A common practice when adding entries to crontab is to end the entry like this:
The purpose of this is to suppress any output from the command itself, because we’re not interested. I picked up this syntax years ago because it just works, but I never knew what the
2>&1 actually meant, until today.
The first part:
STDOUT (the standard output stream) to
/dev/null (which is basically a blackhole for bits). That’s easy enough.
The second part:
STDERR (standard error stream) to the same place as
STDOUT (which was just specified).
STDOUT has the assigned number 1 and
STDERR has the assigned number 2.
This way both
STDOUT (1) and
STDERR (2) are directed to
/dev/null and all output of the cronned command is suppressed.