generate_version.sh

#! /bin/sh

# Extract latest version and release date from ChangeLog.md and write to output file.

cl=$1
if [ -z "$cl" ]; then
    echo Error: Need the Change Log file as parameter one >&2
    exit 1
fi

vf=$2
if [ -z "$vf" ]; then
    echo Error: Need the output file name as parameter two >&2
    exit 1
fi

# Looking for '### major.minor.patch -- date'
#              $1  $2                $3 $4

recent=`egrep -m 1 -e '^### [[:digit:]]+\.[[:digit:]]+\.[[:digit:]]+ --' $cl`
if [ $? -ne 0 -o -z "$recent" ]; then
    echo "Error: Change Log $cl does not contain a semantic version line of '### major.minor.patch'" >&2
    exit 1
fi

set -- $recent
version=$2
date=$4

# Deduce project URL from go.mod
project=`grep ^module go.mod| head -1 | cut -f2 -d' '`
if [ $? -ne 0 -o -z "$project" ]; then
    echo Error: No module name found on go.mod >&2
    exit 1
fi

# Generate verion file in the approve gofmt format
(
    printf '// Code generated by "generate_version.sh"; DO NOT EDIT.\n'
    printf '// Generated on: %s\n\n' `date +%F`
    printf 'package main\n\nconst (\n'
    printf '\tName        = "fad"\n'
    printf '\tProject     = "go install %s"\n' "${project}@latest"
    printf '\tReleaseDate = "%s"\n' "${date}"
    printf '\tVersion     = "%s"\n' "${version}"
    printf ')\n\n'
    printf '// Code generated by "generate_version.sh"; DO NOT EDIT.\n'
) >${vf}