diff --git a/.gitignore b/.gitignore
index 1a5ae3d..bcb31b4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -20,6 +20,7 @@ COPYING
 INSTALL
 aclocal.m4
 autom4te.cache
+configure~
 config.guess
 config.log
 config.status
diff --git a/sources/CONTRIBUTION.md b/sources/CONTRIBUTION.md
index 73f867e..0f7a4a0 100644
--- a/sources/CONTRIBUTION.md
+++ b/sources/CONTRIBUTION.md
@@ -2,3 +2,4 @@
 
 It is suggested for the new contributors to use the following tools:
 - `clang-format` for all the C files, source and headers.
+- `shfmt -ci -i 4 -ln posix` for shell format with the following parameters.
diff --git a/sources/autogen.sh b/sources/autogen.sh
index 712e2b0..39f36c6 100755
--- a/sources/autogen.sh
+++ b/sources/autogen.sh
@@ -1,275 +1,26 @@
-#!/usr/bin/env bash
+#!/bin/sh
 #
-# autogen.sh - Tools for manipulating Jalali representation of Iranian calendar
-# and necessary conversations to Gregorian calendar.
-# Copyright (C) 2006, 2007, 2009, 2010, 2011 Ashkan Ghassemi.
+# Run GNU Autotool commands forcefully to regenerate stuff.
 #
-# This file is part of libjalali.
-#
-# libjalali is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# libjalali is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with libjalali.  If not, see <http://www.gnu.org/licenses/>.
-#
-
-# @OPTIONS
-OPTS="anch"
-LONG_OPTS="nocolor,clean,help,alternative"
-
-# @USAGE
-function usage() {
-	echo -e "Jalali calendar library autogen build script."
-	echo -e "usage: autogen.sh [-nch]"
-	echo -e "try \`autogen.sh --help\' for more information."
-}
-
-# @HELP
-function help() {
-	echo -e "usage: autogen.sh [-nch]..."
-	echo -ne "Invokes GNU build system tools in order to create"
-	echo -e " necessary configuration scripts.\n"
-	echo -e "Operation modes:"
-	echo -e "  -a, --alternative\tdo not invoke autoreconf"
-	echo -e "  -n, --nocolor\t\tdisable output colors"
-	echo -ne "  -c, --clean\t\tremove all auto-generated scripts"
-	echo -e " and files from source tree"
-	echo -e "  -h, --help\t\tprint this help, then exit\n"
-	echo -e "Report bugs to <ghassemi@ftml.net>."
-	echo -e "Jalali calendar home page: <http://nongnu.org/jcal>."
-}
-
-# echoes ``ok'' if parameter is zero, ''failed'' otherwise.
-function printk() {
-	local STAT=$1
-
-	if [ $1 -eq 0 ]; then
-		echo -e "${GREEN}ok${RESET}"
-	else
-		echo -e "${RED}failed${RESET}"
-	fi
-
-	return ${STAT}
-}
-
-# performs make distclean and removes auto-generated files by GNU build system.
-function clean() {
-	local STAT
-	# files
-	local FUBARS=( "autom4te.cache" "Makefile.in" "m4" "aclocal.m4"
-		"configure" "config.sub" "config.guess" "config.log"
-		"config.status" "depcomp" "install-sh" "libtool" "ltmain.sh"
-		"missing" "src/Makefile.in" "man/Makefile.in"
-        "test_kit/jalali/Makefile.in" "test_kit/jalali/Makefile"
-        "test_kit/Makefile.in" "test_kit/Makefile"
-        "test_kit/jalali/.deps" "test_kit/jtime/.deps"
-        "test_kit/jtime/Makefile.in" "test_kit/jalali/Makefile"
-		"libjalali/Makefile.in" "INSTALL" )
-
-	echo -e "${GREEN}*${RESET} ${YELLOW}cleaning source tree...${RESET}"
-
-	# Makefile is present.
