C++写的split(string) 函数

source: http://guoxinmiao8.blog.sohu.com/102130312.html

一个十分有用的标准C++写的split(string) 函数

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

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。

view plainprint?

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

view plainprint?

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;
}