configure

#!/bin/sh
#/ Usage: ./configure [OPTION]... [VAR=VALUE]...
#/ configure shocco for installation on this system.
#/
#/ Options
#/   --development            configure for local working copy development
#/
#/ Installation locations
#/   --prefix=PREFIX          install files in PREFIX [/usr/local]
#/   --bindir=DIR             user executables [PREFIX/bin]
#/   --sysconfdir=DIR         system configuration files [PREFIX/etc]
#/   --datarootdir=DIR        data file root [PREFIX/share]
#/   --datadir=DIR            data files [DATAROOTDIR]
#/   --mandir=DIR             man documentation [DATAROOTDIR/man]

warn () { echo "$@" 1>&2; }
longarg () { echo "$1" | sed "s/^$2=//"; }

# Argument Parsing
# ----------------

sourcedir="$(cd "$(dirname $0)" && pwd)"
develmode=false

while test $# -gt 0
do
    case "$1" in
    # Options
    --develop|--development)
                       prefix="$sourcedir/work"
                       bindir="$sourcedir"
                       libexecdir="$sourcedir"
                       localstatedir="$prefix"
                       sysconfdir="$sourcedir"
                       datarootdir="$sourcedir"
                       datadir="$sourcedir"
                       mandir="$sourcedir/man"
                       develmode=true
                       shift
                       ;;

    # Installation locations:
    --prefix)          prefix="$2";shift;shift;;
    --prefix=*)        prefix="$(longarg "$1" --prefix)";shift;;
    --bindir)          bindir="$2";shift;shift;;
    --bindir=*)        bindir="$(longarg "$1" --bindir)";shift;;
    --libexecdir)      libexecdir="$2";shift;shift;;
    --libexecdir=*)    libexecdir="$(longarg "$1" --libexecdir)";shift;;
    --localstatedir)   localstatedir="$2";shift;shift;;
    --localstatedir=*) localstatedir="$(longarg "$1" --localstatedir)";shift;;
    --sysconfdir)      sysconfdir="$2";shift;shift;;
    --sysconfdir=*)    sysconfdir="$(longarg "$1" --sysconfdir)";shift;;
    --datarootdir)     datarootdir="$2";shift;shift;;
    --datarootdir=*)   datarootdir="$(longarg "$1" --datarootdir)";shift;;
    --datadir)         datadir="$2";shift;shift;;
    --datadir=*)       datadir="$(longarg "$1" --datadir)";shift;;
    --mandir)          mandir="$2";shift;shift;;
    --mandir=*)        mandir="$(longarg "$1" --mandir)";shift;;

    # Environment variables passed on command line:
    [A-Z]*=*)       name="${1%%=*}"
                    value="${1#*=}"
                    shift
                    eval "${name}='${value}'";;

    # Bail out with usage otherwise.
    *)              grep '^#/' < "$0" | cut -c4-
                    exit 2;;
    esac
done

# Finding Stuff Functions
# -----------------------

looking () { printf "looking $(echo $@)"; }
missing () { printf " (nope)\n"; }
ok ()      { printf " OK\n"; }

found () {
    printf " (${1:-found})"
    test -n "$2" && printf " $2"
    printf "\n"
}

have () {
    for f in "$@"
    do
        # if a whole command line was given, assume it exists
        expr "$f" : '..* ' >/dev/null && {
            echo "$f"
            return 0
        }

        # look for the path with command(1)
        _havepath=$(command -v "$f") || { continue; }
        echo "$_havepath"
        return 0
    done
    return 1
}

# Usage: stdutil <name> <variable> <path>...
stdutil () {
    looking "for $1"; shift
    _varname="$1";    shift
    if _path=$(have "$@")
    then found "$_path"
         reconf $_varname "$_path"
    else missing
         reconf $_varname ""
    fi
    return 0
}

# Build up lists of config stuff to write to config.sh and config.mk
SHCONFIG=
MAKECONFIG=
reconf () {
    SHCONFIG="$SHCONFIG
$1='$2'"
    eval "$SHCONFIG"
    MAKECONFIG="$MAKECONFIG
$1 = $2"
}

UNAME=$(uname 2>/dev/null)
HOST=$(hostname 2>/dev/null)
TIME=$(date 2>/dev/null)

: ${prefix:="/usr/local"}
: ${exec_prefix:="$prefix"}
: ${bindir:="$exec_prefix/bin"}
: ${libexecdir:="$exec_prefix/libexec"}
: ${localstatedir:="$prefix/var"}
: ${sysconfdir:="$prefix/etc"}
: ${datarootdir:="$prefix/share"}
: ${datadir:="$datarootdir"}
: ${mandir:="$datadir/man"}
: ${docdir:="$datadir/doc"}

reconf prefix        "$prefix"
reconf exec_prefix   "$exec_prefix"
reconf bindir        "$bindir"
reconf libexecdir    "$libexecdir"
reconf localstatedir "$localstatedir"
reconf sysconfdir    "$sysconfdir"
reconf datarootdir   "$datarootdir"
reconf datadir       "$datadir"
reconf mandir        "$mandir"
reconf develmode     "$develmode"

PATH="$(getconf PATH 2>/dev/null || echo /usr/bin:/bin)"
PATH="$bindir:$PATH"

test -d "/usr/local" &&
PATH="$PATH:/usr/local/bin"

test "$UNAME" = Darwin -a -d /opt/local &&
PATH="$PATH:/opt/local/bin"

test -d /usr/pkg &&
PATH="$PATH:/usr/pkg/bin"

echo "building for ${UNAME:-unknown}" \
     "on ${HOST:-localhost}"          \
     "at ${TIME:-a time unknown}"

looking "for /bin/sh"
SH=$(have /bin/sh) && {
    if test $(readlink /bin/sh) = dash
    then
        SH=/bin/bash
        found '' "oh ick, it looks like dash. Setting SH to $SH"
    elif expr "$("$SH" --version 2>/dev/null)" : '.*bash' >/dev/null
    then
        found '' "oh ick, it looks like bash"
    else
        found
    fi
} || missing
reconf SHELL "$SH"

stdutil bash       BASH       /bin/bash /usr/bin/bash bash
stdutil dash       DASH       /bin/dash /usr/bin/dash dash

if test "$UNAME" = Darwin
then stdutil open       BROWSER    /usr/bin/open
else stdutil xdg-open   XDG_OPEN   xdg-open
     stdutil firefox    FIREFOX    firefox
     reconf BROWSER "${XDG_OPEN:-$FIREFOX}"
fi

stdutil git        GIT        git
stdutil ronn       RONN       $GEM_PATH/bin/ronn ronn
stdutil shocco     SHOCCO     shocco

set -e

eval "$SHCONFIG"

test -z "$RONN" &&
    warn "warn: ronn is not installed. cannot rebuild manpages. no biggie."

test -z "$SHOCCO" &&
    warn "warn: shocco is not installed. cannot rebuild manpages. no biggie."

echo "okay, looks like you have everything we need. generating config files."

echo writing config.mk...
cat <<EOF > config.mk
$MAKECONFIG
EOF

echo writing config.sh...
cat <<EOF > config.sh
# utility locations
$SHCONFIG
EOF

cat <<MESSAGE
configuration:
  bindir:        $bindir
  mandir:        $mandir
MESSAGE

if $develmode
then echo "okay. ready for development. run \`make' or \`make auto' to build."
else echo "okay. run \`make' to build and \`make install' to install."
fi