#include <iostream>
#include <fstream>
#include <string>
#include <windows.h>
using namespace std;
int main()
{
string vektor;
int i=0,v=0,n=0;
char vnos[100];
char znak;
fstream data("d:\\a.txt", ios::in|ios::out|ios::trunc);
if(data.is_open())
{
while(i<5)
{
cin.getline(vnos,200);
data<<vnos<<endl;
i++;
}
}else cout<<"Napaka Datoteke!"<<endl;
cout<<"HAY!1 "<<data.tellg()<<endl;
data.seekg( 0 );
cout<<"HAY!2 "<<data.tellg()<<endl;
if(data.is_open())
{ cout<<"HAY!3 "<<data.tellg()<<endl;
while(!data.eof() )
{
getline(data,vektor);
cout<<vektor<<endl;
}
}else cout<<"Napaka Datoteke!"<<endl;
cout<<"HAY!4 "<<data.tellg()<<endl;
data.seekg(0);
cout<<"HAY!5 "<<data.tellg()<<endl;
i=0;
if(data.is_open())
{
cout<<"HAY!6 "<<data.tellg()<<endl;
while(!data.eof())
{
znak=data.get();
i++;
if((znak=='\n') || (znak==' ') || (znak=='\0'))
{
n++;
}
cout<<znak;
}
}else cout<<"Napaka Datoteke!"<<endl;
v=i-n;
cout<<endl<<"vsi znaki"<<i<<endl;
cout<<"drugi znaki"<<n<<endl;
cout<<"vsi znaki"<<v<<endl;
data.close();
system("pause");
return 1;
}
[c++/fstream] seekg(0) not working?
Author
hey when i use fstream and seekg(0) twice, tellg() will return -1 and the program will not work properly( will not pass at data.is_open() )
is there any reason for this to happen?
thank you very much.
OK, the problem is:
Since you've gone till the EOF, the stream is now in a bad() state. You need to clear() it before you can seekg():
jfl.
while(!data.eof() ){ getline(data,vektor); cout<<vektor<<endl;}Since you've gone till the EOF, the stream is now in a bad() state. You need to clear() it before you can seekg():
cout<<"HAY!4 "<<data.tellg()<<endl;data.clear();data.seekg(0);jfl.
Also, you can do
You would need to store the length of the file first.
while (data.tellg() < length)// It reaches right before the EOF // instead ofwhile(!data.eof() )You would need to store the length of the file first.
data.seekg(0,ios::end); int length = textstream.tellg();This topic is closed to new replies.
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