") || path.ends_with(':') || path.ends_with(":/")) {
                return;
        }
        int result = _wmkdir(utf8to16(getNativePath(string(path))).c_str());
#else
        int result = ::mkdir(path.c_str(), mode);
#endif
        if (result && (errno != EEXIST)) {
                throw FileException("Error creating dir ", path);
        }
}
 
static bool isUNCPath(string_view path)
{
#ifdef _WIN32
        return path.starts_with("//") || path.starts_with("\\\\");
#else
        (void)path;
        return false;
#endif
}
 
void mkdirp(string path)
{
        if (path.empty()) {
                return;
        }
 
        // We may receive platform-specific paths here, so conventionalize early
        path = getConventionalPath(std::move(path));
 
        // If the directory already exists, don't try to recreate it
        if (isDirectory(path))
                return;
 
        // If the path is a UNC path (e.g. \\server\share) then the first two paths in the loop below will be \ and \\server
        // If the path is an absolute path (e.g. c:\foo\bar) then the first path in the loop will be C:
        // None of those are valid directory paths, so we skip over them and don't call mkdir.
        // Relative paths are fine, since each segment in the path is significant.
        int skip = isUNCPath(path) ? 2 :
                   isAbsolutePath(path) ? 1 : 0;
        string::size_type pos = 0;
        do {
                pos = path.find_first_of('/', pos + 1);
                if (skip) {
                        skip--;
                        continue;
                }
                mkdir(path.substr(0, pos), 0755);
        } while (pos != string::npos);
 
        if (!isDirectory(path)) {
                throw FileException("Error creating dir ", path);
        }
}
 
int unlink(zstring_view path)
{
#ifdef _WIN32
        return _wunlink(utf8to16(path).c_str());
#else
        return ::unlink(path.c_str());
#endif
}
 
int rmdir(zstring_view path)
{
#ifdef _WIN32
        return _wrmdir(utf8to16(path).c_str());
#else
        return ::rmdir(path.c_str());
#endif
}
 
#ifdef _WIN32
int deleteRecursive(zstring_view path)
{
        std::wstring pathW = utf8to16(path);
 
        SHFILEOPSTRUCTW rmdirFileOp;
        rmdirFileOp.hwnd = nullptr;
        rmdirFileOp.wFunc = FO_DELETE;
        rmdirFileOp.pFrom = pathW.c_str();
        rmdirFileOp.pTo = nullptr;
        rmdirFileOp.fFlags = FOF_SILENT | FOF_NOCONFIRMATION | FOF_NOERRORUI;
        rmdirFileOp.fAnyOperationsAborted = FALSE;
        rmdirFileOp.hNameMappings = nullptr;
        rmdirFileOp.lpszProgressTitle = nullptr;
 
        return SHFileOperationW(&rmdirFileOp);
}
#elif HAVE_NFTW
static int deleteRecursive_cb(const char* fpath, const struct stat* /*sb*/,
                              int /*typeflag*/, struct FTW* /*ftwbuf*/)
{
        return remove(fpath);
}
int deleteRecursive(zstring_view path)
{
        return nftw(path.c_str(), deleteRecursive_cb, 64, FTW_DEPTH | FTW_PHYS);
}
#else
// This is a platform independent version of deleteRecursive() (it builds on
// top of helper routines that _are_ platform specific). Though I still prefer
// the two platform specific deleteRecursive() routines above because they are
// likely more optimized and likely contain less bugs than this version (e.g.
// we're walking over the entries in a directory while simultaneously deleting
// entries in that same directory. Although this seems to work fine, I'm not
// 100% sure our ReadDir 'emulation code' for windows covers all corner cases.
// While the windows version above very likely does handle everything).
int deleteRecursive(const std::string& path)
{
        if (isDirectory(path)) {
                {
                        ReadDir dir(path);
                        while (dirent* d = dir.getEntry()) {
                                int err = deleteRecursive(d->d_name);
                                if (err) return err;
                        }
                }
                return rmdir(path);
        } else {
                return unlink(path);
        }
}
#endif
 
FILE_t openFile(zstring_view filename, zstring_view mode)
{
        // Mode must contain a 'b' character. On unix this doesn't make any
        // difference. But on windows this is required to open the file
        // in binary mode.
        assert(mode.find('b') != std::string::npos);
#ifdef _WIN32
        return FILE_t(_wfopen(utf8to16(filename).c_str(),
                              utf8to16(mode).c_str()));
#else
        return FILE_t(fopen(filename.c_str(), mode.c_str()));
#endif
}
 
void openOfStream(std::ofstream& stream, zstring_view filename)
{
#if defined _WIN32 && defined _MSC_VER
        // MinGW 3.x doesn't support ofstream.open(wchar_t*)
        // TODO - this means that unicode text may not work right here
        stream.open(utf8to16(filename).c_str());
#else
        stream.open(filename.c_str());
#endif
}
 
