code doesnt work......please help me..

[sachin bond]

The following code(in c++) is supposed to divide a file into 'n' different
files.

suppose i'm having a file called "input.zip".

The execution of the following code should divide "input.zip" into 'n'(user
specified) different files.

However the code currently..though makes 'n' different files... the divided
contents are stored only in the first of the 'n' files.

That is.. if "input.zip" has 25kb size, and if i want to divide it into 5
different files... then,
actually i should have 5 files with 5 kb each. but this code only gives me 1
file with 5 kb and the rest 4 files are all 0kb.




void breaker()
{


long int temppos = 0,pos = 0;
int n = 0;
char choice =' ';
char file[20] = "input.zip",filename[2][30];
char byte[1] = " " ;

strcpy(filename[0],file);
strcpy(filename[1],filename[0]);
strcat(filename[1],"0");

ifstream infile(filename[0],ios::binary);


infile.seekg(0,ios::end);
pos=infile.tellg();

do
{
cout<<" file size in kb : "<<pos/1000;
cout<<"\nenter number files to be broken into: ";
cin>>n;
temppos=pos/n;
cout<<temppos<<"\n do you want to continue?..press q to re-enter number of
files..or any other key to continue..";
choice = getch();

}while(choice=='q');

int ctr=0;


ofstream outfile(filename[1],ios::binary);

infile.seekg(0,ios::beg);

char str[1];

infile.read(str,1);

char ext[1]="0";



for(int i=0;i<n;i++)
{
ctr=0;
while(ctr<temppos)
{


outfile.write(str,1);


infile.read(str,1);

ctr++;
}
ext[0]++;
outfile.close();
strcpy(filename[1],filename[0]);
strcat(filename[1],ext);
ofstream outfile(filename[1],ios::binary);

}



outfile.close();
infile.close();


}

 

[Kevin Goodsell]

void breaker()
{
long int temppos = 0,pos = 0;
int n = 0;
char choice =' ';
char file[20] = "input.zip",filename[2][30];
char byte[1] = " " ;

Ouch! Buffer overflow already. The string " " has two characters: ' ' and
'\0'. You tried to store it in an array that can hold only one character.

No. It's a constraint violation that should not compile.


8.5.2 Character arrays [dcl.init.string]

2 There shall not be more initializers than there are array elements.
[Example:
char cv[4] = "asdf"; // error
is ill-formed since there is no space for the implied trailing '\0'.
]


-Kevin