Как убрать лишний пробел?

echo /dev/$my_ip/test|tr -d " "

my_ip=$(hostname -I | tr -d ' ')

echo "/dev/${my_ip%% }/test"

int@blackhorse ~ 0 0.76 $ str="string_"
int@blackhorse ~ 0 0.70 $ echo "$str"
string_
int@blackhorse ~ 0 0.64 $ echo "${str::-1}"
string
int@blackhorse ~ 0 0.64 $

$man hostname
...
-I, --all-ip-addresses
              Display all network addresses of the host. This  option  enumerates  all  configured  addresses  on all network interfaces. The loopback interface and IPv6 link-local  addresses  are  omitted. Contrary to option -i, this option does not depend on name resolution. Do not make any assumptions about the order of the  output.