This patch adds support for printing dots in place of the percentage indicator when compressing, similar to the zip command. The two new switches are -q (Quiet) and -dd (Display Dots), eg:
7za a -qdd200 foo.7z bar > progress.log
Will print 200 dots and nothing else to progress.log as it compresses. This is essential for being able to accurately monitor the compression progress using another program.
The default number of dots is 100.
Note: Quiet is only properly implemented for adding/updating and will have little effect on other operations.