2019-09-05 00:39:23 +00:00
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# xsum
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2019-10-03 12:43:02 +00:00
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This stores a file mtime, a size, and a cryptographically secure content checksum
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2019-09-05 00:39:23 +00:00
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in an xattr, so that you can verify that your files aren't corrupted
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on filesystems that are dumb and don't include data checksums (e.g. apfs)
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2019-10-03 12:43:02 +00:00
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# background
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You can dd a few random bytes into the middle of an hfs+ or apfs filesystem,
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and, if they land in file data, an fsck/Disk First Aid on the filesystem
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will pass with flying colors. There is no file content checksum.
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2019-09-05 00:39:23 +00:00
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# author
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2019-10-03 12:43:02 +00:00
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Jeffrey Paul [sneak@sneak.berlin](mailto:sneak@sneak.berlin)
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