configure

#!/bin/sh

# Copyright (C) 2011-2013 Przemyslaw Pawelczyk <przemoc@gmail.com>
#
# This software is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License version 2.
# See <http://www.gnu.org/licenses/gpl-2.0.txt>.
#
# This software 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 General Public License
# for more details.

# minimalistic configure-like script

set -e

SRCDIR="$(dirname $0)"

help() {
	echo \
"Usage: $0 [OPTION]... [VAR=VALUE]...

To assign environment variables (e.g., CC, CFLAGS...), specify them as
VAR=VALUE.  See below for descriptions of some of the useful variables.

Defaults for the options are specified in brackets.

Configuration:
  -h, --help              display this help and exit
      --srcdir=DIR        find the sources in DIR [configure dir]

Installation directories:
  --prefix=PREFIX         install architecture-independent files in PREFIX
                          [/usr/local]
  --exec-prefix=EPREFIX   install architecture-dependent files in EPREFIX
                          [PREFIX]

Fine tuning of the installation directories:
  --bindir=DIR            user executables [EPREFIX/bin]
  --datarootdir=DIR       read-only arch.-independent data root [PREFIX/share]
  --mandir=DIR            man documentation [DATAROOTDIR/man]
  --docdir=DIR            documentation root [DATAROOTDIR/doc/vidma]

System types:
  --host=HOST             cross-compile to build programs to run on HOST

Some influential environment variables:
  CFLAGS       C compiler flags
  LDFLAGS      linker flags
  CPPFLAGS     C/C++/Objective C preprocessor flags
  TARGET_ARCH  Compiler and linker flags regarding target arch, like: -m32
"
	exit 0
}

modify() {
	if [ -n "$OPTARG" ]; then
		CMDS="$CMDS/^$1 /"'s#\([^ ]\?\)= .*#\1= '"$OPTARG#;"
	fi
}

for OPT in "$@"; do
	case "$OPT" in
	*=*)
		OPTARG="$(expr "$OPT" : '[^=]*=\(.*\)' || true)"
		;;
	*)
		OPTARG=""
		;;
	esac
	case "$OPT" in
	-h | --help)     help ;;
	--srcdir=*)      SRCDIR="${OPTARG:-${SRCDIR}}" ;;
	--prefix=*)      modify PREFIX   ;;
	--exec-prefix=*) modify EPREFIX  ;;
	--bindir=*)      modify BINDIR   ;;
	--datarootdir=*) modify DATADIR  ;;
	--mandir=*)      modify MANDIR   ;;
	--docdir=*)      modify DOCDIR   ;;
	--host=*)        modify HOST     ;;
	CC=*)            modify CC       ;;
	CPPFLAGS=*)      modify CPPFLAGS ;;
	CFLAGS=*)        modify CFLAGS   ;;
	LDFLAGS=*)       modify LDFLAGS  ;;
	TARGET_ARCH=*)   modify TARGET_ARCH ;;
	esac
done

OPTARG="$SRCDIR"
modify SRCDIR

sed "$CMDS" "$SRCDIR/Makefile.in" >Makefile