lockfile-progs 0.1.17build1 (amd64 binary) in ubuntu bionic

 This package includes several programs to safely lock and unlock
 files and mailboxes from the command line. These include:
 .
   lockfile-create
   lockfile-remove
   lockfile-touchlock
   mail-lock
   mail-unlock
   mail-touchlock
 .
 These programs use liblockfile to perform the file locking and
 unlocking, so they are guaranteed compatible with Debian's
 file locking policies.