HP Integrity NonStop J-Series - Manual (Page 78)

RWCString b = recover(bistr); // 7
cout << a << endl; // Compare the two strings // 8
cout << b << endl;
return 0;
}
Program Output:
A string with tabs and a
newline.
A string with tabs and a
newline.
The job of function save(const RWCString& a, RWvostream& v) is to save the string a to the
virtual output stream v. Function recover(RWvistream&) restores the results. These functions do
not know the ultimate format with which the string will be stored. Here are some additional
comments on particular lines:
//1, //2 On these lines, a file output stream f is created for the file junk.dat. The default file
open mode for many PC compilers is text, requiring that the explicit flag ios::binary be
used to avoid automatic DOS new line conversion
[6] .
//3 On this line, an RWbostream is created from f.
//4 Because this clause is enclosed in braces { ... }, the destructor for f will be called here.
This will cause the file to be closed.
//5 The file is reopened, this time for input.
//6 Now an RWbistream is created from it.
//7 The string is recovered from the file.
//8 Finally, both the original and recovered strings are printed for comparison.
You could simplify this program by using class fstream, which multiply inherits ofstream and
ifstream, for both output and input. A seek to beginning-of-file would occur before reading the
results back in. Since some early implementations of seekg() have not proven reliable, the
simpler approach was not chosen for this example.