[CLUE-Cert] scripting fun

[jdlabarnhart at home.com]

Hello all,

When I setup a sysad class I make groups us, them, exclusiv and secret.
I need to add students to the us and exclusiv groups. I do this by using
a "for" loop.

for User in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
do
usermod -G us,exclusiv s$User
done

A simple 4 line script. Now what I would like to do is get rid of the 1
2 3 ... line of the for loop and do something like

cat /etc/password | xargs grep s* 
for User in $SUser
do
usermod -G us,exclusiv s$User
done

I know what the users are but would like to automate the process a
little more. There are goals that need to be met.

1. Small script. 5 -10 lines at max. make it easy to remember.
2. Done in memory. While we could do this with temp files we want to do
this without. makes it more fun.

Why would we do something like this? How about that a development group
is put together to do some work. They will work on project X and will
need to access the same documents. 





/etc/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:
daemon:x:2:2:daemon:/sbin:
adm:x:3:4:adm:/var/adm:
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
operator:x:11:0:operator:/root:
ftp:x:14:50:FTP User:/var/ftp:
sympa:x:89:89:Sympa Mailing list manager:/var/lib/sympa:/bin/bash
nobody:x:99:99:Nobody:/:
alias:x:400:401:qmail alias user:/var/qmail/alias:/bin/true
s1:x:501:501::/home/s1:/bin/bash
s2:x:502:502::/home/s2:/bin/bash
s3:x:503:503::/home/s3:/bin/bash
s4:x:504:504::/home/s4:/bin/bash
s5:x:505:505::/home/s5:/bin/bash

/etc/group
root:x:0:root
bin:x:1:root,bin,daemon
daemon:x:2:root,bin,daemon
sys:x:3:root,bin,adm
adm:x:4:root,adm,daemon
tty:x:5:
disk:x:6:root
lp:x:7:daemon,lp
mem:x:8:
kmem:x:9:
wheel:x:10:root
us:x:401:
them:x:402:
excluciv:403:
secret:404:
s1:x:501:
s2:x:502:
s3:x:503:
s4:x:504:
s5:x:505: