Directing a file into standard input

[romsok]

Hi,

I am doing an exercise from Thinking In C++ and it suggests "redirecting a file into the program's standard input".

Could someone please suggest how I can accomplish that.

[Bazzy]

Something like this should work:

streambuf *buf = cin.rdbuf(); // keep the cin buffer to restore it

ifstream file ( "something"); // create the file

cin.rdbuf( file.rdbuf() ); // redirect input

// use cin - it will read from the file -

cin.rdbuf ( buf ); // reset cin buffer to the previous one 

[tummychow]

What is the point of that anyway when you can just manipulate the ifstream directly as though it were an iostream? The interface and operators are largely the same.

[moorecm]

I'm not sure if this is what you mean, but in a *nix OS, on the command line you can pipe or redirect another programs output into your own program. For example, "cat file | ./yourprogram".

All your program has to do is read from cin to access the input.