[转]标准C++字符串string以及MFC6.0字符串CString的tokenize和split函数

标准字符串的方法：

 /******************************************** 

   the tokenize function for std::string 

 *********************************************/
 #include <string>
 #include <vector>
 #include <iostream>
 using namespace std; 

 typedef basic_string<char>::size_type S_T;
 static const S_T npos = -; 

 ////trim指示是否保留空串，默认为保留。
 vector<string> tokenize(const string& src, string tok,  bool trim=false, string null_subst="")
 {
  if( src.empty() || tok.empty() ) throw "tokenize: empty string\0"; 

  vector<string> v;
  S_T pre_index = , index = , len = ;
  while( (index = src.find_first_of(tok, pre_index)) != npos )
  {
   if( (len = index-pre_index)!= )
    v.push_back(src.substr(pre_index, len));
   else if(trim==false)
    v.push_back(null_subst);
   pre_index = index+;
  }
  string endstr = src.substr(pre_index);
  if( trim==false ) v.push_back( endstr.empty()? null_subst:endstr );
  else if( !endstr.empty() ) v.push_back(endstr);
  return v;
 } 

 ////使用一个完整的串delimit（而不是其中的某个字符）来分割src串,没有trim选项，即严格分割。
 vector<string> split(const string& src, string delimit, string null_subst="")
 {
  if( src.empty() || delimit.empty() ) throw "split: empty string\0"; 

  vector<string> v;
  S_T deli_len = delimit.size();
  long index = npos, last_search_position = ;
  while( (index=src.find(delimit, last_search_position))!=npos )
  {
   if(index==last_search_position)
    v.push_back(null_subst);
   else
    v.push_back( src.substr(last_search_position, index-last_search_position) );
   last_search_position = index + deli_len;
  }
  string last_one = src.substr(last_search_position);
  v.push_back( last_one.empty()? null_subst:last_one );
  return v;
 } 

 // test
 int main(void)
 {
  string src = ",ab,cde;,,fg,," ;
  string tok = ",;" ; 

  vector<string> v1 = tokenize(src, tok ,true);
  vector<string> v2 = tokenize(src, tok ,false, "<null>"); 

  cout<<"-------------v1:"<<endl;
  for(int i=; i<v1.size();i++)
  {
   cout<<v1[i].c_str()<<endl;
  } 

  cout<<"-------------v2:"<<endl;
  for(int j=; j<v2.size();j++)
  {
   cout<<v2[j].c_str()<<endl;
  } 

  try{ 

   string s = "######123#4###56########789###";
   string del = "";//"###";
   vector<string> v3 = split(s, del, "<null>");
   cout<<"-------------v3:"<<endl;
   for(int k=; k<v3.size();k++)
   {
    cout<<v3[k].c_str()<<endl;
   }
  }
  catch (char *s) {
   cout<<s<<endl;
  } 

  return ;
 }

CString的方法：

 #include <stdio.h>
 #include <afx.h> 

 /*
  * 该函数用delimits里的字符拆分s，传出一个CStringList指针pList，
  * 若trim为真，则不保留分割后的空串(注意不是空白字符)。比如：
  * Tokenize( "a,bc;,d,", ",;", &out_list, TRUE)
  * 会返回3个串：a、bc、d。
  * 若trim为FALSE，则用nullSubst用来替代分割后的空串，比如：
  *  Tokenize( "a,bc;,d;", ",;", &out_list, FALSE,"[null]" )
  * 会返回5个串：a、bc、[null]、d、[null]。
  * trim默认为FALSE，nullSubst默认为空串。
  */
 void Tokenize(CString s, CString delimits, CStringList* pList, BOOL trim=FALSE, CString nullSubst="")
 {
  ASSERT( !s.IsEmpty() && !delimits.IsEmpty() ); 

  s += delimits[];
  for( long index=-; (index=s.FindOneOf((LPCTSTR)delimits))!=-; )
  {
   if(index != ) pList->AddTail( s.Left(index) );
   else if(!trim) pList->AddTail(nullSubst);
   s = s.Right(s.GetLength()-index-);
  }
 } 

 /*
  * 类似java字符串的split()方法。
  * 使用一个完整的串delimit（而不是其中的某个字符）来分割src串,没有trim选项，
  * 即严格分割。num用来确定最多分割为多少个串,如果是0（默认），则按照delimit
  * 分割，若为1，则返回源串。
  */
 void Split(const CString& src, CString delimit, CStringList* pOutList, int num=, CString nullSubst="")
 {
  ASSERT( !src.IsEmpty() && !delimit.IsEmpty() );
  if(num==)
  {
   pOutList->AddTail(src);
   return;
  } 

  int deliLen = delimit.GetLength();
  long index = -, lastSearchPosition = , cnt = ; 

  while( (index=src.Find(delimit, lastSearchPosition))!=- )
  {
   if(index==lastSearchPosition)
    pOutList->AddTail(nullSubst);
   else
    pOutList->AddTail(src.Mid(lastSearchPosition, index-lastSearchPosition));
   lastSearchPosition = index + deliLen; 

   if(num)
   {
    ++cnt;
    if(cnt+==num) break;
   }
  }
  CString lastOne = src.Mid(lastSearchPosition);
  pOutList->AddTail( lastOne.IsEmpty()? nullSubst:lastOne);
 } 

 // test
 int main(void)
 {
  CString s = ",ab;cde,f,,;gh,,";
  CString sub = ",;";
  CStringList list1,list2; 

  Tokenize(s,sub,&list1,TRUE,"no use"); // <-----
  printf("-------[Tokenize_trim]-------\n");
  POSITION pos1 = list1.GetHeadPosition();
  while( pos1!= NULL )
  {
   printf( list1.GetNext(pos1) );
   printf("\n");
  }
  Tokenize(s,sub,&list2,FALSE,"[null]"); // <-----
  printf("------[Tokenize_no_trim]-----\n");
  POSITION pos2 = list2.GetHeadPosition();
  while( pos2!= NULL )
  {
   printf( list2.GetNext(pos2) );
   printf("\n");
  } 

  CStringList list3;
  s = "###0123###567######89###1000###";
  sub = "###";
  Split(s,sub,&list3, , "<null>"); // <-----
  printf("------[Split]-----\n");
  POSITION pos3 = list3.GetHeadPosition();
  while( pos3!= NULL )
  {
   printf( list3.GetNext(pos3) );
   printf("\n");
  }
  return ;
 }