Hi, I would like to append a parameter "transparent_hugepage=never" to the below regex matched line in-between the quotes. On subsequent runs the substitution should be ignored to maintain idempotence (run as an Ansible playbook task). I tried a few things but failed as my knowledge is very limited. Thank you for your help and pardon my poor articulation. Line in question:

GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=centos/root rd.lvm.lv=centos/swap rhgb quiet"

The sed keeps appending after repeating the play as I can't get the negative lookahead assertion to work, I think that's what it is?

sed '/^GRUB_CMDLINE_LINUX=.*/ s/\(.*\)"/\1 transparent_hugepage=never"/' $line

And this from the playbook appends after the last quote breaking the config: 

                                                                      
+    
replace:                                                              
+          
backup: yes                                                           
+          
dest: /etc/default/grub                                               
+          
regexp: '(^GRUB_CMDLINE_LINUX(?!.*\btransparent_hugepage=never\b).*)$'
+          
replace: '\1 transparent_hugepage=never"'

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In reply to GRUB Append Parameter in-between Quotes by ephemeric

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