string.h - strsep

string.h - strsep

[Ömer Rauf Atay]

I think my string.h file does not include the strsep function.
My system is Sun Os 5.7 using gcc 2.95

I tried to use strtok instead but it simply skip the empty tokens.
 
 Any comments?
 

Re: string.h - strsep

[Gokhan Kisacikoglu]

>  Any comments?
> 

Using the <string> library from the standard templates instead; but you
will have to do some work. You can find more info at:

http://www.sgi.com/tech/stl/basic_string.html

For example, to tokenize a string;

#include <string>
#include <vector>

// headers necessary only for testing:
//	
#include <iostream>
#include <iterator>
#include <algorithm>

using namespace std;

typedef vector <string> string_array;

unsigned int 
tokenize(const string &_str, 
	const string &_delim, 
	string_array &_tokens )
{
    _tokens = string_array();
    if ( _str.empty() ) return 0;
    
    for ( string :: size_type spos = 0; 
	    spos != _str.size(); 
	    spos += _delim.size() )
    {
	string :: size_type epos = _str.find( _delim, spos );
	if ( epos == string :: npos )
	{
	    _tokens.push_back( string( _str, spos, epos ) );
	    break;
	}
	
	_tokens.push_back( string( _str, spos, epos-spos ) );
	spos = epos;
    }
    
    return _tokens.size();
}

int main(void)
{
    string_array tokens;
    
	// test: 1
    string str = "my string to be tokenized";
    string delimiter = " ";
    cout << "token count: " 
	<< tokenize( str, delimiter, tokens ) << endl;
    
    copy( tokens.begin(), tokens.end(), 
	ostream_iterator <string> ( cout, "_" ) );
    cout << endl;
    
	// test: 2
    cout << "token count: " 
	<< tokenize( "another string to-!be-!tokenized-!", "-!", tokens ) 
	<< endl;
    
    copy( tokens.begin(), tokens.end(), 
	ostream_iterator <string> ( cout, "_" ) );
    cout << endl;
    
	// test: 3
    cout << "token count: " 
	<< tokenize( "", " ", tokens ) << endl;
    
    copy( tokens.begin(), tokens.end(), 
	ostream_iterator <string> ( cout, "_" ) );
    cout << endl;
}


Regards,
Gokhan

Re: string.h - strsep

[John Love-Jensen]

Hi Omer,

The strsep function is not a standard function.

Man page on strsep.
<http://www.neosoft.com/neosoft/man/strsep.3.html>

You'll have to write your own strsep from the man page spec, or solve your
parsing problem through different means.

I recommend the very cool, very schwing Spirit:
<http://spirit.sourceforge.net/index.php?doc=docs/v1_5/quick_start.html>

I think Spirit is either part of BOOST, or soon to be part of BOOST.  A good
portion of BOOST is very likely to become part of the next C++ standard,
which is probably 5-10 years out.
<http://www.boost.org>

I suspect GCC, as usual, will be a leader in incorporating the "highly
likely" technology of the C++ Working Group for the next C++ standard.
Especially in the area of Generic Programming via improved template
facility.  But keep in mind, those technologies are a moving target.

--Eljay