C++ redirect cout

Bacchus

Hi,
When I use "cout" to print data to the command line I'd like to be able to print it to a text file aswell as a record.
Does anyone know how to do this? The only thing I can find is a command "rdbuf" used with "cout" but I can't get it to work. My only alternative is to print everything once with "cout" and once again to the file but that just messy and requires twice the code.
Any help would be much appreciated.

Bacchus

viboy

From memory something like :
[PHP]std::ofstream out("output.txt");
out.rdbuf(std::cout.rdbuf());
[/PHP]

will probably work for you.

If that doesn't work PM me and I'll send you some working code.

Mutant_Fruit

Write a function called "PrintString" and send it the string you want to print like this (psuedo code):

void PrintString(string mystring)
{
// use cout or whatever
printToScren(mystring);
printToFile(mystring);
}

So every time you want to display something on the screen *and* in a file, send the string to that function.

Bacchus

hey,
Thanks for the tips. What I have now is this..

char LOG_FILE_NAME[30];
sprintf(LOG_FILE_NAME,"FILES/log_file.txt");

ofstream LOG_FILE;
LOG_FILE.open(LOG_FILE_NAME,ios::out ); 

streambuf* sbuf = cout.rdbuf();

cout.rdbuf(LOG_FILE.rdbuf());
cout << "This is sent to file" << endl;
cout.rdbuf(sbuf);
cout << "This is sent to prompt" << endl;

That works okay now but do you know how I can get it to write to both the prompt and the file in the one command.

Thanks,
Bacchus

Mutant_Fruit

Bacchus wrote:

That works okay now but do you know how I can get it to write to both the prompt and the file in the one command.

And...

Mutant_Fruit wrote:

Write a function called "PrintString" and send it the string you want to print like this (psuedo code):

void PrintString(string mystring)
{
// use cout or whatever
printToScreen(mystring);
printToFile(mystring);
}

You should be able to figure it from there

Bacchus

Cheers Mutant_Fruit, I did it the way you suggested aswell. I was just wondering was there some neat command that uses rdbuf(or something similar) to print to both.

Mutant_Fruit

Bacchus wrote:

Cheers Mutant_Fruit, I did it the way you suggested aswell. I was just wondering was there some neat command that uses rdbuf(or something similar) to print to both.

C++ may have something to do that, but i don't know

Just a FYI: C# does have something like that. Basically there is a "TraceListener" class to which you can add any number of streams. Then you can do something like Trace.WriteLine("My big long line of text"); and that long line of text will be written to each stream that was added to the TraceListener class. It could be a file, your standard console, a socket, whatever.

This makes it easy to have one line of debug text to be sent to many places, exactly what you want :P

Bacchus

Mutant_Fruit wrote:

Just a FYI: C# does have something like that. Basically there is a "TraceListener" class to which you can add any number of streams. Then you can do something like Trace.WriteLine("My big long line of text"); and that long line of text will be written to each stream that was added to the TraceListener class. It could be a file, your standard console, a socket, whatever.

This makes it easy to have one line of debug text to be sent to many places, exactly what you want :P

Exactly what I want. I'll look into that, see if I can find anything. Thanks.