Reading words with trailing whitespace

[Brad Marts]

I am trying to read a file one word at a time, doing something with
each word in between each read. When the file has trailing
whitespace at the end of the last word, I wind up getting it twice.

Code:
#include<iostream>
#include<fstream>
#include<string>
using namespace std;

int main()
{
string str;
ifstream in("test.txt");

while(!in.eof())
{
in >> str;
// Do something with str, e.g.:
cout << str << " ";
}
cout << "\n";
in.close();
return 1;
}

If "test.txt" is:
this is a test

with whitespace after test,

The output is:
this is a test test

I know the problem is coming from the fact that I am not at eof
after reading test and the next read doesn't alter the contents
of str, but I'm not sure of how to make this work.

Thanks,
Brad

 

[Victor Bazarov]

I am trying to read a file one word at a time, doing something with
each word in between each read. When the file has trailing
whitespace at the end of the last word, I wind up getting it twice.

Code:
#include<iostream>
#include<fstream>
#include<string>
using namespace std;

int main()
{
string str;
ifstream in("test.txt");

while(!in.eof())
{
in >> str;
// Do something with str, e.g.:
cout << str << " ";
}
cout << "\n";
in.close();
return 1;
}

If "test.txt" is:
this is a test

with whitespace after test,

The output is:
this is a test test

I know the problem is coming from the fact that I am not at eof
after reading test and the next read doesn't alter the contents
of str, but I'm not sure of how to make this work.

Check the result of the operator>> before doing anything with
the 'str'. IOW:

in >> str;
if (in.good())
cout << str << " ";
else
cout << "<DONE>";

Victor

 

[Nudge]

I am trying to read a file one word at a time, doing something with
each word in between each read. When the file has trailing
whitespace at the end of the last word, I wind up getting it twice.

Does this answer your question?
http://www.parashift.com/c++-faq-lite/input-output.html#faq-15.5

 

[Brad Marts]

Does this answer your question?
http://www.parashift.com/c++-faq-lite/input-output.html#faq-15.5

Yes, it does. Thank you. Even after reading the faq for some time I still
missed it.