Comment 2 for bug 258799

More accurate description:

kdesu.distrib -c 'printf "ControlPort 9051\n" >> /etc/tor/torrc' - WORKS
kdesudo -c 'printf "ControlPort 9051\n" >> /etc/tor/torrc' - DOES NOT WORK

The latter gives:

passprompt
ControlPort 9051
printf: warning: ignoring excess arguments, starting with `>>'

and nothing gets written to /etc/tor/torrc.

The command displayed in the kdesudo dialog is:

printf 'ControlPort 9051\n' '>>' '/etc/tor/torrc'

so each element of the command is being treated as a separate command.