一个十分有用的标准C++写的split(string) 函数

http://doserver.net/post/standard_template_library_stl_split_function_cpp.php?page=2&part=1

 这段时间在Linux开发防火墙还有查找ARP攻击的源的软件，需要

用到这个功能，本来自己也写了一个，感觉有点Bug，就在CSDN

搜索了一下，找到了这个，不错！



标准C++字符串string以及MFC6.0字符串CString的tokenize和

split函数。

标准串的：

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

  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 = -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;
}

/********************************************   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 = -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;
}

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;
}