Re: [BackupPC-users] Digest::MD5 vs md5sum
Hi, gregrwm wrote on 2015-09-15 14:08:20 -0500 [[BackupPC-users] Digest::MD5 vs md5sum]: > the following commands demonstrate that either Digest::MD5 and gnu md5sum > are not compatible, or that i haven't got the backuppc md5 formula quite > right. can anyone set me straight? probably not, considering your obfuscated bash code. Where did you get the idea to 4b $s? You might try echo -n ning it instead. Not that I'd tried it or would feel inclined to do so. Actually, I have to admit that I just *did* try it. Hope that helps. Not sure what you are actually trying to do, though. Regards, Holger -- ___ BackupPC-users mailing list BackupPC-users@lists.sourceforge.net List:https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki:http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
[BackupPC-users] Digest::MD5 vs md5sum
the following commands demonstrate that either Digest::MD5 and gnu md5sum are not compatible, or that i haven't got the backuppc md5 formula quite right. can anyone set me straight? the commands below merely use the filesize, and the whole file since it's <256K, feed them both to md5sum, and show the result adjacent the filename. the below shows /etc/papersize and it's poolfile: $ alias zcat=/usr/share/?ackup??/bin/BackupPC_zcat > $ alias li=ls' -aFqldi --color --time-style=+%F" %a "%T' > $ 1b()(printf \\x$(printf %x $1)) > $ 2b()(1b $(($1 / 256));1b $(($1% 256))) > $ 4b()(2b $(($1%2**32/65536));2b $(($1%65536))) #write rightmost 4 bytes > $ 4b 513 |xxd #4b sanity tests > 000: 0201 > $ 4b 65539 |xxd > 000: 0001 0003 > $ 4b $((2**32-7))|xxd > 000: fff9 > $ 4b $((2**32+9))|xxd > 000: 0009 > $ md5sum --version|head -1 > md5sum (GNU coreutils) 8.13 > $ um()(s=$( cat $1|wc -c) m=$((4b $s; cat $1|sf)|md5sum);echo $(li $1) $m > s=$s) #li & md5 of uncompressed argfile > $ zm()(s=$(zcat $1|wc -c) m=$((4b $s;zcat $1|sf)|md5sum);echo $(li $1) $m > s=$s) #li & md5 of compressed argfile > $ sf()if [ $s -le $(( 256*1024)) ];then > cat #select filedata for md5 > > elif [ $s -le $((1024*1024)) ];then > > dd bs=128K count=1 > > tail -c128K > > else > > dd bs=128K count=1 > > dd bs=128K skip=6 count=1 > > fi > $ cat /etc/papersize > a4 > $ xxd /etc/papersize > 000: 6134 0a a4. > $ um /etc/papersize > 349898 -rw-r--r-- 1 root root 3 2014-01-01 Wed 17:39:09 /etc/papersize > 12cf0b6059ccc2701eb9e55277f161c2 - s=3 > $ zm /var/lib/backuppc/pc/127.0.0.1/0/f%2f/fetc/fpapersize > 19720838 -rw-r- 40 backuppc backuppc 11 2015-04-23 Thu 02:30:49 > /var/lib/backuppc/pc/127.0.0.1/0/f%2f/fetc/fpapersize > 12cf0b6059ccc2701eb9e55277f161c2 - s=3 > $ zm /var/lib/backuppc/cpool/7/a/5/*991 > 19720838 -rw-r- 40 backuppc backuppc 11 2015-04-23 Thu 02:30:49 > /var/lib/backuppc/cpool/7/a/5/7a59e82651106239413a38eb30735991 > 12cf0b6059ccc2701eb9e55277f161c2 - s=3 > -- ___ BackupPC-users mailing list BackupPC-users@lists.sourceforge.net List:https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki:http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
