Re: [Help-bash] Email output + logging too?

[Greg Wooledge]

On Sat, Sep 14, 2013 at 09:15:58AM +0100, Sharon Kimble wrote:
> I have this script which uses obnam to back up my /home/$USER
> directory, and it outputs to 2 logs, and should also output to an
> email. 
> =======================================
> LOGFILE="/home/boudiccas/logs/obnam.txt"
> LOGGING2="/home/boudiccas/cron/du.txt"
> ####################################################
> notify-send "Starting main backup..."
> 
> obnam backup
> 
> if [ "$?" -ne 0 ]; then
>   notify-send "Unable to finish main backup."
>   exit 1
> else
>   notify-send "Finished main backup."
>   
>   du -sh /media/boudiccas/backup/obnam-home>>$LOGGING2 2>&1
>   
> echo 'Sending Backup report : Backup of obnam-home completed', $(date
> -R) 'logged to'>>$LOGFILE 2>&1
> 
> fi
> ==============================================
> As shown it just outputs to the logs but not the email.

Nothing in this script explicitly invokes a mail user agent.  If this
is being run from a crontab, then the script's standard output and
standard error will automatically be emailed to someone (typically the
owner of the crontab).

So, I believe that your question really boils down to "How do I cause
all of my script's output to be sent to a logfile *and* also to stdout?"

Matthew's suggestion to put "tee -a" on every line that generates output
is one solution to this.  However, it's tedious and inefficient.

Another solution is to set up a single redirection at the start of the
script:

#!/bin/bash

# Log all stdout+stderr 
exec > >(tee -a /home/boudiccas/logs/obnam.txt) 2>&1

# The rest of your script goes here.

This is covered in more detail at http://mywiki.wooledge.org/BashFAQ/106