gtarsum

README

gtarsum

Compute hash for one tar file (or several tar files concurrently)

Installation

go get

go get github.com/VonC/gtarsum

releases

Artifacts from the latest release for Mac, Linux and Windows (64 bits only)

Usage

Normal: output hash

gtarsum <afile.tar>

a10840209cb1c93c6bb85a34e969cf7eaaf43128b477f0f900cac49b551d26bd

Multiple archives: hash comparison

gtarsum <afile.tar> <afile2.tar> ...

echo $?
# or
echo %ERRORLEVEL%

• compute hash for each archive concurrently, not sequentially
• exit 0 if all archives are identical
• exit 1 if one or several archives differ from the first

Verbose: with progress bar, copy hash to a file

• If the environment variable progress is set (to anything), it will display a progress bar for each files read in the tar file.

• If the environment variable progress is set (to a value ending with '.hash'), it will copy the result in the file 'xxx.hash'.

progress=1.hash gtarsum <afile.tar>

File 'ex.tar' (73): 100% [============================================================================]
File 'ex.tar' hash='a10840209cb1c93c6bb85a34e969cf7eaaf43128b477f0f900cac49b551d26bd'

cat 1.hash
a10840209cb1c93c6bb85a34e969cf7eaaf43128b477f0f900cac49b551d26bd

Verbose: with progress bar, for multiple archives

progress=2.hash gtarsum <afile.tar> gtarsum <afile2.tar> ...

File 'ex.tar' (73): 100% [============================================================================]
File 'ex2.tar' (132): 100% [==========================================================================]
File 'ex.tar' hash='a10840209cb1c93c6bb85a34e969cf7eaaf43128b477f0f900cac49b551d26bd'
File 'ex2.tar' hash '543a12be3e27d85e94cdfac3eae186cd7d54d4994ccd3db0f96a8077578a6bed' differs

cat 2.hash1
a10840209cb1c93c6bb85a34e969cf7eaaf43128b477f0f900cac49b551d26bd
cat 2.hash2
543a12be3e27d85e94cdfac3eae186cd7d54d4994ccd3db0f96a8077578a6bed

• compute sha256 for each archive, concurrently (not sequentially)
• display hash for each archive
• same rule as before: if the environment variable progress ends with .hash, the hashes are accessible in xxx.hash1/xxx.hash2/... files.

Version

Use -v, or --version or version

gtarsum -v
Git Tag   : v0.0.1-3-gfc947e7
Build User: VonC
Version   : v0.0.1
BuildDate : 20200904-105250

Tar hash

• Compute hash for each files found in the tar
• Sort the list of file names part of the archive
• Compute a hash from the concatenation of the filnames hashes

So if a different tar file has the same files but in a different order, or different date/owner, the global hash can still be the same as an previous archive.