-	if test -f Makefile; then
-		echo -ne "${GREEN}* ${RESET}${YELLOW}performing distclean on"
-		echo -ne " sources if possible...${RESET} "
-		make distclean >/dev/null 2>&1
-		let STAT=$?
-
-		printk ${STAT}
-		if [ ${STAT} -ne 0 ]; then
-			echo -ne "${RED}error${RESET}: cannot perform make distclean."
-			echo -e " run make distclean manually and check for erros."
-		fi
-	fi
-
-	for i in ${FUBARS[@]}; do
-		if [ -f $i ] || [ -d $i ]; then
-			echo -ne "${GREEN}*${RESET} ${YELLOW}deleting $i...${RESET} "
-			rm -rf $i
-			printk 0
-		fi
-	done
-
-	echo -e "${GREEN}* done${RESET}"
-}
-
-# Setting colors to vt100 standard values, NULL if 0 gets passed to set_color()
-function set_colors() {
-	local HAS_COLOR=$1
-
-	if [ ${HAS_COLOR} -eq 1 ]; then
-		RED="\033[1;31m"
-		GREEN="\033[1;32m"
-		YELLOW="\033[1;33m"
-		CYAN="\033[1;36m"
-		RESET="\033[0m"
-	else
-		RED=""
-		GREEN=""
-		YELLOW=""
-		CYAN=""
-		RESET=""
-	fi
-}
-
-# @is_present() $SERVICE $NAME $OUTPUT $EXIT
-# Checks whether a service is present on system.
-# $SERVICE is the path to service.
-# $NAME is the service name.
-# $OUTPUT specifies whether is_present() should work silently or not.
-# $EXIT specifies whther is_present() should exit on the event of
-# service not found.
-function is_present() {
-	local SERVICE=$1
-	local NAME=$2
-	local OUTPUT=$3
-	local EXIT=$4
-	local PRESENT=0
-
-	if [ -n "${SERVICE}" ]; then
-		let PRESENT=1
-	fi
-
-	if [ ${OUTPUT} -eq 1 ]; then
-		echo -ne "${GREEN}*${RESET} checking for ${YELLOW}${NAME}${RESET}... "
-		if [ ${PRESENT} -eq 1 ]; then
-			echo -e "${GREEN}yes${RESET}"
-		else
-			echo -e "${RED}no${RESET}"
-		fi
-	fi
-
-	if [ ${PRESENT} -eq 0 ] && [ ${EXIT} -eq 1 ]; then
-		echo -ne "${RED}error${RESET}: ${YELLOW}${NAME}${RESET} was not found"
-		echo -e "on your system. autogen.sh cannot continue."
-		exit 1
-	fi
-
-	return ${PRESENT}
-}
-
-# Checking for tools
-# aclocal, libtoolize, autoconf, automake and autoreconf
-function check_services() {
-	local STAT
-	ACLOCAL="$(which aclocal 2>/dev/null)"
-	is_present "${ACLOCAL}" "aclocal" 1 1
-	# glibtoolize glue-patch
-	LIBTOOLIZE="$(which glibtoolize 2>/dev/null)"
-	STAT=$?
-	is_present "${LIBTOOLIZE}" "glibtoolize" 1 0
-	if [ ${STAT} -ne 0 ]; then
-		LIBTOOLIZE="$(which libtoolize 2>/dev/null)"
-		is_present "${LIBTOOLIZE}" "libtoolize" 1 1
-	fi
-	AUTOCONF="$(which autoconf 2>/dev/null)"
-	is_present "${AUTOCONF}" "autoconf" 1 1
-	AUTOMAKE="$(which automake 2>/dev/null)"
-	is_present "${AUTOMAKE}" "automake" 1 1
-	AUTORECONF="$(which autoreconf 2>/dev/null)"
-	is_present "${AUTORECONF}" "autoreconf" 1 0
-	echo -e "${GREEN}* done${RESET}\n"
-}
-
-# @perform() $SERVICE $NAME $EXIT $PARAMS
-# runs a service with a set of parameters.
-# $SERVICE is the path to the service.
-# $NAME is the service name.
