excerpt 'man md5sum'
MD5SUM(1) User Commands MD5SUM(1)
md5sum - compute and check MD5 message digest
md5sum [OPTION] [FILE]...
Print or check MD5 (128-bit) checksums. With no FILE, or when FILE is
-, read standard input.
read in binary mode
read MD5 sums from the FILEs and check them
read in text mode (default)
The following two options are useful only when verifying checksums:
don't output anything, status code shows success
warn about improperly formatted checksum lines
--help display this help and exit
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.
You can read the 'man md5sum' to see how.
To compute the md5sum for a file, then 'md5sum somefile' will compute and create a md5 for the file.