# CRC32 checksums

**URL:** <https://discourse.julialang.org/t/crc32-checksums/107922>\
**Category:** General Usage\
**Created:** [December 21, 2023, 7:46pm UTC](https://discourse.julialang.org/t/crc32-checksums/107922 "2023-12-21T19:46:14Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![LeePhillips](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/leephillips/32/205514_2.png) [@LeePhillips](https://discourse.julialang.org/u/LeePhillips)\
**Post date:** [December 21, 2023, 7:46pm UTC](https://discourse.julialang.org/t/crc32-checksums/107922/1 "2023-12-21T19:46:14Z")

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Why are the checksums from `CRCR32c.crc32c` in the Standard Library different from the ones I get from the linux `crc32` command? Documentation suggests that they are both using the same algorithm.

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**Author:** ![stevengj](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stevengj/32/71_2.png) [@stevengj](https://discourse.julialang.org/u/stevengj)\
**Post date:** [December 21, 2023, 7:55pm UTC](https://discourse.julialang.org/t/crc32-checksums/107922/2 "2023-12-21T19:55:52Z")

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> [@LeePhillips](#):
>
> Why are the checksums from `CRC32c.crc32c` in the Standard Library different from the ones I get from the linux `crc32` command? Documentation suggests that they are both using the same algorithm.

`crc32c` computes the CRC32 **c** checksum, which is not the same thing as the CRC32 checksum (computed by [`crc32` on the command-line](https://www.commandlinux.com/man-page/man1/crc32.1.html)). For the latter, use the CRC32.jl package.

See e.g. [CRC32 vs CRC32c on stackoverflow](https://stackoverflow.com/questions/26429360/crc32-vs-crc32c), or the discussion of the Castagnoli (C) polynomial in the [CRC wikipedia article](https://en.wikipedia.org/wiki/Cyclic_redundancy_check#Standards_and_common_use).

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**Author:** ![LeePhillips](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/leephillips/32/205514_2.png) [@LeePhillips](https://discourse.julialang.org/u/LeePhillips)\
**Post date:** [December 21, 2023, 7:57pm UTC](https://discourse.julialang.org/t/crc32-checksums/107922/3 "2023-12-21T19:57:08Z")

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Ahh. Thanks!