Cron job stderr to email AND log file?

Question

I have a cron job:

$SP_s/StartDailyS1.sh >$LP_s/MirrorLogS1.txt

Where SP_s is the path to the script and LP_s

Answer 1

I think the solution would be:

$SP_s/StartDailyS1.sh 2>&1 >> $LP_s/MirrorLogS1.txt | tee -a $LP_s/MirrorLogS1.txt

This will:

• append standard output to $LP_s/MirrorLogS1.txt
• append standard error to $LP_s/MirrorLogS1.txt
• print standard error, so that cron will send a mail in case of error

Answer 2

Since I was just looking at the info page for tee (trying to figure out how to do the same thing), I can answer the last bit of this for you.

This is most of the way there:

(( my_command 3>&1 1>&2 2>&3 ) | tee error_only.log ) > all.log 2>&1

but replace "error_only.log" with ">(email_command)"

(( my_command 3>&1 1>&2 2>&3 ) | tee >(/bin/mail -s "SUBJECT" "EMAIL") ) > all.log 2>&1

Note: according to tee's docs this will work in bash, but not in /bin/sh. If you're putting this in a cron script (like in /etc/cron.daily/) then you can just but #!/bin/bash at the top. However if you're putting it as a one-liner in a crontab then you may need to wrap it in bash -c ""

Answer 3

Unless I'm missing something:

command 2>&1 >> file.log | tee -a file.log

2>&1 redirects stderr to stdout

>> redirects regular command stdout to logfile

| tee duplicates stderr (from 2>&1) to logfile and passes it through to stdout be mailed by cron to MAILTO

I tested it with

(echo Hello & echo 1>&2 World) 2>&1 >> x | tee -a x

Which indeed shows World in the console and both texts within x

The ugly thing is the duplicate file name. And the different buffering from stdout/stderr might make text in file.log a bit messy I guess.