Mini Shell

#!/usr/bin/sh
# Prints a package's identification PACKAGE VERSION or PACKAGE.
#
# Copyright (C) 2001-2003, 2005, 2014 Free Software Foundation, Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program 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.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

want_version="$1"

# NLS nuisances: Letter ranges are different in the Estonian locale.
LC_ALL=C

while true; do
  if test -f configure; then
    package=`(grep '^PACKAGE_NAME=' configure; grep '^ *PACKAGE=' configure) | grep -v '=[ 	]*$' | sed -e '1q' | sed -e 's/^[^=]*=//' | sed -e "s/^'//" -e "s/'$//"`
    case "$package" in
      *[\"\$\`\{\}]*)
        # Some packages (gcal) retrieve the package name dynamically.
        package=
        ;;
    esac
    if test -n "$package"; then
      is_gnu=`LC_ALL=C grep "GNU $package" * 2>/dev/null | grep -v '^libtool:'`
      if test -n "$is_gnu"; then
        package="GNU $package"
      fi
      if test -n "$want_version"; then
        version=`(grep '^PACKAGE_VERSION=' configure; grep '^ *VERSION=' configure) | grep -v '=[ 	]*$' | sed -e '1q' | sed -e 's/^[^=]*=//' | sed -e "s/^'//" -e "s/'$//"`
        case "$version" in
          *[\"\$\`\{\}]*)
            # Some packages (gcal, gcc, clisp) retrieve the version dynamically.
            version=
            ;;
        esac
        if test -n "$version"; then
          echo "$package $version"
        else
          echo "$package"
        fi
      else
        echo "$package"
      fi
      exit 0
    fi
  fi
  dir=`basename "\`pwd\`"`
  case "$dir" in
    i18n)
      # This directory name, used in GNU make, is not the top level directory.
      ;;
    *[A-Za-z]*[0-9]*)
      package=`echo "$dir" | sed -e 's/^\([^0-9]*\)[0-9].*$/\1/' -e 's/[-_]$//'`
      if test -n "$want_version"; then
        version=`echo "$dir" | sed -e 's/^[^0-9]*\([0-9].*\)$/\1/'`
        echo "$package $version"
      else
        echo "$package"
      fi
      exit 0
      ;;
  esac
  # Go to parent directory
  last=`/bin/pwd`
  cd ..
  curr=`/bin/pwd`
  if test "$last" = "$curr"; then
    # Oops, didn't find the package name.
    if test -n "$want_version"; then
      echo "PACKAGE VERSION"
    else
      echo "PACKAGE"
    fi
    exit 0
  fi
done