Build Tesseract with Autotools on Darwin, link to Leptonica

#!/usr/bin/env bash

#
# Build Tesseract with Autotools on Darwin.
#
# Tested with a MacPorts environment.
#
# Code for a Homebrew environment is here too, but little tested.
# It worked at some point, but it will probably fail for 4.x. It
# should look like the MacPorts command, though.
#

set -ex

#
# A long utility to get the equivalent to readlink -f
#
# TODO add reference from SO.
#
function get_realpath() {
  local queue="$1"
  if [ "${queue}" != "/*" ]
  then
    # Make sure we start with an absolute path.
    queue="${PWD}/${queue}"
  fi
  local current=""
  while [ -n "${queue}" ]
  do
    # Removing a trailing /.
    queue="${queue#/}"
    # Pull the first path segment off of queue.
    local segment="${queue%%/*}"
    # If this is the last segment.
    if [ "${queue}" != "*/*" ]
    then
      segment="${queue}"
      queue=""
    else
      # Remove that first segment.
      queue="${queue#*/}"
    fi
    local link="${current}/${segment}"
    if [ -h "${link}" ]
    then
      link="$(readlink "${link}")"
      queue="${link}/${queue}"
      if [ "${link}" == /* ]
      then
        current=""
      fi
    else
      current="${link}"
    fi
  done
  echo "${current}"
}

#
# The install procedure.
#
# Assuming:
# * The Tesseract repository in tess, under the current directory.
# * A Leptonica build in lept, under the current directory.
#
WDIR="$(get_realpath $(dirname "$0"))"

PREFIX=$WDIR/out
mkdir -p $PREFIX

LEPTONICA_HOME=$WDIR/lept

echo "Will build with Leptonica at $LEPTONICA_HOME"

pushd tess
./autogen.sh
if [ -x '/opt/local/bin/port' ]
then
  echo "Building with MacPorts."
  PKG_CONFIG_PATH=$LEPTONICA_HOME/lib/pkgconfig \
  LIBLEPT_HEADERSDIR=$LEPTONICA_HOME/include ./configure \
    --prefix=$PREFIX \
    --with-extra-libraries=/opt/local/lib \
    --with-extra-libraries=$LEPTONICA_HOME/lib \
    --with-extra-includes=/opt/local/include \
    --with-extra-includes=$LEPTONICA_HOME/include \
    LDFLAGS=-L/opt/local/lib \
    CPPFLAGS=-I/opt/local/include \
    CXXFLAGS=-Wa,-q
elif [ -x '/usr/local/bin/brew' ]
then
  echo "UNTESTED"
  PKG_CONFIG_PATH=$LEPTONICA_HOME/lib/pkgconfig \
  LIBLEPT_HEADERSDIR=$LEPTONICA_HOME/include ./configure \
    --prefix=$PREFIX \
    --with-extra-libraries=$LEPTONICA_HOME/lib \
    --with-extra-includes=$LEPTONICA_HOME/include \
    CC=clang \
    CXX=clang++ \
    CFLAGS="-m64" \
    LDFLAGS="-L/usr/local/opt/icu4c/lib -L$LEPTONICA_HOME/lib" \
    CPPFLAGS="-I/usr/local/opt/icu4c/include -I$LEPTONICA_HOME/include"
else
  echo "Could not find whether to assume MacPorts or Homebrew, aborting."
  popd
  exit 1
fi

make

make install
popd