configure

#!/bin/bash
# -*- mode: sh -*-
# Minimal configure script which writes out a Makefile.inc
# Copyright 2010, 2011 Colin Walters <walters@verbum.org>
# Licensed under the new-BSD license (http://www.opensource.org/licenses/bsd-license.php)

prefix=/usr

# Little helper function for reading args from the commandline.
# it automatically handles -a b and -a=b variants, and returns 1 if
# we need to shift $3.
read_arg() {
    # $1 = arg name
    # $2 = arg value
    # $3 = arg parameter
    local rematch='^[^=]*=(.*)$'
    if [[ $2 =~ $rematch ]]; then
        read "$1" <<< "${BASH_REMATCH[1]}"
    else
        read "$1" <<< "$3"
        # There is no way to shift our callers args, so
        # return 1 to indicate they should do it instead.
        return 1
    fi
}

while (($# > 0)); do
    case "${1%%=*}" in
      	--prefix) read_arg prefix "$@" || shift;;
      	--bindir) read_arg bindir "$@" || shift;;
      	--sbindir) read_arg sbindir "$@" || shift;;
      	--libexecdir) read_arg libexecdir "$@" || shift;;
      	--datarootdir) read_arg datarootdir "$@" || shift;;
      	--datadir) read_arg datadir "$@" || shift;;
      	--sysconfdir) read_arg sysconfdir "$@" || shift;;
      	--libdir) read_arg libdir "$@" || shift;;
      	--mandir) read_arg mandir "$@" || shift;;
	*) echo "Ignoring unknown option '$1'";;
    esac
    shift
done

# Handle srcdir != builddir
srcdir=$(dirname $0)
if ! test -f Makefile; then
    ln -s ${srcdir}/Makefile Makefile
fi

cat > Makefile.inc.tmp <<EOF
srcdir = ${srcdir}

prefix ?= ${prefix}
bindir ?= ${bindir:-${prefix}/bin}
sbindir ?= ${sbindir:-${prefix}/sbin}
libexecdir ?= ${libexecdir:-${prefix}/libexec}
datarootdir ?= ${datarootdir:-${prefix}/share}
datadir ?= ${datadir:-${prefix}/share}
sysconfdir ?= ${sysconfdir:-${prefix}/etc}
libdir ?= ${libdir:-${prefix}/lib}
mandir ?= ${mandir:-${prefix}/share/man}
EOF
mv Makefile.inc.tmp Makefile.inc