question about md5sum check lists

Forum: Other Help Topics
Topic: question about md5sum check lists
started by: livefrom2006

Posted by livefrom2006 on Oct. 14 2006,22:10

hi,

have been reading the documentation for the md5sum program,
and have a question regarding the checking option - ie the

md5sum -c file_of_items_to_check

form of the command. The documentation states that the list
file contains a line for each file to be checked consisting of the
following three parts:

1. the md5 checksum
2. a file type indicator
3. the file to check, with optional path name.

what I am unsure about is item 2.
It is stated that binary files should contain a "*" in this location
while text files should contain " " - ie a blank space.

if this is the case, then how come the .md5.txt files for the
dsl .iso files contain a " " in this position - I would have thought
that these files would be considered as a binary file, and thus should have a "*" in this position.

I am assuming that the difference has something to do with the
way that white space and control chacters are treated - I have tried searching on the program name, but have not had and success. If anyone could clarify this matter, it would be much
appreciated.

on a related subject, have been trying to check a knoppix cd
using the md5sum program, and the supplied md5sums list.
have used the following procedure:

dsl toram 2 (boot options)
mount /mnt/cdrom
cd /mnt/cdrom
md5sum -c KNOPPIX/md5sum

the prompt re-appears in about 2 seconds - much to quick for
a check on knoppix. so tried using the "warn" feature - ie

md5sum -c -w KNOPPIX/md5sum

the results in the message "md5sum: Invalid Format" being printed numerous times down the screen. have checked
the file and all the entries seem fine. as an example, the first
line of the file is as follows:

f3086b686d99c6681718d1a49faab5bb *autorun.bat

while neither of these items is major, it has the potential to cause
problems if a corrupted download is not spotted. I also find that
getting details straight at the start can prevent problems further down the line.

as you may have guessed from the above comment, and my username I am new to linux - but enjoying the learning process!.

dsl is a great distro, and one of the few that does not suffer from
"kitchen sink" syndrome!.

regards, L.F.2006.