md5sum

[Patton Echols]

Christopher Chan wrote:
> On Wednesday, May 05, 2010 03:54 PM, terry wrote:
>   
>> I think I was told by a respondent to the list if this MD5sum and an ISO
>> disk  image in the same location, maybe a download folder some thing
>> like this; md5sum  ubuntu xxxxxx   xxx.iso and I would get the hash of
>> the disc to compare with on line so I don't waste a cd if the hash is
>> incorrect? I've not had much success with it. More so with  openssl
>> dgst  - md5 /path to iso./
>> Also. I saw where I could do this to get the hashes from a burned disk
>> in the cdrom by md5sum /media/sr0 to see if the disc is ok.
>> Also, which technique is used  md5sum  or sha256sum?, which I found both
>> listed on the web sight?
>> Which one is ubuntu's preference?
>> Thank you.
>>
>>     
>
> Give it a bit of time to finish. Something like this in a terminal:
>
> me at mycomputer:~$ md5sum osol-0906-x86.iso
> 86e19c89a30c9b91cbb096a758dea737  osol-0906-x86.iso
>
>   

Also, if you have the hashes in a file, formated like Christopher's 
result above.  then you can do something like this:

patton at mycroft:~/Documents/Homework$ md5sum -c hashes
CM-outline.odt: FAILED
G-outline.odt: OK
green.rtf: OK
md5sum: WARNING: 1 of 3 computed checksums did NOT match


Note, I intentionally changed the file after generating the hashes to 
show the result.   If you copy the hashes from a web site, note that a 
correctly formatted line has two spaces between the hash and the file 
name.  Leave only one and it will not work.