an easy way to set variables in config files
Usage Example:
perl ./confset.pl example.conf setting=value
if your separator is "(double quotation mark) you need to do it like so
variable=""net.ifnames=0 biosdevname=0"" /path/to/file
i.e sudo perl src/confset.pl GRUB_CMDLINE_LINUX=""net.ifnames=0 biosdevname=0"" /etc/default/grub