topic Re: gawk command in Operating System - Linux

gawk command

Ragni Singh — Thu, 11 Aug 2005 14:51:40 GMT

Hi all, can you please help me with a one liner in gawk that says chnage the /etc/shadow password field from a password to just a *.

thanks and points will be assigned.

Currently /etc/shadow looks like this...

odaos:$1$0rP21yM.$.NsFDQTtnnu7GE5qs84D/0:12492:0:99999:7:::

I want the 2nd field to be like such "*".

Re: gawk command

Stuart Browne — Thu, 11 Aug 2005 15:58:44 GMT

You actually want to modify the '/etc/shadow' file? or just a display of it with the password masked ?

If the first, then don't use awk, as it will require a temporary file and a move.

If you want to lock an account, then use the 'passwd -l ' command. This prefix's the encrypted password with an '!' which makes it invalid.

If it's just for displaying on the screen, then use something like:

awk 'BEGIN {FS=":";OFS=FS}{$2 = "*";print}' /etc/shadow

FS = field separator, OFS = output field separator.

Re: gawk command

Muthukumar_5 — Fri, 12 Aug 2005 00:58:06 GMT

You can try as,

perl -ni -e '@a=split /:/;$a[1]="*";$,=":";print @a;' /etc/shadow

Note: It will automatically change /etc/shadow file also. So try to backup /etc/shadow file as /etc/shadow.org

hth.

Re: gawk command

Ragni Singh — Fri, 12 Aug 2005 09:37:30 GMT

thanks but I still didn't get the answer I am looking for. Currently my /etc/shdow file has the password entry. I want to chnage this field to just a "*". This way users will be forced to authenticate to windows. I don't want a password in the 2nd field, I want a star * in that field.

Re: gawk command

Ivan Ferreira — Fri, 12 Aug 2005 10:01:47 GMT

Why don't you just use the usermod -L command to lock the users accounts?

Anyway, try this:

awk -F ":" -v OFS=":" '$2="*" { print $0 }' /etc/shadow