How to redirect cron job output to stdout

Question

I have a cron job and its output is now redirected into a file. It looks like the following

0 9 * * * /bin/sh /bin/cleanup.sh > /home/darkknight/cleanup.log

Answer 1

Running process has a PID and its fd (file descriptor) is mapping to /proc//fd. And we can find PID of the running cron process at /var/run/crond.pid.

To send cron log to stdout, we could write log to fd number 1 of the process started by cron.

0 9 * * * /bin/sh /bin/cleanup.sh > /proc/$(cat /var/run/crond.pid)/fd/1 2>&1