void openOfStream(std::ofstream& stream, zstring_view filename,
                  std::ios_base::openmode mode)
{
#if defined _WIN32 && defined _MSC_VER
        // MinGW 3.x doesn't support ofstream.open(wchar_t*)
        // TODO - this means that unicode text may not work right here
        stream.open(utf8to16(filename).c_str(), mode);
#else
        stream.open(filename.c_str(), mode);
#endif
}
 
string_view getFilename(string_view path)
{
        if (auto pos = path.rfind('/'); pos != string_view::npos) {
                return path.substr(pos + 1);
        }
        return path;
}
 
string_view getDirName(string_view path)
{
        if (auto pos = path.rfind('/'); pos != string_view::npos) {
                return path.substr(0, pos + 1);
        }
        return {};
}
 
string_view getExtension(string_view path)
{
        string_view filename = getFilename(path);
        if (auto pos = filename.rfind('.'); pos != string_view::npos) {
                return filename.substr(pos);
        }
        return {};
}
 
string_view stripExtension(string_view path)
{
        if (auto pos = path.rfind('.'); pos != string_view::npos) {
                return path.substr(0, pos);
        }
        return path;
}
 
string join(string_view part1, string_view part2)
{
        if (part1.empty() || isAbsolutePath(part2)) {
                return string(part2);
        }
        if (part1.back() == '/') {
                return strCat(part1, part2);
        }
        return strCat(part1, '/', part2);
}
string join(string_view part1, string_view part2, string_view part3)
{
        return join(part1, join(part2, part3));
}
 
string join(string_view part1, string_view part2,
            string_view part3, string_view part4)
{
        return join(part1, join(part2, join(part3, part4)));
}
 
#ifdef _WIN32
string getNativePath(string path)
{
        ranges::replace(path, '/', '\\');
        return path;
}
 
string getConventionalPath(string path)
{
        ranges::replace(path, '\\', '/');
        return path;
}
#endif
 
string getCurrentWorkingDirectory()
{
#ifdef _WIN32
        std::array<wchar_t, MAXPATHLEN> bufW;
        const wchar_t* result = _wgetcwd(bufW.data(), bufW.size());
        if (!result) {
                throw FileException("Couldn't get current working directory.");
        }
        return utf16to8(result);
#else
        std::array<char, MAXPATHLEN> buf;
        char* result = getcwd(buf.data(), buf.size());
        if (!result) {
                throw FileException("Couldn't get current working directory.");
        }
        return buf.data();
#endif
}
 
string getAbsolutePath(string_view path)
{
        // In rare cases getCurrentWorkingDirectory() can throw,
        // so only call it when really necessary.
        if (isAbsolutePath(path)) {
                return string(path);
        }
        return join(getCurrentWorkingDirectory(), path);
}
 
bool isAbsolutePath(string_view path)
{
        if (isUNCPath(path)) return true;
#ifdef _WIN32
        if ((path.size() >= 3) && (path[1] == ':') && (path[2] == one_of('/', '\\'))) {
                char drive = tolower(path[0]);
                if (('a' <= drive) && (drive <= 'z')) {
                        return true;
                }
        }
#endif
        return !path.empty() && (path[0] == '/');
}
 
string getUserHomeDir(string_view username)
{
#ifdef _WIN32
        (void)(&username); // ignore parameter, avoid warning
 
        std::array<wchar_t, MAXPATHLEN + 1> bufW;
        if (!SHGetSpecialFolderPathW(nullptr, bufW.data(), CSIDL_PERSONAL, TRUE)) {
                throw FatalError(
                        "SHGetSpecialFolderPathW failed: ", GetLastError());
        }
 
        return getConventionalPath(utf16to8(bufW.data()));
#else
        const char* dir = nullptr;
        struct passwd* pw = nullptr;
        if (username.empty()) {
                dir = getenv("HOME");
                if (!dir) {
                        pw = getpwuid(getuid());
                }
        } else {
                pw = getpwnam(string(username).c_str());
        }
        if (pw) {
                dir = pw->pw_dir;
        }
        return dir ? dir : string{};
#endif
}
 
const string& getUserOpenMSXDir()
{
        static const string OPENMSX_DIR = []() -> string {
                if (const char* home = getenv("OPENMSX_HOME")) {
                        return home;
                }
#ifdef _WIN32
                return expandTilde("~/openMSX");
#elif PLATFORM_ANDROID
                // TODO: do something to query whether the storage is available
                // via SDL_AndroidGetExternalStorageState
                return strCat(SDL_AndroidGetExternalStoragePath(), "/openMSX");
#else
                return expandTilde("~/.openMSX");
#endif
        }();
        return OPENMSX_DIR;
}
 
