Use of these interfaces should be restricted to only applications written on BSD platforms. Use of these interfaces with any of the system libraries or in multi-thread applications is unsupported.
The .pag file will contain holes so that its apparent size may be larger than its actual content. Older versions of the UNIX operating system may create real file blocks for these
holes when touched. These files cannot be copied by normal means ( cp(1), cat(1), tar(1), ar(1))
without filling in the holes.
dptr pointers returned by these subroutines point into static storage that is changed by subsequent calls.
The sum of the sizes of a key/content pair must not exceed the internal block size (currently 1024 bytes). Moreover all key/content pairs that hash together must fit on a single block. store will return an error in the event that a disk block fills with inseparable data.
delete() does not physically reclaim file space, although it does make it available for reuse.
The order of keys presented by firstkey() and nextkey() depends on a hashing function, not on anything interesting.
There are no interlocks and no reliable cache flushing; thus concurrent updating and reading is risky.
The database files (file.dir and file.pag) are binary and are architecture-specific (for example, they depend on
the architecture's byte order.) These files are not guaranteed to be portable across architectures.
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