quick sed question

BrianK · 09-16-2009, 05:33 PM

I need to edit the sudo file on lots of machines. I figure the easiest way is to run a for loop to ssh to each box, sed the sudoers file to a new file & copy/move back over the top of the original (and of course, change permissions accordingly)

The problem is, I'm not sure how to add a line after a match with sed.

So if my file looks like:

Code:

# comments

root    ALL=(ALL) ALL
briank  ALL=(ALL) ALL
other   ALL=(ALL) ALL

# more comments

I'd like it to add the new sudoer after "other" so the file looks like:

Code:

# comments

root    ALL=(ALL) ALL
briank  ALL=(ALL) ALL
other   ALL=(ALL) ALL
newguy  ALL=(ALL) ALL

# more comments

I'm open to other solutions if this doesn't seem reasonable (other solutions that result in one new user having sudo privs - not everyone in a group or something like that.

)

jschiwal · 09-16-2009, 06:36 PM

You simply need to match the pattern of the 'other' line and add the new line:

Code:

sudo sed -i '/^other/a\
newguy\tALL=(ALL) ALL' /etc/sudoers

ghostdog74 · 09-16-2009, 07:22 PM

by "adding", the basic mechanism can be just printing . eg

Code:

awk '/^other/{print;print "new value";next}1' file > temp; mv temp file