error checking for opening a file

[technotrix411]

I m trying to use a iterative function for error checking to open a file?

the problem is that once it enters the error loop , it does not come out .. i think its due to the object (ifile) .. which is not changing ...with input of new filename...
void getfile()
{
char *filename;
filename=new char[256];
cout<<"\nEnter the source file path:";
cin>>filename;
ifile.open(filename,ios::in);
while(!ifile)
{
cerr<<"Error opening file , enter a new path "<<endl;
cin>>filename;
ifile.open(filename,ios::in);
}
ifile.read(filename,ios::in);
}

[archonmagnus]

I m trying to use a iterative function for error checking to open a file?

the problem is that once it enters the error loop , it does not come out .. i think its due to the object (ifile) .. which is not changing ...with input of new filename...
void getfile()
{
char *filename;
filename=new char[256];
cout<<"\nEnter the source file path:";
cin>>filename;
ifile.open(filename,ios::in);
while(!ifile)
{
cerr<<"Error opening file , enter a new path "<<endl;
cin>>filename;
ifile.open(filename,ios::in);
}
ifile.read(filename,ios::in);
}

Try using the good() and/or fail() members of the ifstream class as follows:

void getfile (void)
{
    // ... get the filename...
 
    // ifile.open(filename,ios::in);
    ifstream ifile (filename, ios::in);
 
    while(!ifile.good())
    {
        cerr<<"Error opening file , enter a new path "<<endl;
        cin>>filename;
        ifile.open(filename,ios::in);
    }
 
    // ... read the file
}
 

I believe that should work, although I have not tested it to confirm. For more information, see http://www.cplusplus.com/reference/iostream/ifstream/

[technotrix411]

Try using the good() and/or fail() members of the ifstream class as follows:

void getfile (void)
{
    // ... get the filename...
 
    // ifile.open(filename,ios::in);
    ifstream ifile (filename, ios::in);
 
    while(!ifile.good())
    {
        cerr<<"Error opening file , enter a new path "<<endl;
        cin>>filename;
        ifile.open(filename,ios::in);
    }
 
    // ... read the file
}
 

I believe that should work, although I have not tested it to confirm. For more information, see http://www.cplusplus.com/reference/iostream/ifstream/

i have used that too .. but its not helping ... i think the actual object i.e. ifile is not changing ... in this iterative loop

[weaknessforcats]

You need to:

ifile.clear();
 

to turn off the fail bit. Do this before you try to reopen the file.