Currently, the password is shown to anyone who can view the process list, e.g.
joe@dev:/home/joe# ps aux | grep 7z
root 24586 0.0 0.0 52796 1000 pts/1 S 18:20 0:00 /bin/sh /usr/local/bin/7za a -t7z -sihome.tar -psecret /var/backup/2010-10-04-dev-home-backup.tar.7z
root 24590 142 2.4 231512 197048 pts/1 Rl 18:20 20:18 /usr/local/lib/p7zip/7za a -t7z -sihome.tar -psecret /var/backup/2010-10-04-dev-home-backup.tar.7z
Would be great if there was a way to hide the password.
I've tried pipes and <<, but they don't seem to work, so I'm guessing the password isn't read from stdin.
I don't know how porting works, but I'm imagining sort of wrapper to supply a file name on the command line might also work (like --password-file=~/.7zpassword or something like that).