From md5sum --help:
Usage: md5sum [OPTION]... [FILE]...
Print or check MD5 (128-bit) checksums.
With no FILE, or when FILE is -, read standard input.
-b, --binary read in binary mode
-c, --check read MD5 sums from the FILEs and check them
-t, --text read in text mode (default)
The following three options are useful only when verifying checksums:
--quiet don't print OK for each successfully verified file
--status don't output anything, status code shows success
-w, --warn warn about improperly formatted checksum lines
--help display this help and exit
--version output version information and exit
The sums are computed as described in RFC 1321. When checking, the input
should be a former output of this program. The default mode is to print
a line with checksum, a character indicating type (`*' for binary, ` ' for
text), and name for each FILE.
Report md5sum bugs to firstname.lastname@example.org
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
For complete documentation, run: info coreutils 'md5sum invocation'