Recipe: Checksum and verification

md5sum
======
$ md5sum filename
#It generates 32 character string like 68b329da9893e34099c7d8ad5cb9c940 filename

$ md5sum filename > file_sum.md5

$ md5sum file1 file2 file3
b1946ac92492d2347c6235b4d2611184  file1
b1946ac92492d2347c6235b4d2611184  file2
b1946ac92492d2347c6235b4d2611184  file3

$ md5sum -c file_sum.md5
# It will output message whether checksum matches or not

md5deep
=======

$ md5deep -rl directory_path > directory.md5
# -r  for enable recursive.
$ -l for using relative path. By default it writes absolute file path in output

$ find directory_path -type f -print0 | xargs -0 md5sum >> directory.md5
#Alternate method