48 lines
1.7 KiB
Text
48 lines
1.7 KiB
Text
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This utility is a wrapper for the md5(3), sha1(3) and rmd160(3)
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routines.
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It is remarkably similar to the digest package, except that it
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can recursively checksum directory trees.
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While a simple checksum on a tar file is usually satisfactory, once
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said archive has been extracted, it is virtually impossible to
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repackage the extracted tree in a form that can yield a repeatable
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checksum. To be specific, changes in timestamps and ownership, and
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changes in file ordering within directories can affect the checksum of
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the archive, while not really impacting the actual code at all.
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The algorithm used to checksum a directory in this implementation is
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as follows:
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cd into directory
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initialize MASTER_HASH
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walk directory tree, sorting all entries
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foreach entry
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if it is a directory:
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skip it if it is named "RCS", "CVS", or "SCCS"
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initialize SLAVE_HASH
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add the string "d " into SLAVE_HASH
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add the pathname of the directory into SLAVE_HASH
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finish SLAVE_HASH
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fold the hexified SLAVE_HASH result into MASTER_HASH
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if it is a file:
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initialize SLAVE_HASH
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add the string "f " into SLAVE_HASH
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add the pathname of the file into SLAVE_HASH
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finish SLAVE_HASH
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fold the hexified SLAVE_HASH result into MASTER_HASH
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initialize SLAVE_HASH
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add the contents of the file into SLAVE_HASH
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finish SLAVE_HASH
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fold the hexified SLAVE_HASH result into MASTER_HASH
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if it is a symbolic link
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initialize SLAVE_HASH
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add the string "l " into SLAVE_HASH
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add the pathname of the link into SLAVE_HASH
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finish SLAVE_HASH
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fold the hexified SLAVE_HASH result into MASTER_HASH
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initialize SLAVE_HASH
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add the contents of the link into SLAVE_HASH
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finish SLAVE_HASH
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fold the hexified SLAVE_HASH result into MASTER_HASH
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