-s <source_file>, source file location
-c <copy_file>, copied file location
-d <source_dir> <copy_dir>, paths to the source and copy dirs
-h, usage and options (this help)
-l, see this script"
cpverify verifies that a file or directory structure has been copied or
burned without errors. That is, the copied file(s) is exactly the same
as the original. This is done by calculating a cryptographic checksum
using the md5 message-digest algorithm on each file from the source and
the copy destination. The checksums for each file are then compared. Any
difference indicates that the copied file is not the same as the
original source file. Name of the file that fail to match the original
source file is printed to stdo.
Initially this script was written to verify that a CD ROM backup has
been burned error free. Currently the script can verify whole
directory trees as well as single files.
To verify that a file ~/dev/src.tar.bz2 is the same as ~/backup/src.tar.bz2
$ cpverify -s ~/dev/src.tar.bz2 -c ~/backup/src.tar.bz2
To verify that dir structure ~/backup have been burned correctly to
$ cpverify -d ~/backup /mnt/cdrom
To verify that two CD ROMS are identical, where the mounting points are
/mnt/cdrom and /mnt/cdrom2
$ cpverify -d /mnt/cdrom /mnt/cdrom2
In August 2004 a collision has been found in MD5 and other hash functions.
This means that it is possible to find two messages with the same hash, but
the attacker can't determine what the hash will be. Immediate implications of
this depend on how and where MD5 is used. I can only advise to learn about
this issue and judge whether it is safe to keep on using MD5 until it will
get replaced by a safer alternative.