cpp string demos.cpp

/* remove non-alphabet from head and tail */

int main() 
{
    const char* alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    string text;
    while (cin >> text) {
        string::size_type begin = text.find_first_of(alphabet);
        string::size_type end = text.find_last_of(alphabet) + 1;
        text = text.substr(begin, end - begin);
        cout << text << endl;
    }
    return 0;
}

int _tmain(int argc, _TCHAR* argv[])
{
    std::string str = " //*---Hello Word!......------";
    auto begin = find_if(str.begin(), str.end(), isalpha);
    auto end = find_if(str.rbegin(), str.rend(), isalpha);
    
    str = str.substr(distance(str.begin(), begin), distance(begin, end.base()));
    cout << str << endl;
    getchar();
    return 0;
}

/* user-defined string split */

void SplitString(const string& str, vector<string>* tokens)
{
    const char* delim = " |,";
    string::size_type begin = 0, end;

    while ((begin = str.find_first_not_of(delim, begin)) != string::npos) {
        end = str.find_first_of(delim, begin);
        if (end == string::npos)
            end = str.length();
        tokens->push_back(str.substr(begin, end - begin));
        begin = end + 1;
    }
}

void SplitString(const string& str, char delim, vector<string>* tokens)
{
    std::stringstream ss(str);
    string item;
    while (std::getline(ss, item, delim)) {
        tokens->push_back(item);
    }
}

int GetLine(const char* buf, size_t offset, size_t bufSize, string* line)
{
    int processedCnt = 0;
    size_t i;
    for (i = offset; i < bufSize; ++i) {
        ++processedCnt;
        if (buf[i] == '\n' || buf[i] == '\0') {
            break;
        } else if (buf[i] == '\r') {
            ++processedCnt;
            break;
        }
    }

    line->assign(&buf[offset], &buf[i]);
    return processedCnt;
}

void StringReplace(string* src, const string& str, const string& rewritten)
{
    string::size_type pos = 0;

    while ((pos = src->find(str, pos)) != string::npos) {
        src->replace(pos, str.length(), rewritten);
        pos += rewritten.length();
    }
}