文件相关

1.字符串分割　

vector<string> smallby_split(string str,string pattern){
    string::size_type pos;
    vector<string> vec;
    str += pattern;     //可匹配最后的字符
    int size = str.size();
    if(pattern == ""){
        vec.push_back(str);
        return vec;
    }
    for(int i=0; i<size; ++i){
        pos = str.find(pattern,i);
        if(pos<size){
            vec.push_back(str.substr(i,pos-i));
            i = pos + pattern.size(); 
            i -= 1;        //要执行++i
        }
    }
    return vec;
}