Shell Programming and Scripting

Hi there,

I have more that 300 servers that I need to updated the comments field on /etc/passwd for users that have a blank comments fields. The users have accounts on different servers. I have created a list of these users on a text file called update_passwd.txt.

I need a script that will compare this file with /etc/passwd first backup the passwd database and update the comment field on /etc/passwd with the details on the text file if it's blank.

I have a script that I have created not sure if it will do the job as I have not worked a lot with scripts.

Below is my script and attached is my text file:

#!/usr/bin/bash
FILE1=/tmp/update_passwd.txt
FILE2=/etc/passwd
cp $FILE2 /etc/passwd.orig
for i in `cat $FILE1 | awk -F":" '{ print $2 }'`
do
FIELD1=`cat $FILE1 | grep ${i} |awk -F":" '{ print $3 }'`
grep $i ${FILE2}
if [ $? -eq 0 ]
then
usermod -c "${FIELD1}" $i
fi
done

I will highly appreciate your assistance.

Try this, the passwd file is updated with the awk command:

Code:

#!/usr/bin/bash

FILE1=/tmp/update_passwd.txt
FILE2=/etc/passwd
cp $FILE2 /etc/passwd.orig

awk 'BEGIN{FS=OFS=":"} NR==FNR{a[$2]=$3;next}
$1 in a && $5==""{$5=a[$1]} {print}' "$FILE1" "$FILE2" > passwd_new

mv passwd_new $FILE2

Regards

Thanks Franklin52 your script is working 100%.

Hi guys,

I'm experiencing problems after executing the script above from Franklin52. Please don't get me wrong the script is doing what it's suppose to do but it looks like it does not update the /etc/shadow or the finger information. I then get errors after running it e.g. when I login with any account on the server I get an error that ID cannot find name for user. When I copy the /etc/passwd.orig that the script backs up to /etc/passwd to fix the problem nothing is fixed until I execute chfn -f on a existing account like genlnx.

Please have a look at the errors below:

+-----------------------------------------------------------------------------+
genlnx@server1's password:
Last login: Tue Jan 6 13:07:06 2009 from 192.168.1.2
id: cannot find name for user ID 514
id: cannot find name for user ID 514
[I have no name!@server1 ~]$

To fix the problem need to execute the following command.

[root@server1 etc]# chfn -f genlnx
Changing finger information for root.
Finger information changed.
[root@server1 etc]#

I will highly appreciate your assistance.

Regards
The Duke

Don't log out of root.
Check permissions and ownership of /etc/passwd against another server. That script could change them.
Check syntax of /etc/passwd with "pwck".
Read "man pwconv" in the context of your machine, but don't run it unless you are really sure.
Overall it would be much much safer to use "usermod" to update the fields.

Hi Methyl,

I did use pwconv but did not fix the problem hance I ended up using chfn.
My first script is using usermod and this is not working and Franklin52 script is working except for this problem with finger information.

Can anyone assist me with a script or update Franklin52 script to incorporate usermod when updating the comments field.

The Duke will high appreciate your help.

Hi Guys,

May I please get help with this problem, I have been trying a lot of things and I'm not winning this script keeps deleting user account.I did it on a different server then used chfn but it did not solve the problem. Please help me I have 300 server that I need to update the comment field on and I'm desparate for this to work.

+-----------------------------------------------------------------------------+
genlnx@server2's password:
Last login: Tue Jan 10 16:07:06 2009 from 192.168.1.3
id: cannot find name for user ID 415
id: cannot find name for user ID 415
[I have no name!@server2 ~]$