I need to calculate a summary MD5 checksum for all files of a particular type (*.py for example) placed under a directory and all sub-directories.
What is the best way to do that?
The proposed solutions are very nice, but this is not exactly what I need. I'm looking for a solution to get a single summary checksum which will uniquely identify the directory as a whole - including content of all its subdirectories.
I want to add that if you are trying to do this for files/directories in a Git repository to track if they have changed, then this is the best approach:
git log -1 --format=format:%H --full-diff <file_or_dir_name>
And if it's not a Git directory/repository, then the answer by ire_and_curses is probably the best bet:
tar c <dir_name> | md5sum
However, please note that tar command will change the output hash if you run it in a different OS and stuff. If you want to be immune to that, this is the best approach, even though it doesn't look very elegant on first sight:
find <dir_name> -type f -print0 | sort -z | xargs -0 md5sum | md5sum | awk '{ print $1 }'
If you want really independence from the file system attributes and from the bit-level differences of some tar versions, you could use cpio:
cpio -i -e theDirname | md5sum
md5sum worked fine for me, but I had issues with sort and sorting file names. So instead I sorted by md5sum result. I also needed to exclude some files in order to create comparable results.
find . -type f -print0 \
| xargs -r0 md5sum \
| grep -v ".env" \
| grep -v "vendor/autoload.php" \
| grep -v "vendor/composer/" \
| sort -d \
| md5sum