deb-chklist

#!/usr/bin/env bash
#cito M:755 O:0 G:0 T:/usr/local/bin/deb-chklist
#------------------------------------------------------------------------------
# Project Name      - ShellProjects/source/deb-chklist
# Started On        - Mon 26 Jun 22:53:12 BST 2023
# Last Change       - Tue 27 Jun 11:28:55 BST 2023
# Author E-Mail     - terminalforlife@yahoo.com
# Author GitHub     - https://github.com/terminalforlife
#------------------------------------------------------------------------------
# For Debian- and Ubuntu-based distributions, scan '*.list' files for errors.
#
# Features:
#
# N/A
#
# Bugs:
#
# N/A
#
# Dependencies:
#
#   bash (>= 4.1)
#------------------------------------------------------------------------------

CurVer='2023-06-27'
Progrm=${0##*/}

Usage() {
	read -d '' <<-EOF
		Usage: $Progrm [OPTS] [FILE [FILE] ...]

		  -h, --help               - Display this help information.
		  -v, --version            - Output the version datestamp.
		  -C, --nocolor            - Disable ANSI color escape sequences.

		  The use of '--' to ignore proceeding options is supported.
	EOF

	printf '%s' "$REPLY"
}

Err() {
	printf 'Err: %s\n' "$2" 1>&2
	(( $1 > 0 )) && exit $1
}

NoColor=

BRed=$'\e[91m'
BYellow=$'\e[93m'
Reset=$'\e[0m'

Skip=
Args=()
while [[ -n $1 ]]; do
	case $1 in
		--)
			Args+=(--)
			Skip='True' ;;
		-[^-]*)
			if [[ $Skip == True ]]; then
				Args+=("$1")
			else
				Str=${1#-}
				Len=${#Str}
				for (( Index = 0; Index < Len; Index++ )); {
					Args+=(-"${Str:Index:1}")
				}
			fi ;;
		*)
			Args+=("$1") ;;
	esac
	shift
done

set -- "${Args[@]}"

while [[ -n $1 ]]; do
	case $1 in
		--)
			break ;;
		--help|-h)
			Usage; exit 0 ;;
		--version|-v)
			printf '%s\n' "$CurVer"; exit 0 ;;
		--nocolor|-C)
			BRed=
			BYellow=
			Reset= ;;
		-*)
			Err 1 'Incorrect option(s) specified.' ;;
		*)
			break ;;
	esac
	shift
done

OneFile=
Space='  '
if (( $# > 0 )); then
	Files=("$@")

	if (( ${#Files[@]} == 1 )); then
		OneFile='True'
		Space=
	fi
else
	Files=(/var/lib/dpkg/info/*.list)
fi

FileErr() {
	local FileArg=
	if [[ $1 == -f ]]; then
		FileArg='True'
		shift
	fi

	if [[ $FileArg == True ]]; then
		printf -v ErrorStr '%s%sFile%s %s.' "$Space"\
			"$BRed" "$Reset" "${1,}" 1>&2
	else
		printf -v ErrorStr '%sLine %s%d%s %s.' "$Space"\
			"$BRed" $LineNr "$Reset" "${1,}" 1>&2
	fi

	ErrorArr+=("$ErrorStr")

	(( ErrCount++ ))
	(( ErrCountThisFile++ ))
}

ErrCount=0
FileCount=0
for File in "${Files[@]}"; {
	[[ -f $File ]] || continue

	ErrorArr=()
	ErrCountThisFile=0
	(( FileCount++ ))

	Stat=$(stat --printf='%a %u %g\n' "$File")
	read Mode Owner Group <<< "$Stat"
	if [[ $Mode != 644 ]]; then
		FileErr -f "mode $Mode unexpected"
	fi

	(( Owner != 0 )) && FileErr -f "owner $Owner unexpected"
	(( Group != 0 )) && FileErr -f "group $Group unexpected"

	LineNr=0
	while read; do
		(( LineNr++ ))

		if [[ -z $REPLY ]]; then
			FileErr 'empty'
		elif [[ $REPLY == +([[:space:]]) ]]; then
			FileErr 'only spaces'
		elif [[ $REPLY == *//* ]]; then
			FileErr 'invalid path'
		elif [[ $REPLY != /* ]]; then
			FileErr 'relative path'
		fi
	done < "$File"

	if [[ -n "${REPLY:${#REPLY} - 1}" ]]; then
		FileErr -f 'missing final newline'
	fi

	if (( ErrCountThisFile > 0 )); then
		if [[ $OneFile != True ]]; then
			printf "* %s%s%s\n" "$BYellow" "${File##*/}" "$Reset"
		fi

		for Error in "${ErrorArr[@]}"; {
			echo "$Error"
		}
	fi
}

(( ErrCount > 0 )) && printf '\n'

if (( FileCount > 1 )); then
	printf 'Scanned %s%d%s file(s).\n'\
		"$BYellow" $FileCount "$Reset"
fi

if (( ErrCount > 0 )); then
	printf 'Found %s%d%s error(s).\n' "$BRed" $ErrCount "$Reset"

	exit 1
else
	printf 'No errors found.\n'
fi