C++ StringA::FindLast方法代码示例

/*
 * vislib::sys::Path::MakeDirectory
 */
void vislib::sys::Path::MakeDirectory(const StringA& path) {
    Stack<StringA> missingParts;
    StringA firstBuilt;
    StringA curPath = Resolve(path);

    while (!File::Exists(curPath)) {
        StringA::Size pos = curPath.FindLast(SEPARATOR_A);
        if (pos != StringA::INVALID_POS) {
            missingParts.Push(curPath.Substring(pos + 1));
            if (missingParts.Peek()->IsEmpty()) {
                // Remove empty directories as the incremental directory 
                // creation later on will fail for these.
                missingParts.Pop();
            }
            curPath.Truncate(pos);

        } else {
            // Problem: No Separators left, but directory still does not exist.
#ifdef _WIN32
            throw vislib::sys::SystemException(ERROR_INVALID_NAME, __FILE__, __LINE__);
#else /* _WIN32 */
            throw vislib::sys::SystemException(EINVAL, __FILE__, __LINE__);
#endif /* _WIN32 */
        }
    }

    // curPath exists
    if (!File::IsDirectory(curPath)) {
        // the latest existing directory is not a directory (may be a file?)
#ifdef _WIN32
        throw vislib::sys::SystemException(ERROR_DIRECTORY, __FILE__, __LINE__);
#else /* _WIN32 */
        throw vislib::sys::SystemException(EEXIST, __FILE__, __LINE__);
#endif /* _WIN32 */
    }

    while (!missingParts.IsEmpty()) {
        curPath += SEPARATOR_A;
        curPath += missingParts.Pop();

#ifdef _WIN32
        if (CreateDirectoryA(curPath, NULL) != 0) {
#else /* _WIN32 */
        if (mkdir(curPath, S_IRWXG | S_IRWXO | S_IRWXU) == 0) { // TODO: Check
#endif /* _WIN32 */
            // success, so go on.
            if (firstBuilt.IsEmpty()) {
                firstBuilt = curPath;
            }

        } else {
            DWORD errorCode = GetLastError();

            try {
                // failure, so try to remove already created paths and throw exception.
                DeleteDirectory(firstBuilt, true);
            } catch(...) {
            }

            throw vislib::sys::SystemException(errorCode, __FILE__, __LINE__);
        }
    }
    // we are done!
}


/*
 * vislib::sys::Path::MakeDirectory
 */
void vislib::sys::Path::MakeDirectory(const StringW& path) {
#ifdef _WIN32
    Stack<StringW> missingParts;
    StringW firstBuilt;
    StringW curPath = Resolve(path);

    while (!File::Exists(curPath)) {
        StringW::Size pos = curPath.FindLast(SEPARATOR_W);
        if (pos != StringW::INVALID_POS) {
            missingParts.Push(curPath.Substring(pos + 1));
            if (missingParts.Peek()->IsEmpty()) {
                // Remove empty directories as the incremental directory 
                // creation later on will fail for these.
                missingParts.Pop();
            }
            curPath.Truncate(pos);

        } else {
            // Problem: No Separators left, but directory still does not exist.
            throw vislib::sys::SystemException(ERROR_INVALID_NAME, __FILE__, __LINE__);
        }
    }

    // curPath exists
    if (!File::IsDirectory(curPath)) {
        // the latest existing directory is not a directory (may be a file?)
        throw vislib::sys::SystemException(ERROR_DIRECTORY, __FILE__, __LINE__);
    }
//.........这里部分代码省略.........

/*
 * vislib::sys::Path::Canonicalise
 */
vislib::StringA vislib::sys::Path::Canonicalise(const StringA& path) {
    const StringA DOUBLE_SEPARATOR(Path::SEPARATOR_A, 2);

#ifdef _WIN32
    StringA retval;

    if (::PathCanonicalizeA(retval.AllocateBuffer(MAX_PATH), path) != TRUE) {
        throw SystemException(__FILE__, __LINE__);
    }

    retval.Replace(DOUBLE_SEPARATOR.PeekBuffer(), SEPARATOR_A);
    retval.Replace(DOUBLE_SEPARATOR.PeekBuffer(), SEPARATOR_A);

    /* Ensure that a UNC path remains a UNC path. */
    if (path.StartsWith(DOUBLE_SEPARATOR)) {
        // Note: Double separator replacement above leaves at least one 
        // separator, so we must only prepend one additional one.
        retval.Prepend(SEPARATOR_A);
    }

    return retval;

#else /* _WIN32 */
    const char *BACK_REF = "/..";
    const char *CUR_REF = "/.";             // Note: "./" does not work
    StringA::Size BACK_REF_LEN = ::strlen(BACK_REF);
    StringA::Size bwRefPos = 0;             // Position of back reference.
    StringA::Size remDirPos = 0;            // Position of directory to erase.
    StringA retval(path);
    

    /* Remove backward references, first. */
    while ((bwRefPos = retval.Find(BACK_REF)) != StringA::INVALID_POS) {

        if ((bwRefPos > 0) 
                && (remDirPos = retval.FindLast(SEPARATOR_A, bwRefPos - 1))
                != StringA::INVALID_POS) {
            /* Found inner backward reference, so remove some parts. */
            retval.Remove(remDirPos, bwRefPos - remDirPos + BACK_REF_LEN);

        } else {
            /* 
             * No other path separator is before this one, so we can remove
             * everything before 'bwRefPos'.
             */
            retval.Remove(0, bwRefPos + BACK_REF_LEN);
        }
    }

    /*
     * Remove references to the current directory. This must be done after
     * removing backward references.
     */
    retval.Remove(CUR_REF);
    
    /* Remove odd and even number of repeated path separators. */
    retval.Replace(DOUBLE_SEPARATOR.PeekBuffer(), SEPARATOR_A);
    retval.Replace(DOUBLE_SEPARATOR.PeekBuffer(), SEPARATOR_A);

    return retval;
#endif /* _WIN32 */
}