Substitute tags generated from git for versioning purposes

version-substitute

#!/bin/bash
# Original code Copyright (c) 2018 Shane Celis[1]
# Licensed under the MIT License[2]
#
# Original code posted here[3].
#
# This comment generated by code-cite[4].
#
# [1]: https://github.com/shanecelis
# [2]: https://opensource.org/licenses/MIT
# [3]: https://gist.github.com/shanecelis/2dc391cde7c26773d6d14ca6825dc4fb
# [4]: https://github.com/shanecelis/code-cite

# version-substitute
# ==================
#
# Substitute tags generated from git for versioning purposes.

# Use Mustache[1] template written for bash called mo[2].
#
# [1]: https://mustache.github.io
# [2]: https://github.com/tests-always-included/mo

source "$HOME/bin/mo";
commentPrefix="${COMMENT:-//}";
tags=(majorminor semanticversion dotnetversion revision commitcount gitdescribe commithash versiontimestamp)
majorminor=`git describe --tags | perl -pe 's/^v(\d+)\.(\d+).*/$1.$2/g;'`;
revision=`git describe --tags | perl -pe 's/^v(\d+)\.(\d+)\.(\d+).*/$3/g;'`;
commitcount=`git rev-list --count HEAD`;
gitdescribe=`git describe --tags --long`;
commithash=`git rev-parse --short HEAD`;
semanticversion="${majorminor}.$revision";
dotnetversion="${majorminor}.$commitcount.$revision";
versiontimestamp=`date '+%Y-%m-%dT%H:%M:%S%Z'`;
if [ $# -ne 1 ]; then
   echo "Usage: $0 <template>" >&2;
   for tag in "${tags[@]}"; do
       echo "{{$tag}} -> ${!tag}";
   done
   exit 2;
fi

# Thanks for this read-only tip!
# https://projectgus.com/2009/07/marking-a-file-read-only-in-emacs-and-vim/
echo "$commentPrefix vim:set ro: -*- buffer-read-only:t -*-"
echo "$commentPrefix Warning: This file was procedurally generated from $1."

mo --fail-not-set $1
# The following code was required without mo.
# cat $1 |
# script=$(for tag in "${tags[@]}"; do
# 	           echo "s/\{\{$tag\}\}/${!tag}/g;";
#          done)
# cat $1 | perl -pe "$script"