sha1sum(1) - compute and check SHA1 message digest
-b, --binary
       read in binary mode
-c, --check
       read SHA1 sums from the FILEs and check them
-t, --text
       read in text mode (default)
       don't print OK for each successfully verified file
       don't output anything, status code shows success
-w, --warn
       warn about improperly formatted checksum lines
       with --check, exit non-zero for any invalid input
--help display this help and exit
       output version information and exit