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Problem opening ifstream twice ...

Joe
Hello -

I use a ifstream to open a file in my code. I read through it using
getline() and then I close() it. Later in the code I try to open the
same file but it fails. Here is the code:

ifstream InputFile;

char Line[MAXcharLine + 1]; // MAXcharLine = 512

InputFile.open( "XXX.dat");

if (InputFile == NULL)
{
// ERROR
}

while (InputFile.getl ine(Line, MAXcharLine))
{
// DO STUFF
}

InputFile.close ();

....

InputFile.open( "XXX.dat")

if (InputFile == NULL)
{
// This is where the code fails!
}

What is wrong that it doesn't work? If I don't do the getline() then
it works fine.

Thanks a lot,
Joe
Jul 22 '05 #1
2 2406
On 20 Jan 2004 06:52:14 -0800, Joe wrote:
InputFile.close ();

do InputFile.clear (); here.

--
Best regards from
Kamil Burzynski
Jul 22 '05 #2

"Joe" <un*******@yaho o.com> wrote in message
news:fc******** *************** ***@posting.goo gle.com...
Hello -

I use a ifstream to open a file in my code. I read through it using
getline() and then I close() it. Later in the code I try to open the
same file but it fails. Here is the code:

ifstream InputFile;

char Line[MAXcharLine + 1]; // MAXcharLine = 512

InputFile.open( "XXX.dat");

if (InputFile == NULL)
{
// ERROR
}

while (InputFile.getl ine(Line, MAXcharLine))
{
// DO STUFF
}

InputFile.close ();

...

InputFile.open( "XXX.dat")

if (InputFile == NULL)
{
// This is where the code fails!
}

What is wrong that it doesn't work? If I don't do the getline() then
it works fine.


The error bit in stream is set after your first file has been read completely
till eof.
This is not cleared automatically and is the duty of the programmer.
So call the clear function on the stream and it should be ok.

Best wishes,
Sharad
Jul 22 '05 #3

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