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POAre arrays stored as a pointer or in their entirety inside C struct's? (was: How to dump structs to disk when some fields are pointers?)
 

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  1. POAre arrays stored as a pointer or in their entirety inside C struct's? (was: How to dump structs to disk when some fields are pointers?)
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    <p>I'm writing a FUSE plugin in C. I'm keeping track of data structures in the filesystem through structs like:</p> <pre><code>typedef struct { block_number_t inode; filename_t filename; //char[SOME_SIZE] some_other_field_t other_field; } fs_directory_table_item_t; </code></pre> <p>Obviously, I have to read (write) these structs from (to) disk at some point. I could treat the struct as a sequence of bytes and do something like this:</p> <pre><code>read(disk_fd, directory_table_item, sizeof(fs_directory_table_item_t)); </code></pre> <p>...except that cannot possibly work as <code>filename</code> is actually a pointer to the <code>char</code> array.</p> <p>I'd really like to avoid having to write code like:</p> <pre><code>read(disk_df, *directory_table_item.inode, sizeof(block_number_t)); read(disk_df, directory_table_item.filename, sizeof(filename_t)); read(disk_df, *directory_table_item.other_field, sizeof(some_other_field_t)); </code></pre> <p>...for each struct in the code, because I'd have to replicate code and changes in no less than three different places (definition, reading, writing).</p> <p>Any DRYer but still maintainable ideas?</p>
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    1. COout of curiosity, which FUSE?
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    2. COoh, and is `filename` a pointer, or as your comment (and use of sizeof operator) implies, an array? (in the latter case, you'd have no problem..)
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    3. COThis FUSE: http://fuse.sourceforge.net/ And yes, `filename` is a fixed length char array. (At least, it is for the foreseeable future.)
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