Bash 101 Help Please

[Matt Graham]

From: Lisa Kachold
[snip]
> Would this work to append to the line [containing 'unique']:
> sed -e 's/unique/ $username/' /etc/samba/smb.conf

In ./smb.conf :

[fred]
valid users = unique fred
# end ./smb.conf

mallory:~$ username=JOEBOB
mallory:~$ sed -e 's/unique/ $username/' smb.conf
[fred]
valid users =  $username fred
# end smb.conf
mallory:~$ sed -e "s/unique/ $username/" smb.conf
[fred]
valid users =  JOEBOB fred
# end smb.conf

...things in '' aren't subject to bash variable expansion, and running sed on
a file will send that file to stdout.  As I wrote in my message to PLUG at
12:35pm today, you probably want something like:

sed -e "s/\(.*valid users.*\)/\1 $username/" -i /etc/samba/smb.conf

...which will edit -in-place /etc/samba/smb.conf so that $username is appended
to lines that contain "valid users".

-- 
Matt G / Dances With Crows
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