Note que você precisará de execp ou execpi para fazer o acima como exec e execi não analisar a saída do script
execp: Executes a shell command and displays the output in conky. warning: this takes a lot more resources than other variables. I'd recommend coding wanted behaviour in C and posting a patch. This differs from $exec in that it parses the output of the command, so you can insert things like ${color red}hi!${color} in your script and have it correctly parsed by Conky. Caveats: Conky parses and evaluates the output of $execp every time Conky loops, and then destroys all the objects. If you try to use anything like $execi within an $execp statement, it will functionally run at the same interval that the $execp statement runs, as it is created and destroyed at every interval.
Isso também funciona simplesmente com um arquivo como:
${execpi 15 cat /path/to/file.log}