How to pass a string to ofstream::open for the file name

Question

This is my first C++ app. I'm using Visual C++ 2010 Express. I'm trying to write a console program that will write the line "alive" to the file alive.txt on my WD USB hard drive every 10 seconds to prevent the drive from spinning down. I want the program to prompt me for the drive letter, and then use that to tell the program where the file is located. This works:

while (true)
{
Sleep(5000);
cout << "Past sleep";
ofstream AliveFile;
AliveFile.open ("j:\\alive.txt");
AliveFile << "alive" << endl;
AliveFile.close();
} 
return 0;

But when I get the drive letter from the console input and save the path to a string and pass that to AliveFile.open it doesn't work:

string DriveLetter;
cout << "What is the drive letter for the drive you want to keep awake?" << endl;
getline(cin, DriveLetter);
cin.clear();
string Path;
Path = "\"" + DriveLetter + ":\\alive.txt\"";
cout << Path << endl;

while (true)
{
Sleep(10000);
ofstream AliveFile;
AliveFile.open ( Path );
AliveFile << "alive" << endl;
AliveFile.close();
} 
return 0;

The path comes out fine when i cout << Path so I do not understand why AliveFile.open(Path) does not work.

Are you sure that `DriveLetter` is a string of exactly one letter? Did you check its length? Did you try to debug your program with a debugger? — Basile Starynkevitch, Feb 14 '12 at 21:24

score 1 · Accepted Answer · answered Feb 14 '12 at 21:25

1

Path = "\"" + DriveLetter + ":\\alive.txt\"";  // Why adding \ before the root.

Try -

Path = DriveLetter + ":\\alive.txt\";

answered Feb 14 '12 at 21:25

Mahesh

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Ah that makes sense. I was thinking I needed the quotes around it. Thank you! – 0xDECAFBAD Feb 14 '12 at 21:39
Usually only need the quotes if you are constructing an argument string to use in a system or shell call. – GTAE86 Feb 14 '12 at 21:43

How to pass a string to ofstream::open for the file name

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