Dear developers.
As a long time rar user, one of these days I decided to search for a free open-source alternative to it the way I could replace my backup script (Windows batch), so I chose 7z beacause of it's features. It's open-source, very good compression ratio compared to rar and supports AES encryption.
First of all I'm going to describe what I use with rar so you can better understand:
Fast compression ratio
Include and exclude files from list using <@listfiles...>
Create a archive name in the form archive_date(yyyymmdd)-time(hhmmss).rar
Here is the command I use:
rar a -r -k -m1 -p"password" -ep3 -x@exclude_list.txt -ag_yyyymmdd-hhmmss archive.rar @include_list.txt
As I was testing I found the problems discribed bellow that frustated my switch to 7z and kept me with rar.
Problem 1:
As the files lists from .txt files include files from multiple locations (including multiple drives), I need to use the switch -ep3 in rar to store the full paths including the drive letter. This is crutial because I need to know from here the files come from when I made the backup.
I couldn't achieve the same with 7z because I was unable to find any similar option in the 7z switches list. I tested 7z with <@listfiles...> option but no full paths were stored, so I ended up with a bunch of files and directories that didn't make much sense.
With rar we have the following switches:
ep Exclude paths from names
ep1 Exclude base directory from names
ep2 Expand paths to full
ep3 Expand paths to full including the drive letter
Problem 2:
As you may had notice in my rar command, I append the current date and time to the name of the archive for obvious reasons.
I also could not achieve this with 7z because I didn't found any switch that could allow me to do the same. But this time yes, I was able to append the date and time as I did with rar using the command date from CoreUtils (Windows version of date command sucks). But I think this feature should be implemented.
The rar switch that allows append current date and time no the archive name:
ag[format] Generate archive name using the current date
I think that for using 7z to make backup routines these features are extremelly importante and should be implemented.
Thank you,
Pedro Cunha
