get-orig-tarball: download orig tarball for a package as read from debian/changelog

README.md

get-orig-tarball

Simply, this reads a debian/changelog file and downloads the orig tarball for that version. It allows building a package with debuild if you do not have the original source tarball. Such a case would likely occur if you had used git clone of a debian tree.

Usage

Usage: get-orig-tarball [ options ] [changelog [dir]]

   changelog: the changelog to parse.
   dir: place to put orig tarball. 
        default: dirname(changelog)/../../

   options:
      -O | --overwrite: overwrite an existing file 

get-orig-tarball

#!/bin/bash

VERBOSITY=0
TEMP_D=""
FORMATS=".tar.gz .tar.xz .tar.bz2"
DSC_BASE_URL="http://launchpad.net/ubuntu/+archive/primary/+files"

error() { echo "$@" 1>&2; }
fail() { [ $# -eq 0 ] || error "$@"; exit 1; }

Usage() {
    cat <<EOF
Usage: ${0##*/} [ options ] [changelog [dir]]

   changelog: the changelog to parse.
   dir: place to put orig tarball. 
        default: dirname(changelog)/../../

   options:
      -O | --overwrite: overwrite an existing file 
EOF
}

for_Usage() {
    cat <<EOF
Usage: ${0##*/} for [ options ] pkg pkg-version

   package: the source package
   version: the version of the package
   dir: place to put orig tarball.  default: .

   options:
      -O | --overwrite: overwrite an existing file 
EOF
}

for_bad_Usage() { for_Usage 1>&2; [ $# -eq 0 ] || error "$@"; return 1; }

bad_Usage() { Usage 1>&2; [ $# -eq 0 ] || error "$@"; return 1; }
cleanup() {
    [ -z "${TEMP_D}" -o ! -d "${TEMP_D}" ] || rm -Rf "${TEMP_D}"
}

debug() {
    local level=${1}; shift;
    [ "${level}" -gt "${VERBOSITY}" ] && return
    error "${@}"
}

get_field() {
    local clog="$1" field="$2" offset="$3" ret=""
    local out=""
    out=$(dpkg-parsechangelog \
        ${offset:+"--offset=$offset"} --show-field "$field" --count=1) || {
            ret=$?
            error "failed reading '$field' from '$clog'"
            return $ret
        }
    _RET="$out"
}

is_released() {
    [ "$1" != "UNRELEASED" -a "$1" != "unreleased" ]
}

get_dsc_url() {
    _RET="${DSC_BASE_URL}/${1}_${2}.dsc"
}

dir_has_orig() {
    local dir="$1" src="$2" ver="$3" n="" ext=""
    for ext in $FORMATS; do
        n="${src}_${ver}.orig${ext}"
        [ -f "$dir/$n" ] && _RET="$dir/$n" && return 0
    done
    return 1
}

for_main() {
    local short_opts="hOv"
    local long_opts="help,overwrite,verbose"
    local getopt_out=""
    getopt_out=$(getopt --name "${0##*/}" \
        --options "${short_opts}" --long "${long_opts}" -- "$@") &&
        eval set -- "${getopt_out}" ||
        { bad_Usage; return; }

    local cur="" next="" overwrite=false orig="" sdir="$PWD"
    local odir="."
    while [ $# -ne 0 ]; do
        cur="$1"; next="$2";
        case "$cur" in
            -h|--help) Usage ; exit 0;;
            -O|--overwrite) overwrite=true;;
            -v|--verbose) VERBOSITY=$((${VERBOSITY}+1));;
            --) shift; break;;
        esac
        shift;
    done

    local src="$1" ver="$2"
    [ $# -eq 2 -o $# -eq 3 ] || {
        for_bad_Usage "expected 2 or 3 args, got $#: $*";
        return
    }

    if [ $# -ge 3 ]; then
        odir="$3"
        [ -d "$odir" ] || { error "$odir: not a directory"; return 1; }
    else
        odir=$PWD
    fi

    local pver=""

    case "$ver" in
       upstream-*) ver="${ver#upstream-}"; uver=$ver; pver="not-provided";;
       *-*) 
          uver=${ver%-*}
          pver=${ver##*-};;
       *) uver="$ver"; pver="not-provided";;
    esac

