search a dir and list all debian packages that own those path

dpkg-search-owner.sh

#!/usr/bin/env bash

# exit on unbound variable
set -u

# enable colors if appropriate
if [[ -t 1 && -z "${NO_COLOR-}" && "${TERM-}" != "dumb" ]]; then
    # ANSI colors
    NC='\033[0m' # no color
    RED='\033[1;31m'
    GREEN='\033[0;32m'
else
    NC=""
    RED=""
    GREEN=""
fi

echo_stderr() {
    echo "$@" >&2
}

echo_error() {
    printf "${RED}Error${NC}: %b\n" "$@" >&2
}

usage_exit() {
    filename=$(basename $0)
    echo_stderr "Usage: $filename <DIRECTORY> [MAX_DEPTH=1]"
    echo_stderr "Example: $filename /etc/apt/"
    exit 1
}

# check if DIRECTORY was provided
if [ $# -lt 1 ]; then
    usage_exit
elif [ $# -gt 2 ]; then
    echo_error "Unknown argument: ${@:3}"
    usage_exit
fi

SEARCH_DIR=$(realpath --no-symlinks "$1")

# check if directory exists
if [ ! -d "$SEARCH_DIR" ]; then
    echo_error "'$SEARCH_DIR': not a directory"
    usage_exit
fi

# check if MAX_DEPTH was provided
MAX_DEPTH=1
if [ $# -ge 2 ]; then
    # check if MAX_DEPTH is an integer >= 1
    if ! [[ "$2" =~ ^[0-9]+$ ]] || [ "$2" -lt 0 ]; then
        echo_error "MAX_DEPTH must be an integer >= 0"
        usage_exit
    else
        MAX_DEPTH="$2"
    fi
fi

# get all paths as arg1 arg2 argN
# then give it to dpkg-query
mapfile -t list_paths < <(find "$SEARCH_DIR" -maxdepth "$MAX_DEPTH" -print 2>/dev/null)

# in my tests, dpkg returnes in the same order as input args
mapfile -t list_dpkg_output < <(dpkg-query --search "${list_paths[@]}" 2>&1)

for idx in "${!list_paths[@]}"; do
    path=${list_paths[idx]}
    line=${list_dpkg_output[idx]}

    # make sure both list items are matched
    if [[ "$line" != *"$path"* ]]; then
        echo_error "BUG: path is not in line"
        echo_stderr "path=$path"
        echo_stderr "line=$line"
        exit 1
    fi

    # for cleaner output
    relative_path=$(realpath -e --no-symlinks "$path")

    pkg_names=$(echo "$line" | awk -F ": " '{print $1}')
    pkg_color="$GREEN"

    # means error
    if [[ "$pkg_names" == "dpkg-query" ]]; then
        error_msg=$(echo $line | awk -F ": " '{print $2}' | awk -F "$path" '{print $1}')
        pkg_names="NONE"
        pkg_color="$RED"
    fi

    printf "${pkg_color}%s${NC} | %s\n" "$pkg_names" "$relative_path"
done