标准C++ 与MFC 6.0 中字符串的分割

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

typedef basic_string<char>::size_type S_T;
static const S_T npos = -1;

////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 = 0, index = 0, len = 0;
while( (index = src.find_first_of(tok, pre_index)) != npos )
{
if( (len = index-pre_index)!=0 )
v.push_back(src.substr(pre_index, len));
else if(trim==false)
v.push_back(null_subst);
pre_index = index+1;
}
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 = 0;
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=0; i<v1.size();i++)
{
cout<<v1[i].c_str()<<endl;
}

cout<<"-------------v2:"<<endl;
for(int j=0; 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=0; k<v3.size();k++)
{
cout<<v3[k].c_str()<<endl;
}
}
catch (char *s) {
cout<<s<<endl;
}

return 0;
}

2、CString版的：

#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[0];
for( long index=-1; (index=s.FindOneOf((LPCTSTR)delimits))!=-1; )
{
if(index != 0) pList->AddTail( s.Left(index) );
else if(!trim) pList->AddTail(nullSubst);
s = s.Right(s.GetLength()-index-1);
}
}

/*
* 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=0, CString nullSubst="")
{
ASSERT( !src.IsEmpty() && !delimit.IsEmpty() );
if(num==1)
{
pOutList->AddTail(src);
return;
}

int deliLen = delimit.GetLength();
long index = -1, lastSearchPosition = 0, cnt = 0;

while( (index=src.Find(delimit, lastSearchPosition))!=-1 )
{
if(index==lastSearchPosition)
pOutList->AddTail(nullSubst);
else
pOutList->AddTail(src.Mid(lastSearchPosition, index-lastSearchPosition));
lastSearchPosition = index + deliLen;

if(num)
{
++cnt;
if(cnt+1==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, 3, "<null>"); // <-----
printf("------[Split]-----\n");
POSITION pos3 = list3.GetHeadPosition();
while( pos3!= NULL )
{
printf( list3.GetNext(pos3) );
printf("\n");
}
return 0;
}