[pacman-dev] pac-file utility script

[pete morris]

On Thu Jun 26, 2008 at 10:07AM, Allan McRae wrote:
> Hi Pete,
> 
> Can you post the script inline so it would be easier for us to comment 
> on.

Sure, see below:

#!/bin/bash

#-----------------------------------------------------------
# A utility for discovering which ArchLinux package contains 
# a given file. Downloads filelists for all active repos in
# pacman.conf; uses mirrors in order according to pacman's
# mirrorlist file.
#
# Peter Morris 2008
#-----------------------------------------------------------

db=/var/lib/pacman/filelists
pacmanconf=/etc/pacman.conf
mirrorlist=/etc/pacman.d/mirrorlist

#-----------------------------------------------------------
# Print active repos in $pacmanconf.
#-----------------------------------------------------------
function list_repos() {
    sed -n '/REPOSITORIES/,$ s/^\[\(.*\)\]/\1/p' $pacmanconf
}

#-----------------------------------------------------------
# Print active mirrors in $mirrorlist.
#-----------------------------------------------------------
function list_mirrors() {
    sed -n 's/^Server = \(.*\)$/\1/p' $mirrorlist
}

#-----------------------------------------------------------
# Download the filelist for repo $1. Assumes $mirrors
# is an array of urls to check for $file.
#-----------------------------------------------------------
function download() {
    repo=$1
    file="${repo}.files.tar.gz"

    i=0
    while [[ ! -e "${db}/${file}" ]]; do
        if (( $i >= ${#mirrors[@]} )); then
            return 1
        fi

        url=$(echo "${mirrors[$i]}" | sed "s/\$repo/$repo/g")
        wget --connect-timeout=15 -P "$db" "${url}/${file}"
        let i+=1
    done
}

#-----------------------------------------------------------
# Decompress $1 into dir $2.
#-----------------------------------------------------------
function decompress() {
    file=$1
    repo=$2

    mkdir "${db}/${repo}"
    tar -xzf "${db}/${file}" -C "${db}/${repo}"
    rm -f "${db}/${file}"
}

#-----------------------------------------------------------
# Download the filelist for each active repo in 
# pacman.conf. Tries mirrors in order until successful.
#-----------------------------------------------------------
function sync() {
    mirrors=($(list_mirrors))
    for repo in $(list_repos); do
        echo "Fetching filelist for $repo"
        download "$repo"
        if [[ $? == 0 ]]; then
            decompress "$file" "$repo"
        else
            echo
            echo "Error: unable to retrieve $file from any mirror."
            echo
        fi
    done
}

#-----------------------------------------------------------
# Print usage message.
#-----------------------------------------------------------
function usage() {
    echo "usage: $(basename $0) [options] [pattern]"
    echo echo "Search package filelists for [pattern]."
    echo "options:"
    echo "  $(basename $0) [-h --help]      Print this help message."
    echo "  $(basename $0) [-S --sync]      Syncronize package filelists."
}

#-----------------------------------------------------------
# Start of `main'.
#-----------------------------------------------------------
case "$1" in
    -S|--sync)
        if [[ $EUID != 0 ]]; then
            echo "error: you cannot perform this operation unless you are root."
            exit 1;
        fi    

        echo "Syncronizing ${db}..."; echo
        rm -rf "$db" && mkdir -p "$db"
        sync
    ;;

    -h|--help)
        usage
    ;;
    *)
        if [[ $# < 1 ]]; then
            echo "not enough parameters"; echo
            usage
            exit 1
        fi

        if [[ ! -d "$db" ]]; then
            echo "File database \"$db\" does not exist!"
            echo "Have you synchronized the database?"
            echo
            exit 1
        fi

        grep -rE "$@" "$db" | sed  "s|$db/\(.*\)/files:|\1 |g"
    ;;
esac