Unix and Linux Stack Exchange
Unix and Linux Stack Exchange

Questions tagged [checksum]

160 questions
261
votes
21 answers

How do I get the MD5 sum of a directory's contents as one sum?

The md5sum program does not provide checksums for directories. I want to get a single MD5 checksum for the entire contents of a directory, including files in sub-directories. That is, one combined checksum made out of all the files. Is there a way…
user17429
45
votes
1 answer

Why does verifying SHA256 checksum with `sha256sum` fail on Debian and work on Ubuntu?

On Ubuntu 14.04, sha256sum from coreutils works as I expected: echo 879dd0d7637876be4796f7e6f194a111d21088be85cfe717fc97e2e7f05e79d2 /tmp/myfile | sha256sum -c /tmp/myfile: OK However, the exact same command with the exact same file on Debian…
gertvdijk
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34
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7 answers

How can I generate SHA3 if there is no sha3sum command in coreutils?

I have sha1sum or sha512sum on an average Linux distro. But where is the sha3sum command that can generateSHA-3 commands?
pepite
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25
votes
2 answers

md5sum prepends '\' to the checksum

Why md5sum is prepending "\" in front of the checksum when finding the checksum of a file with "\" in the name? $ md5sum /tmp/test\\test \d41d8cd98f00b204e9800998ecf8427e /tmp/test\\test The same is noted for every other utility.
jsaji
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23
votes
3 answers

How do I view the btrfs checksum of a file?

Btrfs calculates a crc32c checksum for each file. Is there a way I can view what checksum is stored (as opposed to just reading the file and recalculating it)?
jl6
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23
votes
1 answer

`mount -o loop` changes mounted ISO image file

It looks like mount -o loop changes the mounted image file. I downloaded the ISO image file and checked its SHA-1 checksum. Then I mounted that ISO file and the checksum changed. Here are the exact steps I made, a copy-paste from my console, CentOS…
user77422
21
votes
3 answers

Verifying a large directory after copy from one hard drive to another

I have a home file server that I use Ubuntu on. Recently, one of my drives filled up so I got another and threw it in there. I have a very large folder, the directory is about 1.7 T in size and contains a decent amount of files. I used GCP to COPY…
Peter A
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21
votes
4 answers

Suppress filename from output of sha512sum

Maybe it is a trivial question, but in the man page I didn't find something useful. I am using Ubuntu and bash. The normal output for sha512sum testfile is testfile How to suppress the filename output? I would like to obtain…
BowPark
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20
votes
7 answers

Why compute checksums of downloaded files?

I often see a checksum given next to a file available for download. The purpose of this practice eludes me. It is obviously to detect corrupt files, but what could be the cause of this corruption and is it at all likely? Surely the file will not be…
Karolis Juodelė
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19
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6 answers

Print SHA sums without "-" at the end?

Is it possible to have SHA sums print without the - appended to the end? $ echo test | sha1sum 4e1243bd22c66e76c2ba9eddc1f91394e57f9f83 - <--- this "-" dash/hyphen I know we can use awk and other command line tools, but can it be done without…
user325067
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18
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4 answers

How to check if the ISO was written to my USB stick without errors?

I followed these DebianEeePC HowTo InstallUsingStandardInstaller instructions at the Debian Wiki, to write a Debian ISO to my USB. dd if=debian-*-netinst.iso of=/dev/sdX Using sha1sum, I can check the checksums of my downloaded ISO file. How can I…
Village
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18
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3 answers

How to check if a file is corrupt or not?

Are there any general solutions to check if a file is corrupt or not? For example, whether a video file is bad, or a compressed file is corrupt, etc.
LanceBaynes
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16
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1 answer

Splitting a small file into 512 byte segments changes it, but splitting it in 1k segments doesn't

So I'm trying to split a 64MB file FileCarve.001 into 512 byte segments (each block is 512 bytes long). I need to make sure the file has the same data when split into smaller files, so I cat all the files to standard out and pipe it into sha256sum…
FlashDaggerX
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15
votes
3 answers

Diffference between Sha1sum, Sha256sum and Md5sum

What is the difference between Sha1sum, Sha256sum and Md5sum ? and how to check all these for some iso file? and how to create md5sum.txt file in ubuntu ?
Marko Blanka
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14
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5 answers

Does gzip add integrity/crc check to a .tar?

I run commands: tar -cf myArchive.tar myDirectory/ gzip myArchive.tar then I copy the file over a lot of unreliable mediums, and later I unpack it using: tar -xzf myArchive.tar.gz The fact that I compressed the tar-ball, will that in any way…
Aksel Willgert
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