linux-kernel - Re: [PATCH] scripts:prune-kernel:prune kernel and modules dir from the system

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Date:   Tue, 29 Oct 2019 17:05:23 -0700
From:   Randy Dunlap <rdunlap@...radead.org>
To:     Bhaskar Chowdhury <unixbhaskar@...il.com>, bfields@...ldses.org
Cc:     yamada.masahiro@...ionext.com, michal.lkml@...kovi.net,
        linux-kbuild@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] scripts:prune-kernel:prune kernel and modules dir from
 the system

Hi,

On 10/28/19 8:00 PM, Bhaskar Chowdhury wrote:
> This patch will remove old kernel and modules directory from 
> the system interactive way and also at once ,provied the parameter
> given to the invoking script.
> 
> Signed-off-by: Bhaskar Chowdhury <unixbhaskar@...il.com>
> ---
>  scripts/prune-kernel | 58 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 58 insertions(+)
> 
> diff --git a/scripts/prune-kernel b/scripts/prune-kernel
> index 58a7650ce592..a6c990450ddc 100755
> --- a/scripts/prune-kernel
> +++ b/scripts/prune-kernel
> @@ -1,2 +1,60 @@
>  #!/bin/bash
>  # SPDX-License-Identifier: GPL-2.0
> +#This script will delete old kernels and modules directory related to it,both
> +#automated and interactive way, if you choose -i or --interactive as parameter.
> +#For normal operation you have to invoke this script like below
> +#prune-kernel -r kernel_ver modules_dir_name
> +flag=$1
> +kernel_ver=$2
> +modules_dir_name=$3
> +boot_dir=/boot
> +modules_dir=/lib/modules
> +
> +remove_old_kernel() {
> +	cd $boot_dir
> +	rm -If vmlinuz-$kernel_version System.map-$kernel_version config-$kernel_version
> +	return 0
> +}
> +
> +remove_old_modules_dir() {
> +	cd $modules_dir
> +	rm -rf $modules_version
> +	return 0
> +}
> +
> +usage() {
> +	printf "Usage: $(basename $0) [-ri] \n"
> +	printf "\n -r | --remove kernel_ver modules_dir_name \n"
> +	printf "\n -i | --interactive use as interactive way \n"
> +}
> +
> +while getopts :hir opt;do

what is the purpose of "opt" above?
It is not used AFAICT.

My internet searching says that 'getopts' does not support "--options" (long options).
But then $flag is used below, not $opt, so the long options are just supported
by "flag=$1" at the beginning of the script.


> +	case "$flag" in
> +		-i | --interactive)
> +			printf "\nEnter kernel version to remove or blank/empty to exit:%s"
> +			read kernel_version
> +			if [[ $kernel_version != "" ]]; then
> +				remove_old_kernel
> +				printf "Please give the full modules directory name to remove:%s"
> +				read modules_version

Need to handle modules_version = "" here.

> +				remove_old_modules_dir
> +				printf "\n\n\n Removed kernel version:$kernel_version and associated modules directory:$modules_version ..Done.\n"
> +			else
> +				exit 1
> +			fi
> +			;;
> +		-h | --help)
> +			usage
> +			exit 1
> +			;;
> +		-r | --remove)

What happens if a user enters:

./scripts/prune-kernel -r
and no kernel_ver or modules_dir_name after -r?


> +			shift $(( OPTIND -1 ))

What is the purpose of the 'shift' since there is no loop to process more options?

> +			cd $boot_dir
> +			rm -f $kernel_ver
> +			cd $modules_dir
> +			rm -rf $modules_dir_name
> +			printf "Removed kernel version:$kernel_ver and modules directory:$modules_dir_name from the system. \n\n"
> +			exit 0
> +			;;
> +	esac
> +done

This patch does not delete the original script loop, so that still follows
after the 'done' above.  Was that intentional?

-- 
~Randy