The "sha1sum" command:

Usage: fossil sha1sum FILE...

Compute an SHA1 checksum of all files named on the command-line.
If a file is named "-" then take its content from standard input.
Options:

   -h, --dereference     If FILE is a symbolic link, compute the hash
                         on the object that the link points to.  Normally,
                         the hash is over the name of the object that
                         the link points to.