Thanks - I tested it on my home email server which only has two shell users which also have mailboxes on postfix.
root:x:1:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/bin/sh
bin:x:2:2:bin:/bin:/bin/sh
sys:x:3:3:sys:/dev:/bin/sh
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/bin/sh
man:x:6:12:man:/var/cache/man:/bin/sh
lp:x:7:7:lp:/var/spool/lpd:/bin/sh
mail:x:8:8:mail:/var/mail:/bin/sh
news:x:9:9:news:/var/spool/news:/bin/sh
uucp:x:10:10:uucp:/var/spool/uucp:/bin/sh
proxy:x:13:13:proxy:/bin:/bin/sh
www-data:x:33:33:www-data:/var/www:/bin/sh
backup:x:34:34:backup:/var/backups:/bin/sh
list:x:38:38:Mailing List Manager:/var/list:/bin/sh
irc:x:39:39:ircd:/var/run/ircd:/bin/sh
gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/bin/sh
nobody:x:65534:65534:nobody:/nonexistent:/bin/sh
Debian-exim:x:100:102::/var/spool/exim4:/bin/false
statd:x:101:65534::/var/lib/nfs:/bin/false
identd:x:102:65534::/var/run/identd:/bin/false
carlos:x:1000:1000:Carlos Williams,,,:/home/carlos:/bin/bash
sam:x:1001:1001:Sam Williams,,,:/home/sam:/bin/bash
postfix:x:103:105::/var/spool/postfix:/bin/false
sshd:x:104:65534::/var/run/sshd:/usr/sbin/nologin
dovecot:x:105:107:Dovecot mail server,,,:/usr/lib/dovecot:/bin/false
spamd:x:5001:5001::/var/lib/spamassassin:/bin/nologin
ntp:x:106:108::/home/ntp:/bin/false
I ran the command & received the following:
Code:
swordfish:~# cat /etc/passwd | cut -d":" -f3 | grep '[0-9][0-9][0-9]' | wc -l
11