[[$kernel!= linux[0-9][0-9]?([0-9])&&$kernel!="rmc"]]&& err "Invalid argument (use -h for help)."
[[$kernel!= linux[0-9][0-9]?([0-9])]]&& err "Please enter a valid kernel name."
[[$kernel!= linux[0-9][0-9]?([0-9])&&$kernel!= linux-rt-*manjaro &&$kernel!="rmc"]]&& err "Invalid argument.\nPlease choose one of the $(kernel_repo)\n"
[[$current=$kernel]]&& err "You can't reinstall your current kernel. Please use 'pacman -Syu' instead to update."
[[-z$(pacman -Ssq"^$kernel$")]]&& err "Please make sure if the given kernel(s) exist(s)."
[[-z$(pacman -Ssq"^$kernel$")]]&& err "Please make sure if the given kernel(s) exist(s).\n$(kernel_repo)\n"