Message-ID: <33FC3689.52D3432D@nexus.edu.au>
Date: Thu, 21 Aug 1997 22:07:29 +0930
From: Tom Cook <tcook AT nexus DOT edu DOT au>
MIME-Version: 1.0
To: djgpp AT delorie DOT com
Subject: Re: Writing a struct to disk
References: <33F93687 DOT 14CE173 AT psu DOT edu>
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Kertis A. Henderson wrote:
> 
> Under djgpp, what is the best way to write a bunch of structs to a
> file?  For instance, I'd like to write a linked list to a file node by
> node, then be able to read the nodes back and reconstruct the list.  A
> node could be something like the following:
> 
> struct node {
>   int number;
>   unsigned char age;
>   char *name;
>   node *next;
> }
> 
> The ints and chars would be relatively easy, but I don't see how a
> variable length string could be written.  Of course, the node pointer
> wouldn't be written.
> 
> If anybody could help me out (or possibly point me in the right
> direction), I'd appreciate it.  Thanks for any input.
> 
> --
> 
> Kertis Henderson
> kah190 AT psu DOT edu

If you can use C++, try using the String class. First write the length
to disk...

fwrite( str.length(), INT_LENGTH, 1, SomeFile );

Then the string...

fwrite( (const char*)str, 1, str.length(), SomeFile );

Then when you read it again, read the length, then read that many bytes
into a char array, then assign the char array to the string.

There's probably an easier way, but this is how I do it :)

Hope this helps.

Tom Cook