deb-prepare.sh

#!/bin/bash

# Prepares debian directory before dpkg-buildpackage can be run.
#
# Arguments:
#     $1 = customer (only for customized build)
#     $2 = debian release, i.e. distribution name

DEB_CUSTOMER=$1
DEB_RELEASE=$2

# forces symlink, no special case handling
function link() {
    ln -sfT $1 debian;
}

# expands template from debian/templates
function expand_template() {
    template="${1}"
    base=$(basename "${template}" .template)
    dst="debian/${base}"

    shift
    declare -a srcs
    for variant in "${@}"; do
        srcs+=("debian/${variant}/${base}")
    done

    src=""
    for candidate in ${srcs[@]}; do
        if test -f "${candidate}"; then
            src="${candidate}"
            break
        fi
    done

    if test -z "${src}"; then
        echo "There is no source file ${srcs[@]} to fill in data in template ${template}." >/dev/stderr
        exit 1
    fi

    header="${src}.header"
    footer="${src}.footer"

    (
        # we are using {{{ and }}} to quote text in M4 macros these trigraphs
        # are probably not expected to be in sane text
        echo "m4_changequote({{{,}}})m4_dnl"

        # include source file, with variable (i.e. macro) definitions
        echo "m4_include(${src})m4_dnl"

        echo "m4_define({{{DEB_RELEASE}}},{{{${DEB_RELEASE}}}})m4_dnl"
        echo "m4_define({{{DEB_CUSTOMER}}},{{{${DEB_CUSTOMER}}}})m4_dnl"
        echo "m4_define({{{DEBIAN_VERSION_SUFFIX}}},{{{${DEBIAN_VERSION_SUFFIX}}}})m4_dnl"

        # output:

        # add specialized header template if exists
        test -f "${header}" && echo "m4_include(${header})m4_dnl"
        # template itself
        echo "m4_include(${template})m4_dnl"
        # add specialized footer template if exists
        test -f "${footer}" && echo "m4_include(${footer})m4_dnl"
    ) | m4 ${DEB_TEMPLATE_MACROS} -P -  > "${dst}"
}

# expands all templates from debian/templates
function expand_templates() {
    echo "*** Expanding debian templates for releases <${@}>." >/dev/stderr
    for template in $(compgen -G "debian/templates/*.template"); do
        expand_template "${template}" "${@}"
    done
}

# Symlink? Make room for possible different destination.
if /usr/bin/test -h debian; then
    rm debian
fi

# Symlinking
if ! test -d debian; then
    # no debian dir, we have to symlink

    # check all possible release-based variants
    VARIANTS="${DEB_CUSTOMER}.${DEB_RELEASE} ${DEB_RELEASE} ${DEB_CUSTOMER}"

    for variant in ${VARIANTS}; do
        path="debian.${variant}"
        if test -d "${path}"; then
            echo "*** Using debian directory ${path}." >/dev/stderr
            link "debian.${variant}"
            break
        fi
    done
else
    echo "*** Using plain debian directory." >/dev/stderr
fi

# Template expansion; only if there is any template
if test -d debian/templates; then
    expand_templates "${DEB_RELEASE}" any
fi