const string& getUserDataDir()
{
        static std::optional<string> result;
        if (!result) {
                const char* const NAME = "OPENMSX_USER_DATA";
                const char* value = getenv(NAME);
                result = value ? value : getUserOpenMSXDir() + "/share";
        }
        return *result;
}
 
const string& getSystemDataDir()
{
        static std::optional<string> result;
        if (!result) result = []() -> string {
                if (const char* value = getenv("OPENMSX_SYSTEM_DATA")) {
                        return value;
                }
#ifdef _WIN32
                std::array<wchar_t, MAXPATHLEN + 1> bufW;
                if (int res = GetModuleFileNameW(nullptr, bufW.data(), DWORD(bufW.size()));
                    !res) {
                        throw FatalError(
                                "Cannot detect openMSX directory. GetModuleFileNameW failed: ",
                                GetLastError());
                }
 
                string filename = utf16to8(bufW.data());
                auto pos = filename.find_last_of('\\');
                if (pos == string::npos) {
                        throw FatalError("openMSX is not in directory!?");
                }
                return getConventionalPath(filename.substr(0, pos)) + "/share";
#elif defined(__APPLE__)
                return findResourceDir("share");
#elif PLATFORM_ANDROID
                return getAbsolutePath("openmsx_system");
#else
                // defined in build-info.hh (default /opt/openMSX/share)
                return DATADIR;
#endif
        }();
        return *result;
}
 
const string& getSystemDocDir()
{
        static std::optional<string> result;
        if (!result) result = []() -> string {
#ifdef _WIN32
                std::array<wchar_t, MAXPATHLEN + 1> bufW;
                if (int res = GetModuleFileNameW(nullptr, bufW.data(), DWORD(bufW.size()));
                    !res) {
                        throw FatalError(
                                "Cannot detect openMSX directory. GetModuleFileNameW failed: ",
                                GetLastError());
                }
 
                string filename = utf16to8(bufW.data());
                auto pos = filename.find_last_of('\\');
                if (pos == string::npos) {
                        throw FatalError("openMSX is not in directory!?");
                }
                return getConventionalPath(filename.substr(0, pos)) + "/doc";
#elif defined(__APPLE__)
                return findResourceDir("doc");
#elif PLATFORM_ANDROID
                return getAbsolutePath("openmsx_system"); // TODO: currently no docs are installed on Android
#else
                // defined in build-info.hh (default /opt/openMSX/doc)
                return DOCDIR;
#endif
        }();
        return *result;
}
 
#ifdef _WIN32
static bool driveExists(char driveLetter)
{
        std::array<char, 3> buf = {driveLetter, ':', 0};
        return GetFileAttributesA(buf.data()) != INVALID_FILE_ATTRIBUTES;
}
#endif
 
#ifdef _WIN32
string expandCurrentDirFromDrive(string path)
{
        string result = path;
        if (((path.size() == 2) && (path[1] == ':')) ||
                ((path.size() >= 3) && (path[1] == ':') && (path[2] != '/'))) {
                // get current directory for this drive
                unsigned char drive = tolower(path[0]);
                if (('a' <= drive) && (drive <= 'z')) {
                        std::array<wchar_t, MAXPATHLEN + 1> bufW;
                        if (driveExists(drive) &&
                                _wgetdcwd(drive - 'a' + 1, bufW.data(), MAXPATHLEN)) {
                                result = getConventionalPath(utf16to8(bufW.data()));
                                if (result.back() != '/') {
                                        result += '/';
                                }
                                if (path.size() > 2) {
                                        auto tmp = std::string_view(path).substr(2);
                                        result.append(tmp.data(), tmp.size());
                                }
                        }
                }
        }
        return result;
}
#endif
 
std::optional<Stat> getStat(zstring_view filename)
{
        std::optional<Stat> st;
        st.emplace(); // allocate relatively large 'struct stat' in the return slot
 
#ifdef _WIN32
        std::string filename2(filename);
        // workaround for VC++: strip trailing slashes (but keep it if it's the
        // only character in the path)
        if (auto pos = filename2.find_last_not_of('/'); pos != string::npos) {
                filename2.resize(pos + 1);
        } else {
                // string was either empty or a (sequence of) '/' character(s)
                if (!filename2.empty()) filename2.resize(1);
        }
        if (_wstat(utf8to16(filename2).c_str(), &*st)) {
                st.reset();
        }
#else
        if (stat(filename.c_str(), &*st)) {
                st.reset();
        }
#endif
 
        return st; // we count on NRVO to eliminate memcpy of 'struct stat'
}
 
bool isRegularFile(const Stat& st)
{
        return S_ISREG(st.st_mode);
}
bool isRegularFile(zstring_view filename)
{
        auto st = getStat(filename);
        return st && isRegularFile(*st);
}
 
