Where is the GNU checksum file format defined?I don't see any mention of the checksum file format at the GNU documentation website
Where is the GNU checksum file format defined?
gnu;hashsum;checksum
The documentation for the sha2 utilities points to the documentation for md5sum which saysFor each file, md5sum outputs by default, the MD5 checksum, a space, a flag indicating binary or text input mode, and the file name. Binary mode is indicated with *, text mode with  (space). Binary mode is the default on systems where its significant, otherwise text mode is the default. If file contains a backslash or newline, the line is started with a backslash, and each problematic character in the file name is escaped with a backslash, making the output unambiguous even in the presence of arbitrary file names.The checksum files are simply the output of the corresponding utilities, so the above documents their format too.