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From: ma740988 on 3 Aug 2006 21:12
The contents of my_file.txt is as follows:
0,524288,FFF,524288,1000
1,624288,F4F,32768,2000
-1,-1,-1,-1,-1


Now given:

# include <iostream>
# include <vector>
# include <string>
# include <fstream>
# include <sstream>


struct wfts {
int id;
int vp_size ;
int vp_mask;
int fp_size ;
int fp_mask;

wfts (
int id,
int vp_size,
int vp_mask_,
int fp_size,
int fp_mask )
: id ( -1 )
, vp_size ( 0 )
, vp_mask ( -1 )
, fp_size ( 0 )
, fp_mask ( -1 )
{}
// perhaps a friend to dump things..
};


bool
read_file ( std::ifstream& ifs,
std::vector < wfts >& wts_vec )
{
bool success ( false );
std::string line;

wts_vec.clear();

//ifs.ignore();
while ( std::getline( ifs, line, ',' ) )
{
std::cout << "std::string line = " << line << std::endl;
std::istringstream iss;
iss.str ( line ) ;

int id ( 0 );
int vp_size ( 0 ) ;
int vp_mask ( 0 );
int fp_size ( 0 ) ;
int fp_mask ( 0 );

iss >> id
>> vp_size
>> vp_mask
>> fp_size
>> fp_mask;
if ( id != -1 &&
vp_size != -1 &&
vp_mask != -1 &&
fp_size != -1 &&
fp_mask != -1 )
{
wts_vec.push_back (
wfts ( id,
vp_size,
vp_mask,
fp_size,
fp_mask ) );
}
}
if ( wts_vec.size() )
success = true;

return ( success );
}

int main()
{
std::ifstream ifs ( "my_file.txt" );

std::vector < wfts > wfts_vec;
if ( read_file ( ifs, wfts_vec ) )
{
std::cout << " Id " << " "
<< " vp_size " << " "
<< " vp_mask " << " "
<< " fp_size " << " "
<< " fp_mask " << std::endl;

for ( std::vector < wfts >::size_type idx ( 0 );
idx < wfts_vec.size();
++idx )
{

std::cout << wfts_vec [ idx ].id << " "
<< wfts_vec [ idx ].vp_size << " "
<< wfts_vec [ idx ].vp_mask << " "
<< wfts_vec [ idx ].fp_size << " "
<< wfts_vec [ idx ].fp_mask << " "
<< std::endl;
}
}

The output doesn't reflect what I anticipate The fundamental issue
surrounds isstringstream but I'm unsure why. Any help appreaciated.

An aside:
I would have thought I could do this one in my sleep by now. :) Time
to brush up on those streams again.

From: LR on 3 Aug 2006 22:30
ma740988 wrote:
> The contents of my_file.txt is as follows:
> 0,524288,FFF,524288,1000
> 1,624288,F4F,32768,2000
> -1,-1,-1,-1,-1
>
>
> Now given:
>
> # include <iostream>
> # include <vector>
> # include <string>
> # include <fstream>
> # include <sstream>
>
>
> struct wfts {
> int id;
> int vp_size ;
> int vp_mask;
> int fp_size ;
> int fp_mask;
>
> wfts (
> int id,
> int vp_size,
> int vp_mask_,
> int fp_size,
> int fp_mask )
> : id ( -1 )
> , vp_size ( 0 )
> , vp_mask ( -1 )
> , fp_size ( 0 )
> , fp_mask ( -1 )
> {}

I don't quite understand the above ctor. You seem to pass values, but
set everything to constants.

Why not
wfts()
:
id(0),
vp_size(0),
... etc
{}
and
wfts(int id_arg, int vp_size_arg, ... etc)
:
id(id_arg),
vp_size(vp_size_arg),
... etc
{}
and a ctor like this
wfts(const std::vector<std::string> &f) {
// lot's of checking to do here
// You may have problems with converting
// things like FFF to an int.
// You may also want to make sure that
// f has the right number of elements.
//
}
and a copy ctor
wfts(const wfts &w)....

> // perhaps a friend to dump things..
> };

Add some comparison operators (easier to do this in terms of <)
bool operator<(const wfts &w1, const wfts &w2) { .... }
bool operator!=(const wfts &w1, const wfts &w2) {
const bool result = (w1 < w2) || (w2 < w1);
return result;
}
bool operator!=(const wfts &w1, const wfts &w2) { ... }
>
>
> bool
> read_file ( std::ifstream& ifs,
> std::vector < wfts >& wts_vec )
> {
> bool success ( false );
> std::string line;
>
> wts_vec.clear();
>
> //ifs.ignore();
> while ( std::getline( ifs, line, ',' ) )
> {
The above line reads input from ifs up to the first ',' and puts it in line.

Try something like this.

// read a line
while(std::getline(ifs,line)) {

std::vector<std::string> fields;
std::istringstream ifields(line);
std::string t;
while(std::getline(ifields,t,',')) {
fields.push_back(t);
}

static const wfts wfts_final(-1,-1,-1,-1,-1);
const wfts w(fields);
if(w != wfts_final)
wts_vec.push_back(w);
// if the -1,-1... line might not be the last,
// then perhaps you want to break?
if(w == wfts_final)
break;

But NB, I haven't tried to compile any of this code, so buggen probably
lurk within.

LR




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