CentOS - Oct 2008 - [OT] List of all email users

This is not CentOS-specific, hence OT.

I need a list of all email users on my system (there are hundreds of them).
The list could be extracted from /etc/aliases and the virtusertable.

Does anyone know of a script that would do this automatically? It would have
to 
- exclude commented-out lines (of course)
- exclude duplicates
- produce a list of usernames (or maybe unresolved email addresses for some
users) separated by a comma

I imagine perl would be the way to go. I haven't used perl at all myself.

Regards,
Jussi

--
Jussi Hirvi * Green Spot
Topeliuksenkatu 15 C * 00250 Helsinki * Finland
Tel. & fax +358 9 493 981 * Mobile +358 40 771 2098 (only sms)
jussi.hirvi at greenspot.fi * http://www.greenspot.fi

Jussi Hirvi wrote:
> This is not CentOS-specific, hence OT.
> 
> I need a list of all email users on my system (there are hundreds of them).
> The list could be extracted from /etc/aliases and the virtusertable.
> 
> Does anyone know of a script that would do this automatically? It would
have
> to 
> - exclude commented-out lines (of course)
> - exclude duplicates
> - produce a list of usernames (or maybe unresolved email addresses for some
> users) separated by a comma

for i in /etc/aliases /etc/postfix/virtual; do    
  cat $i | grep -Ev "(^#|^\s+$|^$)" | sed -e "s/://" | awk
'{print $1}' | \
  sort -u | tr \\n , 
done

Adapt to needs.

Ralph
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Ralph Angenendt (ra+centos at br-online.de) kirjoitteli (30.10.2008
17:12):
> for i in /etc/aliases /etc/postfix/virtual; do
> cat $i | grep -Ev "(^#|^\s+$|^$)" | sed -e "s/://" |
awk '{print $1}' | \
> sort -u | tr \\n ,
> done
> 
> Adapt to needs.
Thanks, that looks neat, and works.

For real-world use, I guess the source files (in my case aliases,
virtusertable) should be prepared first - the list will include unwanted
users like "bin" or "mysql", mailing list name defined in
virtusertable, and
possibly other strange things too.

- Jussi

--
Jussi Hirvi * Green Spot
Topeliuksenkatu 15 C * 00250 Helsinki * Finland
Tel. & fax +358 9 493 981 * Mobile +358 40 771 2098 (only sms)
jussi.hirvi at greenspot.fi * http://www.greenspot.fi

Jussi Hirvi wrote:
> This is not CentOS-specific, hence OT.
> 
> I need a list of all email users on my system (there are hundreds of them).
> The list could be extracted from /etc/aliases and the virtusertable.
> 
> Does anyone know of a script that would do this automatically? It would
have
> to 
> - exclude commented-out lines (of course)
and exclude "continuation" lines (lines starting with spaces).
> - exclude duplicates
> - produce a list of usernames (or maybe unresolved email addresses for some
> users) separated by a comma
why comma? isn't LF better (one user per line)?
> 
> I imagine perl would be the way to go. I haven't used perl at all
myself.
> 
you could start with something like

getkey()
{
   files=$*

   for file in $files; do
     sed -e '/^[\# 	]/d' -e '/^$/d' $file | \
       awk -F'[:         ]' '{print $1}'
   done
}

getkey /etc/aliases /etc/passwd | sort|uniq > users.local
getkey yourvirtualmap > users.virtual


If you want a list of all valid email addresses, you need to append the 
domains in mydestination to users.local.