Welcome to Ubuntu 12.04 LTS (GNU/Linux 3.2.0-27-generic-pae i686)

 * Documentation:  https://help.ubuntu.com/

gcouldn't execute "sensors": no such file or directory
    while executing
"exec -- sensors | grep temp"
    invoked from within
"set temperature    [exec -- sensors | grep temp]"
    (file "/etc/motd.tcl" line 59)