Shell – OSX: Generate MD5 checksum recursively in a textfile containing files with corresponding checksum

hashsumosxshell-script

In a directory withmultiple subdirectories but only one folder deep containing tiff-files I'd like to generate a md5 checksum that writes the filename with the corresponding checksum into a textfile.

For example in directory TIFF I have 2 subdirectories:

TIFF
  |- b0125TIFF
        |- b_0000_001.tif
        |- b_0000_002.tif
        |- b_0000_003.tif
        |- b_0000_004.tif
  |- c0126TIFF
        |- c_0000_001.tif
        |- c_0000_002.tif
        |- c_0000_003.tif
        |- c_0000_004.tif

My expected textfile (checksum should be of course different):

** foo.md5:
188be1dbd4f6bcfdef8d25639473e6ec *b0125TIFF/b_0000_001.tif
188be1dbd4f6bcfdef8d25639473e6ec *b0125TIFF/b_0000_002.tif
188be1dbd4f6bcfdef8d25639473e6ec *b0125TIFF/b_0000_003.tif
188be1dbd4f6bcfdef8d25639473e6ec *b0125TIFF/b_0000_004.tif
188be1dbd4f6bcfdef8d25639473e6ec *c0126TIFF/c_0000_001.tif
188be1dbd4f6bcfdef8d25639473e6ec *c0126TIFF/c_0000_002.tif
188be1dbd4f6bcfdef8d25639473e6ec *c0126TIFF/c_0000_003.tif
188be1dbd4f6bcfdef8d25639473e6ec *c0126TIFF/c_0000_004.tif

How can I achieve that?

I know that this generates the checksum recursively in one directory:

find -s . -type f -exec md5 -q {} \; | md5

Best Answer

You don't want to pass the output of the find and md5 through md5, that would just give you an MD5 checksum of a lot of MD5 checksums...

$ find TIFF -type f -name '*.tif' -exec md5 {} ';' >md5.txt
$ cat md5.txt
MD5 (TIFF/b0125TIFF/file-1.tif) = d41d8cd98f00b204e9800998ecf8427e
MD5 (TIFF/b0125TIFF/file-2.tif) = d41d8cd98f00b204e9800998ecf8427e
MD5 (TIFF/b0125TIFF/file-3.tif) = d41d8cd98f00b204e9800998ecf8427e
MD5 (TIFF/c0126TIFF/file-1.tif) = d41d8cd98f00b204e9800998ecf8427e
MD5 (TIFF/c0126TIFF/file-2.tif) = d41d8cd98f00b204e9800998ecf8427e
MD5 (TIFF/c0126TIFF/file-3.tif) = d41d8cd98f00b204e9800998ecf8427e

The md5 implementation on macOS does not support verifying checksums with md5 -c unfortunately, but the shasum utility does:

$ find TIFF -type f -name '*.tif' -exec shasum {} ';' >sums.txt
$ cat sums.txt
da39a3ee5e6b4b0d3255bfef95601890afd80709  TIFF/b0125TIFF/file-1.tif
da39a3ee5e6b4b0d3255bfef95601890afd80709  TIFF/b0125TIFF/file-2.tif
da39a3ee5e6b4b0d3255bfef95601890afd80709  TIFF/b0125TIFF/file-3.tif
da39a3ee5e6b4b0d3255bfef95601890afd80709  TIFF/c0126TIFF/file-1.tif
da39a3ee5e6b4b0d3255bfef95601890afd80709  TIFF/c0126TIFF/file-2.tif
da39a3ee5e6b4b0d3255bfef95601890afd80709  TIFF/c0126TIFF/file-3.tif

$ shasum -c sums.txt
TIFF/b0125TIFF/file-1.tif: OK
TIFF/b0125TIFF/file-2.tif: OK
TIFF/b0125TIFF/file-3.tif: OK
TIFF/c0126TIFF/file-1.tif: OK
TIFF/c0126TIFF/file-2.tif: OK
TIFF/c0126TIFF/file-3.tif: OK

shasum calculates the SHA1 hash of a file by default.

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