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How to read the whole TXT file into one string?

 
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How to read the whole TXT file into one string?
crammer008
post 28 Mar, 2006 - 07:51 PM
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Dear all,

How to read the whole TXT file into one string?

The TXT file is a multi-line file and its size is not known.

Looking forward to your guidance!
Thanks a lot

Crammer008
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Amadeus
post 28 Mar, 2006 - 09:22 PM
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g++ -o drink whiskey.cpp

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How can the size not be known? Is it an open text file that is being written to while it is being read from. Here is a link to some common filke i/o manipulation:
http://www.cplusplus.com/doc/tutorial/files.html
As discussed on that page, you can obtain the file size like so:
CODE

#include <iostream>
#include <fstream>
using namespace std;

int main () {
 long begin,end;
 ifstream myfile ("example.txt");
 begin = myfile.tellg();
 myfile.seekg (0, ios::end);
 end = myfile.tellg();
 myfile.close();
 cout << "size is: " << (end-begin) << " bytes.\n";
 return 0;
}

That determined size can then be used to read the file to a single string object.
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crammer008
post 28 Mar, 2006 - 11:25 PM
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Thank you very much!

You code helps to get the size of the file:)

My question is how to read the whole file into a string.
Every time, the file will be produced with different size. This is the reason I said the size is unknown.

Thank you:)
Crammer008
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Amadeus
post 29 Mar, 2006 - 03:53 AM
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g++ -o drink whiskey.cpp

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You would check the file size everytime you need to read it. As for reading it to the string, you can do it several ways:
CODE

string str,strTotal;
ifstream in;
in.open("myfile.txt");
getline(in,str);
while ( in ) {
  strTotal += str;
  getline(in,str);
}

This will read the file line by line and append it to a string...keep in mind this method will take out the newlines, so if you want them, you'll have to put them in yourself...

There are other methods as well.
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