bool isDirectory(const Stat& st)
{
        return S_ISDIR(st.st_mode);
}
 
bool isDirectory(zstring_view directory)
{
        auto st = getStat(directory);
        return st && isDirectory(*st);
}
 
bool exists(zstring_view filename)
{
        return static_cast<bool>(getStat(filename));
}
 
static unsigned getNextNum(const dirent* d, string_view prefix, string_view extension,
                           unsigned nofDigits)
{
        auto extensionLen = extension.size();
        auto prefixLen = prefix.size();
        string_view name(d->d_name);
 
        if ((name.size() != (prefixLen + nofDigits + extensionLen)) ||
            (!name.starts_with(prefix)) ||
            (name.substr(prefixLen + nofDigits, extensionLen) != extension)) {
                return 0;
        }
        return StringOp::stringToBase<10, unsigned>(name.substr(prefixLen, nofDigits)).value_or(0);
}
 
string getNextNumberedFileName(
        string_view directory, string_view prefix, string_view extension, bool addSeparator)
{
        std::string newPrefix;
        if (addSeparator) {
                newPrefix = strCat(prefix, ((prefix.find(' ') != std::string_view::npos) ? ' ' : '_'));
                prefix = newPrefix;
        }
 
        const unsigned nofDigits = 4;
 
        unsigned max_num = 0;
 
        string dirName = join(getUserOpenMSXDir(), directory);
        try {
                mkdirp(dirName);
        } catch (FileException&) {
                // ignore
        }
 
        ReadDir dir(dirName);
        while (auto* d = dir.getEntry()) {
                max_num = std::max(max_num, getNextNum(d, prefix, extension, nofDigits));
        }
 
        std::ostringstream os;
        os << FileOperations::join(dirName, prefix);
        os.width(nofDigits);
        os.fill('0');
        os << (max_num + 1) << extension;
        return os.str();
}
 
string parseCommandFileArgument(
        string_view argument, string_view directory,
        string_view prefix,   string_view extension)
{
        if (argument.empty()) {
                // directory is also created when needed
                return getNextNumberedFileName(directory, prefix, extension);
        }
 
        string filename(argument);
        if (getDirName(filename).empty()) {
                // no dir given, use standard dir (and create it)
                string dir = strCat(getUserOpenMSXDir(), '/', directory);
                mkdirp(dir);
                filename = strCat(dir, '/', filename);
        } else {
                filename = expandTilde(std::move(filename));
        }
 
        if (!filename.ends_with(extension) && !exists(filename)) {
                // Expected extension not already given, append it. But only
                // when the filename without extension doesn't already exist.
                // Without this exception stuff like 'soundlog start /dev/null'
                // reports an error " ... error opening file /dev/null.wav."
                filename.append(extension.data(), extension.size());
        }
        return filename;
}
 
string getTempDir()
{
#ifdef _WIN32
        if (DWORD len = GetTempPathW(0, nullptr)) {
                std::wstring bufW(len, L'\0'); // TODO use c++23 resize_and_overwrite()
                if (int len2 = GetTempPathW(len, bufW.data())) {
                        bufW.resize(len2);
                        // Strip last backslash
                        if (bufW.ends_with(L'\\')) {
                                bufW.pop_back();
                        }
                        return utf16to8(bufW);
                }
        }
        throw FatalError("GetTempPathW failed: ", GetLastError());
#elif PLATFORM_ANDROID
        string result = getSystemDataDir() + "/tmp";
        return result;
#else
        const char* result = nullptr;
        if (!result) result = getenv("TMPDIR");
        if (!result) result = getenv("TMP");
        if (!result) result = getenv("TEMP");
        if (!result) {
                result = "/tmp";
        }
        return result;
#endif
}
 
FILE_t openUniqueFile(const std::string& directory, std::string& filename)
{
#ifdef _WIN32
        std::wstring directoryW = utf8to16(directory);
        std::array<wchar_t, MAX_PATH> filenameW;
        if (!GetTempFileNameW(directoryW.c_str(), L"msx", 0, filenameW.data())) {
                throw FileException("GetTempFileNameW failed: ", GetLastError());
        }
        filename = utf16to8(filenameW.data());
        return FILE_t(_wfopen(filenameW.data(), L"wb"));
#else
        filename = directory + "/XXXXXX";
        auto oldMask = umask(S_IRWXO | S_IRWXG);
        int fd = mkstemp(const_cast<char*>(filename.c_str()));
        umask(oldMask);
        if (fd == -1) {
                throw FileException("Couldnt get temp file name");
        }
        return FILE_t(fdopen(fd, "wb"));
#endif
}
 
} // namespace openmsx::FileOperations