Shell Programming and Scripting

Hello everyone, i hope someone can help me, i am a complete noob at bash so plse be gentle,
What i want to do is add a line under a line in a file, the file is xorg.conf and the line i would like to add is Option "SHMConfig" "on" under the line Option "Emulate3Buttons" "yes"
what i have found is below but i dont know how to add the params line to find and add and file to edit
Thankyou in advance if anyone can help me

You can use sed's append option:

sed -i.bak '/Option "Emulate3Buttons" "yes"/a\Option "SHMConfig" "on"' xorg.conf

Replace the sed script inside your bash script with the one given here...

Code:

sed '/Option "Emulate3Buttons" "yes"/a\
Option "SHMConfig" "on"
' $file

Thank you so much, just what i wanted

I almost have it thank you so much i am much closer, the problem is that it wont write the line, if i put it to write under a normal line ie without the spaces etc it works but not for the line i want, i have double checked spelling etc even copied paste the line etc, i think the spacings or something is messing it up, hope i have explained it right.

solved it after a bit of trial and error it was just spacing, thank you,thank you,thank you,thank you,thank you,thank you,thank you,thank you,thank you,thank you,thank you,thank you,thank you,thank you,thank you,thank you,thank you,thank you,