Appending to a log file (C++)

itz2000 · 10-27-2006, 06:36 AM

hey there.

I'm appending to a log file many messages and I decided to use system (to call for the shell via C++) so I'm doing this :

system(echo "found error in input inserted by user at" >> logfile && date >> logfile);

but my question is how can I append variable to the text such as :

void myFunc(char[] myCommentToLog)
{
system (myCommentToLog >> logfile);
}

it doesn't work... have you got any idea to offer how to solve it? or how to add the variable (myCommentToLog) in other way?

Thanks!

nhydra · 10-27-2006, 09:03 AM

You can do it in that way:
int some_int_var;

fprintf (file_handler, "Some text %i", some_int_var);

orgcandman · 10-27-2006, 09:14 AM

Just make sure that you open the file for appending.

Nylex · 10-27-2006, 09:20 AM

You can do something like:

Code:

ofstream out("myfile", ios::app);
out << myCommentToLog;

Edit: obviously you'll need to include fstream. Also, remember to close the file afterwards (with out.close()). One last thing: you know C++ has a string class, right?

itz2000 · 10-27-2006, 09:57 AM

Quote:

Originally Posted by Nylex

You can do something like:

Code:

ofstream out("myfile", ios::app);
out << myCommentToLog;

Edit: obviously you'll need to include fstream. Also, remember to close the file afterwards (with out.close()). One last thing: you know C++ has a string class, right?

thanks.. and yes, I do know that.