    if [ "$pver" = "not-provided" ]; then
        debug 1 "downloading without a dsc, poking for $src and $ver"
        local ext="" name="" tname=""
        for ext in ${FORMATS}; do
            name="${src}_${ver}.orig$ext"
            tname="$name.tmp.$$"
            wget "${DSC_BASE_URL}/$name" -O "$odir/$tname" &&
                mv "$tname" "$odir/$name" &&
                { error "wrote ${name} to $odir"; return 0; } ||
                rm -f "$tname"
        done
        error "failed download of $src at $ver. tried orig formats $FORMATS"
        return 1
    else
        debug 1 "src=$src ver=$ver uver=$uver pver=$pver"
        dl_to_dir "$src" "$ver" "$odir" "$overwrite"
    fi
}

main() {
    local short_opts="hOv"
    local long_opts="help,overwrite,verbose"
    local getopt_out=""
    getopt_out=$(getopt --name "${0##*/}" \
        --options "${short_opts}" --long "${long_opts}" -- "$@") &&
        eval set -- "${getopt_out}" ||
        { bad_Usage; return; }

    local cur="" next="" overwrite=false orig="" sdir="$PWD"
    local changelog="debian/changelog" odir="" use_unreleased=false
    while [ $# -ne 0 ]; do
        cur="$1"; next="$2";
        case "$cur" in
            -h|--help) Usage ; exit 0;;
            -O|--overwrite) overwrite=true;;
            -v|--verbose) VERBOSITY=$((${VERBOSITY}+1));;
            --) shift; break;;
        esac
        shift;
    done

    [ $# -lt 3 ] || {
        bad_Usage "expected < 0, 1 or 2 args, got $#: $*";
    }

    if [ $# -ge 1 ]; then
        changelog="$1"
    fi
    if [ $# -ge 2 ]; then
        odir="$2"
        [ -d "$odir" ] || { error "$odir: not a directory"; return 1; }
    else
        odir=$(dirname "$changelog") &&
            odir=$(cd "$odir/../.." && pwd) ||
            { error "failed dirname for '$changelog'"; return 1; }
    fi

    local uver="" ver="" dist="UNRELEASED"
    while :; do
        get_field "$changelog" Version $offset && ver="$_RET" || return
        get_field "$changelog" Distribution $offset && dist="$_RET" || return
        get_field "$changelog" Source $offset && src="$_RET" || return
        uver=${ver%-*}
        pver=${ver##*-}
        [ "$unreleased" = "true" ] && break
        is_released "$dist" && break
        offset=$(($offset+1))
    done

    debug 1 "src=$src ver=$ver uver=$uver pver=$pver offset=$offset"
    dl_to_dir "$src" "$ver" "$odir" "$overwrite"
}

dl_to_dir() {
    local src="$1" ver="$2" odir="$3" overwrite=${4:-false} orig=""
    if dir_has_orig "$odir" "$src" "$uver"; then
        orig=${_RET}
        if ! $overwrite; then
            error "orig tarball existed at $orig. --overwrite to overwrite."
            return 0;
        fi
    fi

    get_dsc_url "$src" "$ver" || return
    dsc_url=$_RET
    debug 1 "dsc_url=$dsc_url"

    TEMP_D=$(mktemp -d "${TMPDIR:-/tmp}/${0##*/}.XXXXXX") ||
        fail "failed to make tempdir"
    trap cleanup EXIT

    cd "$TEMP_D"
    local vflag="--quiet"
    if [ "$VERBOSITY" -ge 1 ]; then
        vflag=""
    fi
    # unauthenticated is fine because we use https to launchpad
    dget $vflag --allow-unauthenticated --download-only "$dsc_url" ||
        fail "failed: dget --download-only $dsc_url"

    dir_has_orig "$TEMP_D" "$src" "$uver" || {
        error "dget succeeded, but no orig tarball found."
        cat "$TEMP_D/${src}_${ver}.dsc" 1>&2
        ls $TEMP_D 1>&2;
        return 1
    }
    orig="$_RET"

    cd "$sdir"
    mv "$_RET" "$odir/"
    _RET="${odir}/${orig##*/}"
    error "wrote $odir/${orig##*/}"
}

if [ "$1" = "for" ]; then
    shift
    for_main "$@"
else
    main "$@"
fi

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