How to go through a file multiple times?

[lnwlfx44]

I am going through a file once in one do-while loop, closing the ifstream and re-opening it, and then running through 3 other do-while loops. The files open and close sucessfully, but only the body of the top loop in the code executes. Shouldn't the input go back to the beginning if I close and reopen the file?

This is how I'm closing and reopening:
infile.close();
infile.open(ifname, ios::in);

I COULD make infile, infile2, infile3, infile4.. but do I really need to do that if I'm just opening the same file?

[stravant]

Just change the position of the "get" pointer back to the start of the file.

http://www.cplusplus.com/reference/iostream/istream/seekg/

[Galik]

std::ifstream ifs;

// ... stuff ...

ifs.seekg(0); // move to beginning
ifs.clear(); // clear flags (like EOF) 

[moorecm]

I typically just let the scope destroy and recreate the stream:

for( int i = 0; i < n; ++i )
{
    std::ifstream fin( filename );
    // process file
}