Question

I am trying to let my makefile setup a cronjob for my application. Unfortunately it appears to not be working as the $CRONENTRY variable seems to be empty. What am I doing wrong here?

addcron:
    CRONENTRY="*/2 * * * * /usr/bin/node cronapp.js >> logfile.log"
    crontab -l | { cat; echo ${CRONENTRY}; } | crontab -

Answer 1

Each command in a rule executes in its own subshell; variables do not survive from one command to the next. So if you want to use a variable this way, you have to string the commands together.

addcron:
    CRONENTRY="whatever" ; \
  do_something_with $(CRONENTRY)