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    <p>Offhand, the simplest way to do it is to write the structure out sequentially so that:</p> <pre><code>[trex item #1] [list item #1] [list item #2] [list item #3] [trex item #2] [list item #1] [list item #2] [list item #3] [list item #4] etc... </code></pre> <p>(Of course, this is just sort of the jist of it. These are binary writes and this is a visual only.)</p> <p>I'm hoping that <code>fn_len</code> describes the number of items in the linked list <code>struct list *filenames</code>. If so, this is a snap.</p> <p>On writing:</p> <ol> <li>Write out the first structure in the <code>trex</code> linked list</li> <li>Loop and write out the <code>struct list *filenames</code> from that first <code>trex</code> structure one at a time</li> <li>Repeat #1 with the next item in the <code>trex</code> linked list until the list is exhausted.</li> </ol> <p>On reading, remember: <em>all of your pointers are going to be worthless initially</em>. You have to stitch them together yourself. But the structures are arranged in the correct order in the file.</p> <ol> <li>Read the first <code>trex</code> structure. You know its size, reading it isn't a problem. Fix the <code>next</code> pointer to nothing.</li> <li>Loop and read each of the <code>struct list *filenames</code> one at a time. You know how many they are because of <code>fn_len</code> in the structure you just read. Stitch together that linked list and attach it to the trex structure.</li> <li>Repeat #1 with the next <code>trex</code> structure until EOF, join the structure onto the end of the linked list as appropriate.</li> </ol> <p>And that should take care of it. </p>
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    1. COThanks so much for the post- that's really helpful. Just to clarify, since each trex struct has a pointer to next trex struct (so we have a 2D array-like structure), I don't know how long each chain of trex structs is starting at each array index. Do you think it would be easiest to keep a list of how long each chain is?
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    2. COYou shouldn't have to know how long the list of `trex` is. The only reason it's handy to know how long each chain of `struct list` is so that when reading back, you don't have to decide if the next read is the next 'trex' or the next 'struct list'. You read each `struct list` until you've reached `fn_len` from the previous `trex`, and you read `trex` until EOF.
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    3. COThanks a ton! It works great now!
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