Boost有很强的拆分功能:Boost::algorithm::split。

示例程序:

#include <vector>
#include <boost/algorithm/string.hpp>

int main() {
    auto s = "a,b, c ,,e,f,";
    std::vector<std::string> fields;
    boost::split(fields, s, boost::is_any_of(","));
    for (const auto& field : fields)
        std::cout << "\"" << field << "\"\n";
    return 0;
}

输出:

"a"
"b"
" c "
""
"e"
"f"
""

这是一个简单的循环，只对标准库文件进行标记

#include <iostream.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <conio.h>
class word
    {
     public:
     char w[20];
     word()
      {
        for(int j=0;j<=20;j++)
        {w[j]='\0';
      }
   }



};

void main()
  {
    int i=1,n=0,j=0,k=0,m=1;
    char input[100];
    word ww[100];
    gets(input);

    n=strlen(input);


    for(i=0;i<=m;i++)
      {
        if(context[i]!=' ')
         {
            ww[k].w[j]=context[i];
            j++;

         }
         else
        {
         k++;
         j=0;
         m++;
        }

   }
 }

我以前只用标准库做了一个lexer/tokenizer。代码如下:

#include <iostream>
#include <string>
#include <vector>
#include <sstream>

using namespace std;

string seps(string& s) {
    if (!s.size()) return "";
    stringstream ss;
    ss << s[0];
    for (int i = 1; i < s.size(); i++) {
        ss << '|' << s[i];
    }
    return ss.str();
}

void Tokenize(string& str, vector<string>& tokens, const string& delimiters = " ")
{
    seps(str);

    // Skip delimiters at beginning.
    string::size_type lastPos = str.find_first_not_of(delimiters, 0);
    // Find first "non-delimiter".
    string::size_type pos = str.find_first_of(delimiters, lastPos);

    while (string::npos != pos || string::npos != lastPos)
    {
        // Found a token, add it to the vector.
        tokens.push_back(str.substr(lastPos, pos - lastPos));
        // Skip delimiters.  Note the "not_of"
        lastPos = str.find_first_not_of(delimiters, pos);
        // Find next "non-delimiter"
        pos = str.find_first_of(delimiters, lastPos);
    }
}

int main(int argc, char *argv[])
{
    vector<string> t;
    string s = "Tokens for everyone!";

    Tokenize(s, t, "|");

    for (auto c : t)
        cout << c << endl;

    system("pause");

    return 0;
}

Boost标记器类可以使这类事情变得非常简单:

#include <iostream>
#include <string>
#include <boost/foreach.hpp>
#include <boost/tokenizer.hpp>

using namespace std;
using namespace boost;

int main(int, char**)
{
    string text = "token, test   string";

    char_separator<char> sep(", ");
    tokenizer< char_separator<char> > tokens(text, sep);
    BOOST_FOREACH (const string& t, tokens) {
        cout << t << "." << endl;
    }
}

针对c++ 11更新:

#include <iostream>
#include <string>
#include <boost/tokenizer.hpp>

using namespace std;
using namespace boost;

int main(int, char**)
{
    string text = "token, test   string";

    char_separator<char> sep(", ");
    tokenizer<char_separator<char>> tokens(text, sep);
    for (const auto& t : tokens) {
        cout << t << "." << endl;
    }
}

这里有许多过于复杂的建议。试试这个简单的std::string解决方案:

using namespace std;

string someText = ...

string::size_type tokenOff = 0, sepOff = tokenOff;
while (sepOff != string::npos)
{
    sepOff = someText.find(' ', sepOff);
    string::size_type tokenLen = (sepOff == string::npos) ? sepOff : sepOff++ - tokenOff;
    string token = someText.substr(tokenOff, tokenLen);
    if (!token.empty())
        /* do something with token */;
    tokenOff = sepOff;
}

MFC/ATL有一个非常好的标记器。从MSDN:

CAtlString str( "%First Second#Third" );
CAtlString resToken;
int curPos= 0;

resToken= str.Tokenize("% #",curPos);
while (resToken != "")
{
   printf("Resulting token: %s\n", resToken);
   resToken= str.Tokenize("% #",curPos);
};

Output

Resulting Token: First
Resulting Token: Second
Resulting Token: Third