-# $EXIT specifies whether perform() should exit on the event of
-# encoutering any errors or not.
-# $PARAMS are the parameters passed to the service.
-function perform() {
-	local SERVICE=$1
-	local NAME=$2
-	local EXIT=$3
-	local PARAMS=$4
-	local SSTAT
-
-	echo -ne "${GREEN}*${RESET} running ${YELLOW}${NAME}${RESET} ${CYAN}${PARAMS}${RESET}... "
-	${SERVICE} ${PARAMS} >/dev/null 2>&1
-	let STAT=$?
-
-	printk ${STAT}
-
-	if [ ${STAT} -ne 0 ]; then
-		echo -ne "${RED}error${RESET}: cannot run ${YELLOW}${NAME}${RESET}."
-		echo -e " please run ${NAME} manually and check for errors."
-	fi
-
-	if [ ${EXIT} -eq 1 ] && [ ${STAT} -ne 0 ]; then
-		exit 1
-	fi
-}
-
-# Operation modes.
-CLEAN=0
-HELP=0
-COLOR=1
-ALTERN=0
-
-which which 1>/dev/null 2>&1
-if [ $? -ne 0 ]; then
-	echo -e "cannot find \`\`which''. autogen cannot continue."
-	exit 1
+# Reverse the generation by removing any file created (`git clean -fxdn` lists
+# them).
+
+libtoolize="$(command -v libtoolize || command -v glibtoolize)"
+if [ -z "$libtoolize" ]; then
+    printf "libtoolize or glibtoolize is needed and not found.
+		Add to \$PATH or use another way to bootstrap the project.\n"
+    exit 1
 fi
 
-# Parsing command-line arguments
-GETOPT=`which getopt 2>/dev/null`
-if [ -z ${GETOPT} ]; then
-	echo -ne "warning: getopt(1) was not found on your system."
-	echo -e " command line arguments will be ignored."
-else
-	TEMP=`${GETOPT} -o ${OPTS} -l ${LONG_OPTS} -n 'autogen.sh' -- "$@"`
-
-	for i in $TEMP; do
-		case $i in
-			-c|--clean) let CLEAN=1;;
-			-n|--nocolor) let COLOR=0;;
-			-h|--help) let HELP=1;;
-			-a|--alternative) let ALTERN=1;;
-		esac
-	done
-fi
-
-# Setting colors.
-set_colors ${COLOR}
-
-# HELP
-if [ ${HELP} -eq 1 ]; then
-	help
-	exit 0
-fi
-
-# CLEAN
-if [ ${CLEAN} -eq 1 ]; then
-	clean
-	exit 0
-fi
-
-# Checking for services.
-check_services
-
-# alternative method.
-if [ -z "${AUTORECONF}" ] || [ ${ALTERN} -eq 1 ]; then
-	echo -e "using alternative method: ${YELLO}manual${RESET}"
-	perform "${LIBTOOLIZE}" "libtoolize" "1" "--force --copy --install"
-	perform "${ACLOCAL}" "aclocal" "1" "--force"
-	perform "${AUTOMAKE}" "automake" "1" "--add-missing --force-missing --copy"
-	perform "${AUTOCONF}" "autoconf" "1" "--force"
-	echo -e "${GREEN}* done${RESET}"
-# autoreconf method
+"$libtoolize" --force --copy --install || exit 1
+if command -v autoreconf; then
+    printf 'using autoreconf...\n'
+    autoreconf --force --install || exit 1
 else
-	echo -e "using prefered method: ${YELLOW}autoreconf${RESET}"
-	perform "${LIBTOOLIZE}" "libtoolize" "1" "--force --copy --install"
-	perform "${AUTORECONF}" "autoreconf" "1" "--force --install"
-	echo -e "${GREEN}* done${RESET}"
+    printf 'not using autoreconf...\n'
+    aclocal --force || exit 1
+    automake --add-missing --force-missing --copy || exit 1
+    autoconf --force || exit 1
 fi
 
-exit 0
+printf "done. Read the README and INSTALL files.\n"