kuda.ai

How to log cron job outputs

Created on March 31, 2026 Updated on April 20, 2026

linux

This works on Ubuntu.

There are two layers to this problem:

1. see meta logs of cron
2. see the actual logs of the job

meta logs:

# either: /var/log/syslog
sudo grep 'CRON' /var/log/syslog | tail -10

# or alternatively: journalctl
journalctl -u cron

This will tell you that the scheduled cron job ran. It will not log anything from the command that ran.

Example:

2026-04-20T10:06:01.341918+02:00 mylinux CRON[300139]: (davidkuda) CMD (date >> /home/davidkuda/cron.log)

job logs:

You need to use redirection of STDOUT and STDERR. >> ~/logs/job.log 2>&1

Example:

* * * * * date >> /home/davidkuda/cron.log 2>&1

What is the arcane 2&1?

• >> append output to file
• /home/davidkuda/cron.log file path
• 2>&1 redirect STDERR (file descriptor 2) to file STDOUT (descriptor 1)
  • > redirect
  • 2 file descriptor 2 for STDERR
  • &1 file descriptor 1 for STDOUT

There is a very good explanation of this on StackOverflow.