rpi-package-download: POSIX sh compatible

Signed-off-by: Richard Oliver <[email protected]>

Author: roliver-rpi

rpi-package-download/rpi-package-download

@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 
 set -e
 
@@ -20,12 +20,12 @@ RELEASE="${RELEASE:-bookworm}"
 ARCH="${ARCH:-arm64}"
 
 # Should be set by systemd
-SERVICE_NAME="rpi-package-download@$(systemd-escape ${REQUESTED_PACKAGE}).service"
+SERVICE_NAME="rpi-package-download@$(systemd-escape "${REQUESTED_PACKAGE}").service"
 CACHE_DIRECTORY="${CACHE_DIRECTORY:=/var/cache/${SERVICE_NAME}}"
 RUNTIME_DIRECTORY="${RUNTIME_DIRECTORY:=/run/${SERVICE_NAME}}"
 
 # Assume that [email protected] RUNTIME_DIRECTORY is available relative to our RUNTIME_DIRECTORY
-PACKAGES_FILE="${RUNTIME_DIRECTORY}/../fetch-repo-package-list@$(systemd-escape ${REPOSITORY}).service/Packages"
+PACKAGES_FILE="${RUNTIME_DIRECTORY}/../fetch-repo-package-list@$(systemd-escape "${REPOSITORY}").service/Packages"
 
 >&2 echo "Getting latest package information for ${REQUESTED_PACKAGE}"
 TMP_PKG_FILE="$(mktemp --tmpdir rpi-package-downloader.XXX)"
@@ -34,23 +34,23 @@ grep-dctrl \
 	--field=Package \
 	--exact-match "${REQUESTED_PACKAGE}" \
 	"${PACKAGES_FILE}" \
-	> ${TMP_PKG_FILE}
+	> "${TMP_PKG_FILE}"
 
 LATEST_DIR="${RUNTIME_DIRECTORY}/latest"
 LATEST_PKG_FILE="${LATEST_DIR}/Package"
 
-if cmp ${TMP_PKG_FILE} ${LATEST_PKG_FILE} 2>/dev/null; then
+if cmp "${TMP_PKG_FILE}" "${LATEST_PKG_FILE}" 2>/dev/null; then
 	>&2 echo "Package up-to-date; nothing to do"
 	exit
 fi
 
-CHKSUM=$(sha1sum ${TMP_PKG_FILE} | cut -d " " -f 1)
+CHKSUM=$(sha1sum "${TMP_PKG_FILE}" | cut -d " " -f 1)
 WORK_DIR="${CACHE_DIRECTORY}/${CHKSUM}"
-mkdir -p $WORK_DIR
+mkdir -p "$WORK_DIR"
 PACKAGE_FILE="${WORK_DIR}/Packages"
 mv "$TMP_PKG_FILE" "$PACKAGE_FILE"
 
-function get_dctrl_field() {
+get_dctrl_field() {
 	grep-dctrl \
 		--field=Package \
 		--exact-match "${1}" \
@@ -59,18 +59,18 @@ function get_dctrl_field() {
 		"${PACKAGE_FILE}"
 }
 
-PACKAGE_PARTIAL_URL="$(get_dctrl_field ${REQUESTED_PACKAGE} Filename)"
+PACKAGE_PARTIAL_URL="$(get_dctrl_field "${REQUESTED_PACKAGE}" Filename)"
 PACKAGE_FULL_URL="${REPOSITORY}/${PACKAGE_PARTIAL_URL}"
-PACKAGE_BASENAME="$(basename ${PACKAGE_PARTIAL_URL})"
+PACKAGE_BASENAME="$(basename "${PACKAGE_PARTIAL_URL}")"
 
 >&2 echo "Downloading package"
 curl \
 	"${PACKAGE_FULL_URL}" \
 	-o "${WORK_DIR}/${PACKAGE_BASENAME}" \
 	2> /dev/null
 
->&2 echo -n "Verifying package checksum: "
-pushd "${WORK_DIR}" > /dev/null
+>&2 printf "Verifying package checksum: "
+cd "${WORK_DIR}"
 grep-dctrl \
 	--field=Package \
 	--exact-match "${REQUESTED_PACKAGE}" \
@@ -79,7 +79,7 @@ grep-dctrl \
 	"${PACKAGE_FILE}" | sed 's/.*\///' | xargs > "${PACKAGE_BASENAME}.sha256"
 
 sha256sum --check "${PACKAGE_BASENAME}".sha256
-popd > /dev/null
+cd -
 
 >&2 echo "Updating symlinks"
 ln -sf "${WORK_DIR}/${PACKAGE_BASENAME}" "${WORK_DIR}/package.deb"