bin/mk-authors: Add script for updating AUTHORS.md file

If called without parameters it updates the authors file with new authors
since last release tag. With the -t option a specific tag can be specified.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>

bin/mk-authors

@@ -0,0 +1,135 @@
+#!/bin/bash
+#
+# mk-authors - Update the s390-tools authors file (AUTHORS.md)
+#
+# Invocation examples:
+#
+#  $ mk-authors
+#  $ mk-authors -t v2.0.0
+#
+# Copyright IBM Corp. 2017
+#
+# s390-tools is free software; you can redistribute it and/or modify
+# it under the terms of the MIT license. See LICENSE for details.
+
+cmd=$(basename $0)
+authors_file="AUTHORS.md"
+
+cleanup()
+{
+	test -f $authors_file_tmp && rm -f $authors_file_tmp
+}
+trap cleanup EXIT
+
+#
+# Print usage information
+#
+print_usage()
+{
+	cat <<EoUSAGE
+Usage: $cmd [-t LAST_GIT_TAG]
+
+Add all new authors since last release to the $authors_file file. Without
+the -t option the tool uses the last available git tag as last release.
+
+The tool should be called form the s390-tools master branch.
+
+OPTIONS
+-t, --tag LAST_GIT_TAG  Use git tag LAST_GIT_TAG as starting point
+-h, --help              Print this help, then exit
+EoUSAGE
+}
+
+#
+# Print help hint for option parsing error
+#
+print_parse_error_and_exit()
+{
+	echo "Try '$cmd -h' for more information." >&2
+	exit 1
+}
+
+#
+# Parse options
+#
+opts=$(getopt -o ht: -l help,tag: -n $cmd -- "$@")
+if [ $? != 0 ]; then
+	print_parse_error_and_exit
+fi
+# Use eval to remove getopt quotes
+eval set -- $opts
+while [ -n $1 ]; do
+	case $1 in
+	-h | --help)
+		print_usage
+		exit 0
+		;;
+	-t | --tag)
+		release_tag_last=$2
+		shift 2
+		;;
+	--)
+		shift
+		break
+		;;
+	*)
+		break
+		;;
+	esac
+done
+
+if [ $# != 0 ]; then
+	echo "$cmd: Invalid argument $1" >&2
+	print_parse_error_and_exit
+fi
+
+#
+# Get git root and last release tag
+#
+git_root=$(git rev-parse --show-toplevel 2> /dev/null)
+if [ $? -ne 0 ]; then
+	echo "$cmd: Use tool within s390-tools git repository" >&2
+	print_parse_error_and_exit
+fi
+authors_file_path=$git_root/$authors_file
+# Get last release tag if not specified via -t
+if [ -z $release_tag_last ]; then
+	tag_commit=$(git rev-list --tags --max-count=1)
+	release_tag_last=$(git describe --tags $tag_commit)
+fi
+# Verify release tag
+git show $release_tag_last &> /dev/null
+if [ $? -ne 0 ]; then
+	echo "$cmd: Cannot find tag '$release_tag_last'" >&2
+	print_parse_error_and_exit
+fi
+
+#
+# Update authors file
+#
+
+# Create temporary file for new author list
+authors_file_tmp=$(mktemp /tmp/authors.XXXXXX)
+
+echo "$cmd: Adding new authors since tag: $release_tag_last"
+{
+	# Print authors list without header
+	tail -n +4 $authors_file_path
+	# Add the new authors
+	git log --format="- %an" $release_tag_last..
+	# Then sort everything and remove duplicates
+} | sort | uniq > $authors_file_tmp
+# Create new AUTHORS file with header ...
+cat <<EoHEADER > $authors_file_path
+List of all individuals having contributed content to s390-tools
+----------------------------------------------------------------
+
+EoHEADER
+# ... and add new content
+cat $authors_file_tmp >> $authors_file_path
+
+cat <<EoUPDATE_MSG
+ - Updated file: $authors_file_path
+ - Verify changes with: git diff $authors_file_path
+ - Do a manual *cleanup* before commiting if necessary.
+EoUPDATE_MSG