New script to verify Alacritty upgrade

github/check.alacritty.update

@@ -0,0 +1,113 @@
+#!/bin/sh
+# Purpose {{{
+## Create a temp file (to monitor) if an upgrade is available for Alacritty
+## project on Github.
+## It's based on .deb package installation to check the current version.
+## It can also compare the current available version in APT repositories
+##   if "repo" is given as first argument.
+## How-to use {{{
+### 1. Needs releasetags script, in the same directory
+### cf. https://git.ipr.univ-rennes1.fr/cellinfo/scripts/src/master/github/releasetags
+# wget https://git.ipr.univ-rennes1.fr/cellinfo/scripts/raw/master/github/releasetags
+### 2. Create a cron job, eg :
+#00 20 * * * root /opt/repos/ipr.scripts/github/check.alacritty.update
+### 2-1 Create a cron job to compare the version available in a Debian repository :
+#00 20 * * * root /opt/repos/ipr.scripts/github/check.alacritty.update repo
+### 3. Monitor the temp file : /tmp/.github.alacritty.upgrade
+# Or enable MAILTO in cronjob and edit the script to print a message.
+# Or send a mail.
+# …
+## }}}
+# }}}
+
+# Expect maximum 1 argument {{{
+if [ $# -gt 1 ]
+then
+	cat << HELP
+
+check.alacritty.update    --
+Compare current version of an installed Alacritty and the last available.
+
+EXAMPLE :
+    - Compare the current version installed from .deb file
+        check.alacritty.update
+
+    - Compare the current version from apt's repository
+        check.alacritty.update repo
+
+HELP
+
+	exit 1
+fi
+# }}}
+
+# Vars {{{
+DEBUG=1
+
+script_wd=$(dirname "${0}")
+
+alacritty_repo_url="https://github.com/barnumbirr/alacritty-debian"
+
+if [ $# -eq 1 ] && [ "${1}" = "repo" ]  ## If repository's version should be compared
+then
+	alacritty_current_version=$(apt-cache policy alacritty | awk '/Candidate:/ {print $2}' | sed 's/.:\(.*\)-.*/\1/')
+else
+	alacritty_current_version=$(dpkg -l alacritty | awk '/^ii.*alacritty/ {print $3}' | sed 's/.:\(.*\)-.*/\1/')
+fi
+
+alacritty_new_version=$("${script_wd}"/releasetags "${alacritty_repo_url}" | head -n1 | sed 's/v//g')
+
+alacritty_new_version_file="/tmp/.github.alacritty.upgrade"
+alacritty_new_pkg_url="${alacritty_repo_url}/releases/download/v${alacritty_new_version}/alacritty_${alacritty_new_version}_amd64_unstable.deb"
+alacritty_tmp_pkg_path="/tmp/.alacritty_${alacritty_new_version}_amd64_unstable.deb"
+alacritty_new_pkg_path="/tmp/alacritty_${alacritty_new_version}_amd64_unstable.deb"
+# }}}
+
+# Check if the current version is the last one {{{
+if [ "${alacritty_current_version}" != "${alacritty_new_version}" ]; then
+	[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6s\e[m\n' "DEBUG : Test version — Current version (${alacritty_current_version}) and new one (${alacritty_new_version}) seems to be different."
+
+	## If it doesn't already exists, download this new package
+	if [ ! -f "${alacritty_new_pkg_path}" ]; then
+		[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6s\e[m\n' "DEBUG : Download .deb file from Alacritty repository on Github to: ${alacritty_new_pkg_path} ."
+		wget --quiet "${alacritty_new_pkg_url}" --output-document="${alacritty_new_pkg_path}"
+	fi
+
+else
+	[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6s\e[m\n' "DEBUG : Test version — The current version is up-to-date."
+	## Ensure to remove any temp file and useless .deb file
+	rm --force -- "${alacritty_new_version_file}" "${alacritty_new_pkg_path}" "${alacritty_tmp_pkg_path}"
+	## Exit
+	exit 0
+fi
+# }}}
+
+# Verify downloaded package {{{
+
+## If the downloaded package has a size greater than zero {{{
+if [ -s "${alacritty_new_pkg_path}" ]; then
+	[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6s\e[m\n' "DEBUG : Empty file ? — \
+Downloaded package looks good."
+	### Create a temp file to monitor
+	touch -- "${alacritty_new_version_file}"
+	printf '\e[1;35m%-6s\e[m\n' "An upgrade is available for Alacritty terminal (current : ${alacritty_current_version}) : ${alacritty_new_version}." >> "${alacritty_new_version_file}"
+
+	### Exit
+	exit 0
+else
+	[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6s\e[m\n' "DEBUG : Empty file ? — \
+Empty file, don't need to go further."
+	### Ensure to remove the file to monitor
+	rm --force -- "${alacritty_new_version_file}"
+
+	### Keep a record of the downloaded package because as a new release might come soon
+	mv --force -- "${alacritty_new_pkg_path}" "${alacritty_tmp_pkg_path}"
+
+	### Exit
+	exit 0
+fi
+## }}}
+
+# }}}
+
+exit 255