asked on

how do you save data it disk?

I have a program which stores its data in a list. How can I go about saving the contents of the list to disk so that thay can be read in at a later date?

ASKER CERTIFIED SOLUTION

galkin

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

gnik

ASKER

galkin,
Could you explain to me the actual process for getting the information to the disk.
Thanks.

galkin

Actual code depends on the item in the list you want to serialize to and from the disk. I guess everything is clear. Sa you have a list with 5 items and you wrote functions WriteItem and ReadItem that write and read single item to the disk.
First you open a file. Assume you are programming in windows

FILE* stream;
if( (stream = fopen( "fread.out", "w+" )) != NULL )
{
int item_count = 5;
// write number of item first
fwrite( &item_count , sizeof( item_count ), 1, stream );
//write items themselves
for(int i = 0; i < item_count; i++)
{
WriteItem(i);
}
fclose( stream );
}

To read
FILE* stream;
if( (stream = fopen( "fread.out", "r+" )) != NULL )
{
int item_count;
// read number of item first
fread( &item_count , sizeof( item_count ), 1, stream );
// allocate memory block dinamically according to the number of //items stored in file
Item *pItem = (Item *)malloc(sizeof(Item) * item_count);
//read items themselves
for(int i = 0; i < item_count; i++)
{
// read single item into memory block
ReadItem(i, pItem + i);
}
fclose( stream );
}